chemical-physical simulation of polymer based materials http://www.composite-agency.com/ integrated diffusion-chemical-mechanical simulation in order to predict service life, failure, fracture, ageing and fatigue integrated diffusion-chemical-mechanical simulation in order to predict service life, failure, fracture, ageing and fatigue Science & Medicine Natural Sciences en Copyright 2007 contact@composite-agency.com (Composite Agency) contact@composite-agency.com (Composite Agency) 720 27 Jan 2012 22:46:01 GMT 27 Jan 2012 22:46:01 GMT Boten Diffusion - (c) 2002-2010 Composite Agency Take a look at you tube, use search terms likecomosite ansys tutorial, etc.Good luck Take a look at you tube, use search terms likecomosite ansys tutorial, etc.Good luck http://www.composite-agency.com/messages/5279.html#5279 27 Jan 2012 22:46:01 GMT Composite Agency http://www.composite-agency.com/messages/5279.html#5279 Please give me better solution for bonding aluminium and frp. Suggest a better agent Please give me better solution for bonding aluminium and frp. Suggest a better agent http://www.composite-agency.com/messages/5372.html#5372 03 Dec 2011 07:21:25 GMT Vijayaraghavan.M http://www.composite-agency.com/messages/5372.html#5372 Are you involved in composite/laminate materials and is chemical resistance, chemically driven stress, permeation or ageing an issue? Then you should certainly watch this video Are you involved in composite/laminate materials and is chemical resistance, chemically driven stress, permeation or ageing an issue? Then you should certainly watch this video http://www.composite-agency.com/news.htm#5372 04 Nov 2011 12:35:38 GMT Composite Agency http://www.composite-agency.com/news.htm#5372 hiiii am student and in my project i want to do FEA analysis of composite GRP pipe which have sandwich composition,how can i do it in ANSYS ???how to make composite material ???how to make helical winding angles ???and how to give laminate layers so i can check hoop, Axial stress, strain and elasic moduli of GRP pipe hiiii am student and in my project i want to do FEA analysis of composite GRP pipe which have sandwich composition,how can i do it in ANSYS ???how to make composite material ???how to make helical winding angles ???and how to give laminate layers so i can check hoop, Axial stress, strain and elasic moduli of GRP pipe http://www.composite-agency.com/messages/5279.html#5279 23 Oct 2011 17:36:43 GMT Darji Hardik R http://www.composite-agency.com/messages/5279.html#5279 Hi George,Concentrations (of e.g. moisture or solvent) in polymers are influenced by temperature and pressure, but also by degree of crystallinity, by degree of crosslinking, by presence of internal interfaces (from nano and micro fillers, to fibres and laminate surfaces and other potentials such as osmosis (think e.g. of hydrogels, or a chemical reaction releasing product), electrical fields, etc. By using chemical potentials all these effects can be incorporated, giving a precise permeant concentration for a polymer in time and space.For the interfacial robustness of the composite as well as Hi George,Concentrations (of e.g. moisture or solvent) in polymers are influenced by temperature and pressure, but also by degree of crystallinity, by degree of crosslinking, by presence of internal interfaces (from nano and micro fillers, to fibres and laminate surfaces and other potentials such as osmosis (think e.g. of hydrogels, or a chemical reaction releasing product), electrical fields, etc. By using chemical potentials all these effects can be incorporated, giving a precise permeant concentration for a polymer in time and space.For the interfacial robustness of the composite as well as http://www.composite-agency.com/messages/5369.html#5369 06 Oct 2011 17:50:17 GMT Composite Agency http://www.composite-agency.com/messages/5369.html#5369 Dear all:Could you explain in laymen terms why we need chemical potentials to assess the moisture and solvent resistance of our composite laminate? Can't we just mimic expansion stresses in FEM by using thermal expansion coefficient (based on a fluid uptake experiment on a free moving sample)?Kind regards,George Dear all:Could you explain in laymen terms why we need chemical potentials to assess the moisture and solvent resistance of our composite laminate? Can't we just mimic expansion stresses in FEM by using thermal expansion coefficient (based on a fluid uptake experiment on a free moving sample)?Kind regards,George http://www.composite-agency.com/messages/5369.html#5369 06 Oct 2011 12:52:35 GMT George Emsley http://www.composite-agency.com/messages/5369.html#5369 High capacity lithium ion anode materials have always confronted the challenge of volume swelling when electrodes absorb lithium, says Gao Liu of Berkeley Lab's Environmental Energy Technologies Division (EETD), a member of the BATT program (Batteries for Advanced Transportation Technologies) managed by the Lab and supported by DOE's Office of Vehicle Technologies.Says Liu, Most of today's lithium ion batteries have anodes made of graphite, which is electrically conducting and expands only modestly when housing the ions between its graphene layers. Silicon can store 10 times more High capacity lithium ion anode materials have always confronted the challenge of volume swelling when electrodes absorb lithium, says Gao Liu of Berkeley Lab's Environmental Energy Technologies Division (EETD), a member of the BATT program (Batteries for Advanced Transportation Technologies) managed by the Lab and supported by DOE's Office of Vehicle Technologies.Says Liu, Most of today's lithium ion batteries have anodes made of graphite, which is electrically conducting and expands only modestly when housing the ions between its graphene layers. Silicon can store 10 times more http://www.composite-agency.com/news.htm#5369 25 Sep 2011 21:07:23 GMT Composite Agency http://www.composite-agency.com/news.htm#5369 No matter whether you are involved in design for oil and gas equipment, for electronic devices, for civil constructions or for packaging of food, the material requirements become more and more demanding. At the same time, the development in the area of nano layers and nano fillers (think of Graphene) opens a wide range of new possibilities. In the past, plastic based laminates and composites consisted of polymers combined with micro sized materials. Even at that time, lifetime analysis took a lot of effort and rigorous combination of mechanical and chemical resistance knowledge. Now that nano No matter whether you are involved in design for oil and gas equipment, for electronic devices, for civil constructions or for packaging of food, the material requirements become more and more demanding. At the same time, the development in the area of nano layers and nano fillers (think of Graphene) opens a wide range of new possibilities. In the past, plastic based laminates and composites consisted of polymers combined with micro sized materials. Even at that time, lifetime analysis took a lot of effort and rigorous combination of mechanical and chemical resistance knowledge. Now that nano http://www.composite-agency.com/news.htm#5369 21 Sep 2011 21:42:51 GMT Composite Agency http://www.composite-agency.com/news.htm#5369 Frank,Thanks for your comment; interesting and helpful.Regards,Neil Frank,Thanks for your comment; interesting and helpful.Regards,Neil http://www.composite-agency.com/messages/5221.html#5221 05 Sep 2011 21:01:09 GMT Neil Smith http://www.composite-agency.com/messages/5221.html#5221 This is a very interesting subject. Windmill blade lightning failure is often related to the presence of moisture inside the blade. The high temperature of the lightning can drive the accumulated moisture (so water in the microscopic phase, present at fibre interfaces or voids in the laminate) to a sudden steam expansion. Subsequent damage can be,-delamination,-burst bonding,-residue compromise,-longitudinal cracks,-trailing edge cracking,-detached blade pieces,-spar separation or partial or complete blade destruction.There is little rigorous (public) research available on this important This is a very interesting subject. Windmill blade lightning failure is often related to the presence of moisture inside the blade. The high temperature of the lightning can drive the accumulated moisture (so water in the microscopic phase, present at fibre interfaces or voids in the laminate) to a sudden steam expansion. Subsequent damage can be,-delamination,-burst bonding,-residue compromise,-longitudinal cracks,-trailing edge cracking,-detached blade pieces,-spar separation or partial or complete blade destruction.There is little rigorous (public) research available on this important http://www.composite-agency.com/messages/5221.html#5221 12 Jul 2011 11:49:15 GMT Frank http://www.composite-agency.com/messages/5221.html#5221 Dear All:Materials can degrade by chemical surface reaction or internal interfacial reaction. In case of polymer based composite materials, the internal interface reaction of moisture with fibres and fillers is usually the primary concern for the long term since at the proper temperature operation, the matrix is usually chemically resistant. Because this phenomenon is regulated by diffusion rates of water into the matrix and by an internal chemical (equilibrium) reaction, analysis is more complex than the Fick's law based assessment. A proper analysis of the reaction rate and thermodynamical Dear All:Materials can degrade by chemical surface reaction or internal interfacial reaction. In case of polymer based composite materials, the internal interface reaction of moisture with fibres and fillers is usually the primary concern for the long term since at the proper temperature operation, the matrix is usually chemically resistant. Because this phenomenon is regulated by diffusion rates of water into the matrix and by an internal chemical (equilibrium) reaction, analysis is more complex than the Fick's law based assessment. A proper analysis of the reaction rate and thermodynamical http://www.composite-agency.com/messages/5364.html#5364 08 Jul 2011 12:48:31 GMT Composite Agency http://www.composite-agency.com/messages/5364.html#5364 I have a question in a similar direction. We are working with Epoxy based glues for structural bonding in the manufacturing of aero-structures, such as airframes and components. We are more or less able to simulate the mechanical strength of the adhesive with Abaqus. However, we lack proper knowledge on the influence of moisture on the long term behaviour (read: we just follow the predescribed test program without exactly knowing why we are doing things). Hence, I am interested in an overview of theories of water driven failure of epoxy adhesives (or other polymer glues), fillers and I have a question in a similar direction. We are working with Epoxy based glues for structural bonding in the manufacturing of aero-structures, such as airframes and components. We are more or less able to simulate the mechanical strength of the adhesive with Abaqus. However, we lack proper knowledge on the influence of moisture on the long term behaviour (read: we just follow the predescribed test program without exactly knowing why we are doing things). Hence, I am interested in an overview of theories of water driven failure of epoxy adhesives (or other polymer glues), fillers and http://www.composite-agency.com/messages/5364.html#5364 01 Jul 2011 15:20:41 GMT Steve Abbott http://www.composite-agency.com/messages/5364.html#5364 Can someone give me an overview of moisture and salt water induced failure mechanisms of polymers and glass fibre reinforced polymers (such as glass fibre Epoxy composites)? Background of my question is the recent observation of failure (cracks and delamination) of resin based composite subjected to repetitive strains in presence of water and salt. The failure is not predicted by mechanical FEM models for ageing/fatigue (Ansys). Hence, I am looking for ideas for an integrated mechanical-chemical model of composite ageing and failure analysis.Thanks for any suggestion,Marc Atkins Can someone give me an overview of moisture and salt water induced failure mechanisms of polymers and glass fibre reinforced polymers (such as glass fibre Epoxy composites)? Background of my question is the recent observation of failure (cracks and delamination) of resin based composite subjected to repetitive strains in presence of water and salt. The failure is not predicted by mechanical FEM models for ageing/fatigue (Ansys). Hence, I am looking for ideas for an integrated mechanical-chemical model of composite ageing and failure analysis.Thanks for any suggestion,Marc Atkins http://www.composite-agency.com/messages/5364.html#5364 24 Jun 2011 16:30:50 GMT Marc Atkins http://www.composite-agency.com/messages/5364.html#5364 The developed CheFEM software can deal with service life and failure analysis of graphene reinforced Epoxy and thermoplastic materials, like for example Polyamide and PVDF. But have you ever wondered why Graphene is so special? Below a good video which gives a good explanation of what Graphene is, and why it is special. A video that will demonstrate the Graphene properties from the viewpoint of chemical-mechanical composite properties, will follow soon. But first enjoy this one The developed CheFEM software can deal with service life and failure analysis of graphene reinforced Epoxy and thermoplastic materials, like for example Polyamide and PVDF. But have you ever wondered why Graphene is so special? Below a good video which gives a good explanation of what Graphene is, and why it is special. A video that will demonstrate the Graphene properties from the viewpoint of chemical-mechanical composite properties, will follow soon. But first enjoy this one http://www.composite-agency.com/news.htm#5364 08 Jun 2011 18:52:39 GMT Composite Agency http://www.composite-agency.com/news.htm#5364 Thanks for this Thanks for this http://www.composite-agency.com/messages/5358.html#5358 07 Jun 2011 21:22:15 GMT Jonathan http://www.composite-agency.com/messages/5358.html#5358 Offshore Technology Conference in Houston (USA) from 1 May 2011 until 5 May 2011 SOffshore Technology Conference in Houston (USA) from 1 May 2011 until 5 May 2011 http://www.composite-agency.com/news.htm 19 April 2011 10:12:38 GMT Composite Agency http://www.composite-agency.com/news.htm See the graph of mass transfer as function of time for CO2 in PDMS below See the graph of mass transfer as function of time for CO2 in PDMS below http://www.composite-agency.com/messages/5358.html#5358 05 May 2011 10:12:38 GMT Jonathan http://www.composite-agency.com/messages/5358.html#5358 delta h for styrene is 4.1please correct it delta h for styrene is 4.1please correct it http://www.composite-agency.com/messages/5344.html#5344 24 Apr 2011 10:22:24 GMT Majid http://www.composite-agency.com/messages/5344.html#5344 Dear Jonathan, In this case the diffusion coefficient seemingly decreases, with an increase of concentration of carbon dioxide in the elastomer membrane. This is the opposite of what normally happens with plasticizing and swelling: an increase of the diffusivity (or decrease of the mutual friction coefficient) as function of the permeant concentration. From various rubbers this is known to happen with molecules like Water and CO2. These molecules cause a better ordening and dipole-dipole / hydrogen bonding in the chain structure of these rubbers. Mind that filler particles do also influence Dear Jonathan, In this case the diffusion coefficient seemingly decreases, with an increase of concentration of carbon dioxide in the elastomer membrane. This is the opposite of what normally happens with plasticizing and swelling: an increase of the diffusivity (or decrease of the mutual friction coefficient) as function of the permeant concentration. From various rubbers this is known to happen with molecules like Water and CO2. These molecules cause a better ordening and dipole-dipole / hydrogen bonding in the chain structure of these rubbers. Mind that filler particles do also influence http://www.composite-agency.com/messages/5358.html#5358 18 Apr 2011 11:23:44 GMT Composite Agency http://www.composite-agency.com/messages/5358.html#5358 I'm studying carbon dioxide (CO2) diffusion through PDMS (poly dimethyl siloxane polymer, silicone rubber) thin membrane (0.02''). The feed pressure Po of carbon dioxide is held constant over the diffusion time. For small values of Po (5 Torr), the flux of CO2 passing through the polymer membrane in function of time as a Fickian diffusion. The problem occurs when I increase the Po where I observe a strange diffusion behavior. At the beginning of the plot, the flux of CO2 shows a normal increase. At maximal flux, where the steedy state is suppose to occur, the curve suddenly begin to drop and I'm studying carbon dioxide (CO2) diffusion through PDMS (poly dimethyl siloxane polymer, silicone rubber) thin membrane (0.02''). The feed pressure Po of carbon dioxide is held constant over the diffusion time. For small values of Po (5 Torr), the flux of CO2 passing through the polymer membrane in function of time as a Fickian diffusion. The problem occurs when I increase the Po where I observe a strange diffusion behavior. At the beginning of the plot, the flux of CO2 shows a normal increase. At maximal flux, where the steedy state is suppose to occur, the curve suddenly begin to drop and http://www.composite-agency.com/messages/5358.html#5358 08 Apr 2011 10:54:17 GMT Jonathan http://www.composite-agency.com/messages/5358.html#5358 Hi,In the past this website contained various valuable tables on diffusion and solubility of liquids and gases in polymers and composites (thermosets and thermoplastic materials), including solubility parameter data and chemical ageing figures. I am looking for this data, but cannot find anything. Have these tables been removed, and if yes, could they please be made available again?Thanks,Maria Hi,In the past this website contained various valuable tables on diffusion and solubility of liquids and gases in polymers and composites (thermosets and thermoplastic materials), including solubility parameter data and chemical ageing figures. I am looking for this data, but cannot find anything. Have these tables been removed, and if yes, could they please be made available again?Thanks,Maria http://www.composite-agency.com/messages/5344.html#5344 04 Apr 2011 16:15:31 GMT Maria http://www.composite-agency.com/messages/5344.html#5344 Hi, Thanks for your reply.No sorry I don't mean NH3, that is chemical attack and not biological. Apologies I should have made my post clearer, I meant bacteria or bugs. I am aware that most long chain polymers are actually very resistant to bacteria, hence the issue with making polymers biodegradable, but I was wondering if anyone had specific experience of biological attack/resistance of TPE's.By the way in materials engineering (my field) the polyamide and water mech properties issue is well documented. That is related to the hygroscopic pros of the polyamide - google nylon and water, it is Hi, Thanks for your reply.No sorry I don't mean NH3, that is chemical attack and not biological. Apologies I should have made my post clearer, I meant bacteria or bugs. I am aware that most long chain polymers are actually very resistant to bacteria, hence the issue with making polymers biodegradable, but I was wondering if anyone had specific experience of biological attack/resistance of TPE's.By the way in materials engineering (my field) the polyamide and water mech properties issue is well documented. That is related to the hygroscopic pros of the polyamide - google nylon and water, it is http://www.composite-agency.com/messages/5341.html#5341 04 Mar 2011 14:05:35 GMT billy murphy http://www.composite-agency.com/messages/5341.html#5341 Dear Billy,Is there any indication of what sort of TPE is used or is of preferential use? By biological attack, do you mean fugitive emissions of e.g. NH3? This depends on a lot of physical-chemical parameters, which requires quite specific insight in the application, processing, etc.You can be quite sure that the TPE loses mechanical properties in the presence of the urine. How much exactly depends on many factors. I cannot give you any bootstrap indication because the analysis is complex, for example read this (from another recent forum post): I found that dry Polyamide 6 has an E modulus Dear Billy,Is there any indication of what sort of TPE is used or is of preferential use? By biological attack, do you mean fugitive emissions of e.g. NH3? This depends on a lot of physical-chemical parameters, which requires quite specific insight in the application, processing, etc.You can be quite sure that the TPE loses mechanical properties in the presence of the urine. How much exactly depends on many factors. I cannot give you any bootstrap indication because the analysis is complex, for example read this (from another recent forum post): I found that dry Polyamide 6 has an E modulus http://www.composite-agency.com/messages/5341.html#5341 04 Mar 2011 12:21:29 GMT Composite Agency http://www.composite-agency.com/messages/5341.html#5341 Hi I am investigating the use of TPE in a dairy farming environment - specifically with exposure to cow dung/urine, aside from the potential for chemical attack is there any risk of biological attack? We are specifically concerned with loss of mechanical properties. Could anyone point me towards some resources that IO might use to investigate this or if anyone has any info or direct experience of using TPE in animal waste I would appreciate your insights Hi I am investigating the use of TPE in a dairy farming environment - specifically with exposure to cow dung/urine, aside from the potential for chemical attack is there any risk of biological attack? We are specifically concerned with loss of mechanical properties. Could anyone point me towards some resources that IO might use to investigate this or if anyone has any info or direct experience of using TPE in animal waste I would appreciate your insights http://www.composite-agency.com/messages/5341.html#5341 04 Mar 2011 10:01:45 GMT billy murphy http://www.composite-agency.com/messages/5341.html#5341 From the CheFEM section I understood that glass fibre reinforcement can restrain chemically driven expansion (so the reduction in expansions is more than proportional than the volume of fibres)I found that dry Polyamide 6 has an E modulus of 3.1 GPa, with 3% wt% Water E becomes 1.1 GPa, and with wt% 6% Water it decreases to 0.7 GPa. In presence of bio Ethanol (the opposite side in our application), the figures won't be much better. Nevertheless, our application works quite well in real-life. Can this be due to the swelling restraint as predicted by the CheFEM simulation software. Could we From the CheFEM section I understood that glass fibre reinforcement can restrain chemically driven expansion (so the reduction in expansions is more than proportional than the volume of fibres)I found that dry Polyamide 6 has an E modulus of 3.1 GPa, with 3% wt% Water E becomes 1.1 GPa, and with wt% 6% Water it decreases to 0.7 GPa. In presence of bio Ethanol (the opposite side in our application), the figures won't be much better. Nevertheless, our application works quite well in real-life. Can this be due to the swelling restraint as predicted by the CheFEM simulation software. Could we http://www.composite-agency.com/messages/5340.html#5340 21 Feb 2011 15:30:02 GMT Tom Christiansen http://www.composite-agency.com/messages/5340.html#5340 Dear All:With reference to the news topic on this site cracks in composite rotor blades in Eemshaven, I am wondering what the root cause is for these unexpected mechanical failures in wind mill rotor blades. Is it caused by design flaws incorrect FEM mechanical stress and strain models, processing of the composite too much moisture in the workroom, insufficient thermal epoxy curing, insufficient rigorous testing and regulations standards, unforeseen chemically Dear All:With reference to the news topic on this site cracks in composite rotor blades in Eemshaven, I am wondering what the root cause is for these unexpected mechanical failures in wind mill rotor blades. Is it caused by design flaws incorrect FEM mechanical stress and strain models?, processing of the composite (too much moisture in the workroom, insufficient thermal epoxy curing), insufficient rigorous testing and regulations standards, unforeseen chemically http://www.composite-agency.com/messages/5339.html#5339 24 Jan 2011 15:19:56 GMT Dennis Alezzi http://www.composite-agency.com/messages/5339.html#5339 Dear All:With reference to the news topic on this site cracks in composite rotor blades in Eemshaven, I am wondering what the root cause is for these unexpected mechanical failures in wind mill rotor blades. Is it caused by design flaws incorrect FEM mechanical stress and strain models?, processing of the composite (too much moisture in the workroom, insufficient thermal epoxy curing), insufficient rigorous testing and regulations standards, unforeseen chemically Dear All:With reference to the news topic on this site cracks in composite rotor blades in Eemshaven, I am wondering what the root cause is for these unexpected mechanical failures in wind mill rotor blades. Is it caused by design flaws (incorrect FEM mechanical stress and strain models?), processing of the composite (too much moisture in the workroom, insufficient thermal epoxy curing), insufficient rigorous testing and regulations standards, unforeseen chemically http://www.composite-agency.com/news.htm#5339 24 Jan 2011 15:19:36 GMT Composite Agency http://www.composite-agency.com/news.htm#5339 I must say that I like the integration of chemical simulation with mechanical FEM analysis (and then calling it CheFEM is simply wicked!). If we would have to test a polymer against for Rapid Gas Decompression (RGD) according to NORSOK M710, API 17K and 17J NACE TM0192 and TM0297, TOTALELFFINA SP TCS 142 Appendix H, how could a device like CheFEM be helpful? Regards,Frank Smither I must say that I like the integration of chemical simulation with mechanical FEM analysis (and then calling it CheFEM is simply wicked!). If we would have to test a polymer against for Rapid Gas Decompression (RGD) according to NORSOK M710, API 17K and 17J NACE TM0192 and TM0297, TOTALELFFINA SP TCS 142 Appendix H, how could a device like CheFEM be helpful? Regards,Frank Smither http://www.composite-agency.com/messages/5338.html#5338 06 Dec 2010 18:33:28 GMT Frank Smither http://www.composite-agency.com/messages/5338.html#5338 Dear Julia,CheFEM usually uses Finite Difference Methodology (FDM) for solubility and diffusion calculations regarding multilayer / laminate materials. Large magnitudes in layer thicknesses and interfacial concentrations can be handled much more efficient and effective with FDM (compared to FEM). Subsequently, stresses and strains are quantified using classic laminate theory and/or FEM. Especially if the laminate is subjected to external stresses (a mechanical load), intrinsic stresses (complex shapes, 90 and 180 degrees bends) and/or residual stresses (thermal), FEM is the best method for the Dear Julia,CheFEM usually uses Finite Difference Methodology (FDM) for solubility and diffusion calculations regarding multilayer / laminate materials. Large magnitudes in layer thicknesses and interfacial concentrations can be handled much more efficient and effective with FDM (compared to FEM). Subsequently, stresses and strains are quantified using classic laminate theory and/or FEM. Especially if the laminate is subjected to external stresses (a mechanical load), intrinsic stresses (complex shapes, 90 and 180 degrees bends) and/or residual stresses (thermal), FEM is the best method for the http://www.composite-agency.com/messages/5336.html#5336 06 Dec 2010 17:56:38 GMT Composite Agency http://www.composite-agency.com/messages/5336.html#5336 Hi,How does CheFEM treat water permeation in multilayer materials? My FEM software is not able to deal with solubility and diffusivity in a sequence of nanoscopic and microscopic layers (and yes, I know it is based on Fick's first and second law, but I justed wanted to obtain a worst case indication of the permeation, but even that is seemingly too much...).Thanks for your help.Kind Regards,Julia Hi,How does CheFEM treat water permeation in multilayer materials? My FEM software is not able to deal with solubility and diffusivity in a sequence of nanoscopic and microscopic layers (and yes, I know it is based on Fick's first and second law, but I justed wanted to obtain a worst case indication of the permeation, but even that is seemingly too much...).Thanks for your help.Kind Regards,Julia http://www.composite-agency.com/messages/5336.html#5336 29 Nov 2010 21:20:46 GMT Julia Emsley http://www.composite-agency.com/messages/5336.html#5336 I am interested in Abaqus material models of plain and glass reinforced polymers mainly PC and ABS based.We in order to enhance the FEA simulations results with the product test data we are looking into redefining material models definitions. Is anyone able to defining the non-linear, strain rate dependent, elasto-plastic, polymer abaqus model for these polymers? Both plain and fiber reinforced?Kind Regards,Karl I am interested in Abaqus material models of plain and glass reinforced polymers mainly PC and ABS based.We in order to enhance the FEA simulations results with the product test data we are looking into redefining material models definitions. Is anyone able to defining the non-linear, strain rate dependent, elasto-plastic, polymer abaqus model for these polymers? Both plain and fiber reinforced?Kind Regards,Karl http://www.composite-agency.com/messages/5335.html#5335 26 Nov 2010 14:18:43 GMT Karl http://www.composite-agency.com/messages/5335.html#5335 The Valve World Expo is the leading trade fair for valves and valve equipment. The Valve World Expo is the leading trade fair for valves and valve equipment. In 2010, it will take place for the first time at its new location in Dusseldorf. Trade visitors from the sectors Oil and gas, chemical industry, power supply industry, marine, refinery and offshore industry, machine and plant construction, ship building, motor and vehicle construction, and food processing industry all use the fast-paced developments of valve technology, which are shown comprehensively at the Valve World Expo The Valve World Expo is the leading trade fair for valves and valve equipment. The Valve World Expo is the leading trade fair for valves and valve equipment. In 2010, it will take place for the first time at its new location in Dusseldorf. Trade visitors from the sectors Oil and gas, chemical industry, power supply industry, marine, refinery and offshore industry, machine and plant construction, ship building, motor and vehicle construction, and food processing industry all use the fast-paced developments of valve technology, which are shown comprehensively at the Valve World Expo http://www.composite-agency.com/news.htm#5335 24 Nov 2010 22:15:11 GMT Composite Agency http://www.composite-agency.com/news.htm#5335 Hi there,I just want to say thank you for the development of CheFEM (chemical potential based FEM simulation of thermoset and thermoplastic composites). I have always been convinced that the use of composite materials could be extended to severe temperature and pressure conditions (severe cycling / spiking), once the appropriate simulation tool would be available. CheFEM will surely help to define the correct laminate build-up, processing conditions for a wide range of new applications.The last work I read on chemical effects on composite materials was the book by George Springer ( Hi there,I just want to say thank you for the development of CheFEM (chemical potential based FEM simulation of thermoset and thermoplastic composites). I have always been convinced that the use of composite materials could be extended to severe temperature and pressure conditions (severe cycling / spiking), once the appropriate simulation tool would be available. CheFEM will surely help to define the correct laminate build-up, processing conditions for a wide range of new applications.The last work I read on chemical effects on composite materials was the book by George Springer ( http://www.composite-agency.com/messages/5334.html#5334 09 Nov 2010 22:17:03 GMT Julia Emsley http://www.composite-agency.com/messages/5334.html#5334 Thank you for the information. Apologies for my slow response but I was on leave.Best Regards,Martin Thank you for the information. Apologies for my slow response but I was on leave.Best Regards,Martin http://www.composite-agency.com/messages/5328.html#5328 21 Oct 2010 00:53:09 GMT Martin Deehan http://www.composite-agency.com/messages/5328.html#5328 Thanks for the prompt reply!Also sounds quite useful for service life prediction (emission and failure assessment) of FRP tanks and pipes for containment of acids, alkali and strong solvents (glycerol). Is there any case study on GRP laminate?Pierre Thanks for the prompt reply!Also sounds quite useful for service life prediction (emission and failure assessment) of FRP tanks and pipes for containment of acids, alkali and strong solvents (glycerol). Is there any case study on GRP laminate?Pierre http://www.composite-agency.com/messages/5327.html#5327 18 Oct 2010 14:32:13 GMT Pierre Garnier http://www.composite-agency.com/messages/5327.html#5327 Dear Pierre,In a nutshell, CheFEM adds chemical thermodynamic interaction into nowadays FEM based composite service life analysis. The presence of chemicals at the composite surface or inside the composite (as a result of diffusion or capillary processes) gives rise to expansion stresses, corrosion phenomena, accumulation of chemicals at certain spots, etc. CheFEM quantifies the forthcoming chemical potentials and concentrations in the time-space domain. Subsequently this matrix is used in FEM based lifetime and fracture analysis (where mechanical stresses and strains are incorporated) and for Dear Pierre,In a nutshell, CheFEM adds chemical thermodynamic interaction into nowadays FEM based composite service life analysis. The presence of chemicals at the composite surface or inside the composite (as a result of diffusion or capillary processes) gives rise to expansion stresses, corrosion phenomena, accumulation of chemicals at certain spots, etc. CheFEM quantifies the forthcoming chemical potentials and concentrations in the time-space domain. Subsequently this matrix is used in FEM based lifetime and fracture analysis (where mechanical stresses and strains are incorporated) and for http://www.composite-agency.com/messages/5327.html#5327 13 Oct 2010 14:04:46 GMT Composite Agency http://www.composite-agency.com/messages/5327.html#5327 You might try Silicone foams. A number of suppliers I know: NuSil, Rogers corporation, Bluestar and DowCorning provide Silicone foams. I can't say the temp capability of each, however, Silicones can operate at 300 C You might try Silicone foams. A number of suppliers I know: NuSil, Rogers corporation, Bluestar and DowCorning provide Silicone foams. I can't say the temp capability of each, however, Silicones can operate at 300 C http://www.composite-agency.com/messages/4538.html 11 Oct 2010 23:01:38 GMT jake http://www.composite-agency.com/messages/4538.html#4538 Dear Martin,In line with the thermodynamics and diffusion theory, the Helium solubility (S) should be in the order of 1E-2- 1E-3 m3/m3 atm and the diffusivity (D) in the order of 1E-9 - 1E-10 m2/s at room temperature (25 degrees Celsius) and 1 atm pressure. This gives for the permeation rate (Pstp=DxS): 1E-11 - 1E-13 [m3/m3 atm] x [m2/s].To obtain the permeation rate in mass, multiply this figure by the Helium density at room temperature and 1 atm pressure. Using ideal gas law: Helium 1.6 e2 gram/m3,Pmass ~ 1 E-11 - 1 E-13 gram / m x sDivide P by O-ring thickness [m] and subsequently multiply Dear Martin,In line with the thermodynamics and diffusion theory, the Helium solubility (S) should be in the order of 1E-2- 1E-3 m3/m3 atm and the diffusivity (D) in the order of 1E-9 - 1E-10 m2/s at room temperature (25 degrees Celsius) and 1 atm pressure. This gives for the permeation rate (Pstp=DxS): 1E-11 - 1E-13 [m3/m3 atm] x [m2/s].To obtain the permeation rate in mass, multiply this figure by the Helium density at room temperature and 1 atm pressure. Using ideal gas law: Helium 1.6 e2 gram/m3,Pmass ~ 1 E-11 - 1 E-13 gram / m x sDivide P by O-ring thickness [m] and subsequently multiply http://www.composite-agency.com/messages/5328.html#5328 11 Oct 2010 11:29:49 GMT Composite Agency http://www.composite-agency.com/messages/5328.html#5328 I am trying to find out the permeation rate of Helium through the above oring type (believed from Parker) I understand there may be variations lot to lot but general indications would be helpful.FYI I am troubleshooting a vacuum leak in an etch chamber I am trying to find out the permeation rate of Helium through the above oring type (believed from Parker) I understand there may be variations lot to lot but general indications would be helpful.FYI I am troubleshooting a vacuum leak in an etch chamber http://www.composite-agency.com/messages/5328.html 03 Oct 2010 20:43:32 GMT Martin Deehan http://www.composite-agency.com/messages/5328.html Composite Agency is currently performing an integrated simulation analysis of barrier, ageing and fracture behaviour of Functionalized Graphene Sheets (FGS) based coatings and composites. The following configurations are analysed:- Polyurethane and Epoxy filled with FGS (coating applications for severe temperature and pressure variations).- Polyamide (Nylon) reinforced with FGS (structural aerospace applications)The assessment is carried our using CheFEM (Chemical potential driven FEM simulation of advanced composites).Do you wonder what Graphene or FGS based polymers can do for you? We can Composite Agency is currently performing an integrated simulation analysis of barrier, ageing and fracture behaviour of Functionalized Graphene Sheets (FGS) based coatings and composites. The following configurations are analysed:- Polyurethane and Epoxy filled with FGS (coating applications for severe temperature and pressure variations).- Polyamide (Nylon) reinforced with FGS (structural aerospace applications)The assessment is carried our using CheFEM (Chemical potential driven FEM simulation of advanced composites).Do you wonder what Graphene or FGS based polymers can do for you? We can http://www.composite-agency.com/news.htm#5328 26 Sep 2010 12:29:14 GMT Composite Agency http://www.composite-agency.com/news.htm#5328 Dear All:I am interested in a more throughout description of the advantages of CheFEM compared to existing FEM packages like Abaqus, Ansys and Nastran. All these packages also include mass diffusion and solubility properties, corrosion rates, also applicable in a wide range of polymer based configurations. From the CheFEM section, I clearly understand that the input of the FEM module are chemical potentials (instead of stress and strain in the other packages), but the theoretical and practical consequences of this approach (besides the dealing with vapours and supercritical gases) are not Dear All:I am interested in a more throughout description of the advantages of CheFEM compared to existing FEM packages like Abaqus, Ansys and Nastran. All these packages also include mass diffusion and solubility properties, corrosion rates, also applicable in a wide range of polymer based configurations. From the CheFEM section, I clearly understand that the input of the FEM module are chemical potentials (instead of stress and strain in the other packages), but the theoretical and practical consequences of this approach (besides the dealing with vapours and supercritical gases) are not http://www.composite-agency.com/messages/5327.html 16 Sep 2010 16:24:01 GMT Pierre Garnier http://www.composite-agency.com/messages/5327.html Wajid,This problem looks simple (look for example on stress or hydrostatic pressure calculation of thin or thick walled cylinder - be warned that thin walled or thick walled is a totally different story), but the thermodynamical driven (temperature and water diffusion) problems in this configuration usually come from interfacial shear (mode II fracture) and interfacial normal stresses (mode I fracture) at the HDPE-CS interface. There is no simple approach to this, also visit the CheFEM page on this website.Kind Regards,Composite Agency Wajid,This problem looks simple (look for example on stress or hydrostatic pressure calculation of thin or thick walled cylinder - be warned that thin walled or thick walled is a totally different story), but the thermodynamical driven (temperature and water diffusion) problems in this configuration usually come from interfacial shear (mode II fracture) and interfacial normal stresses (mode I fracture) at the HDPE-CS interface. There is no simple approach to this, also visit the CheFEM page on this website.Kind Regards,Composite Agency http://www.composite-agency.com/messages/5216.html 13 Sep 2010 13:41:03 GMT Composite Agency http://www.composite-agency.com/messages/5216.html Dear Iris,My impression - also on basis of your description of the situation - is that the exact PP grade is quite important for the service life in the conditions quoted. Concentrations and temperature are indeed important factors in case the polymer is not totally intrinsically chemical resistant.Although the producer in China might provide you with the proper and correct data, you could also (or in addition) take a sample, which could be analyzed (independently) by us, in line with various of the items you stated above and degree of crystallinity. Please feel free to contact us for any Dear Iris,My impression - also on basis of your description of the situation - is that the exact PP grade is quite important for the service life in the conditions quoted. Concentrations and temperature are indeed important factors in case the polymer is not totally intrinsically chemical resistant.Although the producer in China might provide you with the proper and correct data, you could also (or in addition) take a sample, which could be analyzed (independently) by us, in line with various of the items you stated above and degree of crystallinity. Please feel free to contact us for any http://www.composite-agency.com/messages/5316.html 08 Sep 2010 21:34:10 GMT Composite Agency http://www.composite-agency.com/messages/5316.html Dear Mechanical Design,It is not easy to give a general answer to this. Especially in several limiting situations (think for example of the function 1/x limiting to zero), FEM solutions have the tendency to become far from being accurate. So, if the problem can be solved with an exact analytical solution, this is usually better. For a good handbook for mechanically oriented formulae, I would like to recommend Roark's formulas for stress and strain. Only if the dimensions and configurations are too complex for the analytical results (the pain in composite engineering is that these are 99% of Dear Mechanical Design,It is not easy to give a general answer to this. Especially in several limiting situations (think for example of the function 1/x limiting to zero), FEM solutions have the tendency to become far from being accurate. So, if the problem can be solved with an exact analytical solution, this is usually better. For a good handbook for mechanically oriented formulae, I would like to recommend Roark's formulas for stress and strain. Only if the dimensions and configurations are too complex for the analytical results (the pain in composite engineering is that these are 99% of http://www.composite-agency.com/messages/5323.html 07 Sep 2010 10:15:57 GMT Composite Agency http://www.composite-agency.com/messages/5323.html Good afternoon,How I observed on some articles which develop subject of stress-strain curve, appear some FEM results and with FEM results is compare analytical calculus and experimental calculus.My question is how can be construct curve stress-strain for material using material data like :modulus of elasticity, Poisson coef., density of material.Can be combined FEM power with analytical calculus in a manner in which values obtain from FEM is entered in analytical calculus and the results from analytical calculus is entered in FEM, in an iterative manner ?Thank you for understanding and best Good afternoon,How I observed on some articles which develop subject of stress-strain curve, appear some FEM results and with FEM results is compare analytical calculus and experimental calculus.My question is how can be construct curve stress-strain for material using material data like :modulus of elasticity, Poisson coef., density of material.Can be combined FEM power with analytical calculus in a manner in which values obtain from FEM is entered in analytical calculus and the results from analytical calculus is entered in FEM, in an iterative manner ?Thank you for understanding and best http://www.composite-agency.com/messages/5323.html 06 Sep 2010 17:31:39 GMT mechanicaldesign http://www.composite-agency.com/messages/5323.html Well that's al bit of a problem to find out. It is an filter of a competitor. So I'm trying to find it out but it doesn't go fast..On the other hand there are filters in other swimming pools that the PP media doesn't break so it looks like it is a mistery. (concentrations chlorine are not so high so the oxidation might not go fast) I got little resources here to investigate it so i have to find out as much litrature to ask some things at the supplier (and that is in China). So my main questions are:What is the melt flow rate?What is the moleculair weight? What kind of additives are used during Well that's al bit of a problem to find out. It is an filter of a competitor. So I'm trying to find it out but it doesn't go fast..On the other hand there are filters in other swimming pools that the PP media doesn't break so it looks like it is a mistery. (concentrations chlorine are not so high so the oxidation might not go fast) I got little resources here to investigate it so i have to find out as much litrature to ask some things at the supplier (and that is in China). So my main questions are:What is the melt flow rate?What is the moleculair weight? What kind of additives are used during http://www.composite-agency.com/messages/5316.html 02 Sep 2010 08:59:11 GMT Iris Dijkhuizen http://www.composite-agency.com/messages/5316.html Well that's al bit of a problem to find out. It is an filter of a competitor. So I'm trying to find it out but it doesn't go fast..On the other hand there are filters in other swimming pools that the PP media doesn't break so it looks like it is a mistery. (concentrations chlorine are not so high so the oxidation might not go fast) I got little resources here to investigate it so i have to find out as much litrature to ask some things at the supplier (and that is in China). So my main questions are:What is the melt flow rate?What is the moleculair weight? What kind of additives are used during Well that's al bit of a problem to find out. It is an filter of a competitor. So I'm trying to find it out but it doesn't go fast..On the other hand there are filters in other swimming pools that the PP media doesn't break so it looks like it is a mistery. (concentrations chlorine are not so high so the oxidation might not go fast) I got little resources here to investigate it so i have to find out as much litrature to ask some things at the supplier (and that is in China). So my main questions are:What is the melt flow rate?What is the moleculair weight? What kind of additives are used during http://www.composite-agency.com/messages/5316.html 02 Sep 2010 08:25:12 GMT Iris http://www.composite-agency.com/messages/5316.html Thanks Frank Thanks Frank http://www.composite-agency.com/messages/5316.html 01 Sep 2010 18:34:51 GMT Composite Agency http://www.composite-agency.com/messages/5316.html Iris,In line with the comments of Composite Agency, is there any difference in PP property information of the different suppliers? Is the chemical loading (read: concentration of Chlorine gas) in both swimming pool applications equal?Regards,Frank Iris,In line with the comments of Composite Agency, is there any difference in PP property information of the different suppliers? Is the chemical loading (read: concentration of Chlorine gas) in both swimming pool applications equal?Regards,Frank http://www.composite-agency.com/messages/5316.html 01 Sep 2010 18:26:54 GMT Frank http://www.composite-agency.com/messages/5316.html Charles and Composite Agency,You are welcome Charles and Composite Agency,You are welcome http://www.composite-agency.com/messages/5308.html 26 Aug 2010 16:01:37 GMT Sylvia http://www.composite-agency.com/messages/5308.html Dear Iris,You might be right that PP is not resistant to Chlorine gas. Also according to our information PP is not quite resistant to Chlorine gas, either dry or wet, neither Chlorine in the liquid state. This means that a corrosion front might move through the material (with a certain rate, for example, say 0.1 mm/year), which cuts the polymer chains, subsequently resulting in loss of mechanical strength.It is very well possible that Polypropylene with better mechanical properties (check for example the degree of crystallinity and/the average/distribution in molecular weight) will show slower Dear Iris,You might be right that PP is not resistant to Chlorine gas. Also according to our information PP is not quite resistant to Chlorine gas, either dry or wet, neither Chlorine in the liquid state. This means that a corrosion front might move through the material (with a certain rate, for example, say 0.1 mm/year), which cuts the polymer chains, subsequently resulting in loss of mechanical strength.It is very well possible that Polypropylene with better mechanical properties (check for example the degree of crystallinity and/the average/distribution in molecular weight) will show slower http://www.composite-agency.com/messages/5316.html 26 Aug 2010 14:59:44 GMT Composite Agency http://www.composite-agency.com/messages/5316.html Dear sir/madam,I’m trying to start a question at you forum but it won’t allow me. This was my following question.chemical resistance of ppDear all,I hope this is the right forum for my questions. Excuse me for my poor English but I will try.At this moment I am researching a problem with air filters made from polypropylene. I got a filter what is damaged. I think that the filter media broke because of chemical oxidation of chlorine gas (in a swimming pool). I did some research and I think this is a correct explanation because PP is not resistant to strong oxidizing agents. www.andrewwebron Dear sir/madam,I’m trying to start a question at you forum but it won’t allow me. This was my following question.chemical resistance of ppDear all,I hope this is the right forum for my questions. Excuse me for my poor English but I will try.At this moment I am researching a problem with air filters made from polypropylene. I got a filter what is damaged. I think that the filter media broke because of chemical oxidation of chlorine gas (in a swimming pool). I did some research and I think this is a correct explanation because PP is not resistant to strong oxidizing agents. www.andrewwebron http://www.composite-agency.com/messages/5316.html 26 Aug 2010 14:03:19 GMT Iris Dijkhuizen http://www.composite-agency.com/messages/5316.html Composite Agency and Sylvia,Thanks for your help.Charles Composite Agency and Sylvia,Thanks for your help.Charles http://www.composite-agency.com/messages/5308.html 25 Aug 2010 19:56:46 GMT Charles http://www.composite-agency.com/messages/5308.html And some more info on the design pressure And some more info on the design pressure http://www.composite-agency.com/messages/5216.html 25 Aug 2010 18:27:12 GMT Composite Agency http://www.composite-agency.com/messages/5216.html Wajid,Thanks for rejuvenating this subject. What sort of dimensions are your interested (this is important since thin wall cylindrical solutions are quite different from thick wall cylindrical solutions)?Kind Regards,Composite Agency Wajid,Thanks for rejuvenating this subject. What sort of dimensions are your interested (this is important since thin wall cylindrical solutions are quite different from thick wall cylindrical solutions)?Kind Regards,Composite Agency http://www.composite-agency.com/messages/5216.html 25 Aug 2010 18:19:08 GMT Composit Agency http://www.composite-agency.com/messages/5216.html Hi Nick,I have seen various discussion from you on this topic. I am quite beginner in this topic. I appreciate if a detail discussion on how the stresses can be calculated of HDPE liner in CS Pipe which is under designed to inject high pressure water. Objective is to calculate the safe wall thickness of HDPE.Regards Hi Nick,I have seen various discussion from you on this topic. I am quite beginner in this topic. I appreciate if a detail discussion on how the stresses can be calculated of HDPE liner in CS Pipe which is under designed to inject high pressure water. Objective is to calculate the safe wall thickness of HDPE.Regards http://www.composite-agency.com/messages/5216.html 16 Aug 2010 09:57:21 GMT Wajid http://www.composite-agency.com/messages/5216.html Dear All,In 2007 we have done some pilot Electrochemical Impedance Spectroscopic (EIS) measurements and Electrochemical Noise Measurements (ENM) for determining the diffusion coefficient of water in several thin films. The results were indeed not so good, and DVS weight measurements appeared to be necessary. We do not believe that any substantial or fundamental has happened since then, apart from a database that has been developed to cover all the materials (read: variations). Moreover, for some reason, a standard has been developed (NEN-EN-ISO 16773-1:2007 en. Verven en vernissen - Dear All,In 2007 we have done some pilot Electrochemical Impedance Spectroscopic (EIS) measurements and Electrochemical Noise Measurements (ENM) for determining the diffusion coefficient of water in several thin films. The results were indeed not so good, and DVS weight measurements appeared to be necessary. We do not believe that any substantial or fundamental has happened since then, apart from a database that has been developed to cover all the materials (read: variations). Moreover, for some reason, a standard has been developed (NEN-EN-ISO 16773-1:2007 en. Verven en vernissen - http://www.composite-agency.com/messages/5308.html 13 Jul 2010 15:00:27 GMT Composite Agency http://www.composite-agency.com/messages/5308.html Electrical Impedance for Coating residual lifetime is a project in which the wish has been the father to the thought. The data generated by the method is not robust and hardly reproducable. It gives many headaches to derive a single water diffusion coefficient from the method, and the Fickian equilibrium is not attained explicitelyy. Hence, it can not deal with cyclic environmental moisture variations, and the programmed baseline will be dependent on the material (of which the diffusion coefficient could have been measured using the mass uptake method, or the software on this site anyway), it Electrical Impedance for Coating residual lifetime is a project in which the wish has been the father to the thought. The data generated by the method is not robust and hardly reproducable. It gives many headaches to derive a single water diffusion coefficient from the method, and the Fickian equilibrium is not attained explicitelyy. Hence, it can not deal with cyclic environmental moisture variations, and the programmed baseline will be dependent on the material (of which the diffusion coefficient could have been measured using the mass uptake method, or the software on this site anyway), it http://www.composite-agency.com/messages/5308.html 13 Jul 2010 13:47:27 GMT Sylvia http://www.composite-agency.com/messages/5308.html Dear All:Thanks for the CheFEM part on this website. The prediction of fluid-coating interactions is still of major importance in many industrial applications. So, for selection of the proper materials, a software tool like CheFEM is very helpful. But can the software also be used to predict the residual lifetime of an industrial coating applied in real life circumstances (assuming that the processing environment was not ideally)?Reason for asking is that recently I read an article in which they state that Electrical Impedance Spectroscopy (EIS) can be used for measuring the residual lifetime Dear All:Thanks for the CheFEM part on this website. The prediction of fluid-coating interactions is still of major importance in many industrial applications. So, for selection of the proper materials, a software tool like CheFEM is very helpful. But can the software also be used to predict the residual lifetime of an industrial coating applied in real life circumstances (assuming that the processing environment was not ideally)?Reason for asking is that recently I read an article in which they state that Electrical Impedance Spectroscopy (EIS) can be used for measuring the residual lifetime http://www.composite-agency.com/messages/5308.html 12 Jul 2010 16:19:50 GMT Charles Fisher http://www.composite-agency.com/messages/5308.html Dear Sandra,Below some diffusion, solubility, permeability coefficients in some membranes at ambient conditions (25 degrees Celsius ant atmospheiric pressure), no moisture present:General Rubber 1000, 12, 120Butyl rubber 49, 4.4, 2.1 Polyurehtane soft 408, 5.6, 23 Polyurethane hard 88, 7.9, 4.9 Polyvinylchloride soft 420, 10, 42 Polyvinylchloride hard 140, 5.2, 7.3 Polyamide Supronyl 6.1, 3.4, 0.2 Plexi Glas (PMMA) 6.2, 8.2, 0.5 Legend: Material, Diffusivity [1E-10 cm2/s], Solubility[-], Permeability[1E-8 cm2/s].The Radon diffusion through Epoxy resin is very dependent on the type of Epoxy ( Dear Sandra,Below some diffusion, solubility, permeability coefficients in some membranes at ambient conditions (25 degrees Celsius ant atmospheiric pressure), no moisture present:General Rubber 1000, 12, 120Butyl rubber 49, 4.4, 2.1 Polyurehtane soft 408, 5.6, 23 Polyurethane hard 88, 7.9, 4.9 Polyvinylchloride soft 420, 10, 42 Polyvinylchloride hard 140, 5.2, 7.3 Polyamide Supronyl 6.1, 3.4, 0.2 Plexi Glas (PMMA) 6.2, 8.2, 0.5 Legend: Material, Diffusivity [1E-10 cm2/s], Solubility[-], Permeability[1E-8 cm2/s].The Radon diffusion through Epoxy resin is very dependent on the type of Epoxy ( http://www.composite-agency.com/messages/5306.html 07 Jul 2010 16:59:50 GMT Composite Agency http://www.composite-agency.com/messages/5306.html Hi,Does someone know the permeation rate of Radon through cast and glass reinforced resins (e.g. polyester, ve resin, epoxy resin) and thermoplastic materials (polyamide, polyvinylchloride, polypropylene) in the presence of Water (relative humidity 80-100%). What is the solubility (parameter) of Radon, Xenon and Krypton in these plastics?Best Regards,Sandra Hi,Does someone know the permeation rate of Radon through cast and glass reinforced resins (e.g. polyester, ve resin, epoxy resin) and thermoplastic materials (polyamide, polyvinylchloride, polypropylene) in the presence of Water (relative humidity 80-100%). What is the solubility (parameter) of Radon, Xenon and Krypton in these plastics?Best Regards,Sandra http://www.composite-agency.com/messages/5306.html 09 Jun 2010 12:21:39 GMT Sandra http://www.composite-agency.com/messages/5306.html Multiphysics simulation is one of the fastest growing research field in industrial engineering. This conference will concentrate on some aspects of this emerging research field. The contributed papers will show new engineering processes and demonstrate their practicability in real engineering cases. Enhenced numerical algorithms, new software solutions, advanced modelling procedures, and engineering guidelines will be presented by more 70 authors from research and industry.Organized by Fraunhofer Allianz Multiphysics simulation is one of the fastest growing research field in industrial engineering. This conference will concentrate on some aspects of this emerging research field. The contributed papers will show new engineering processes and demonstrate their practicability in real engineering cases. Enhenced numerical algorithms, new software solutions, advanced modelling procedures, and engineering guidelines will be presented by more 70 authors from research and industry.Organized by Fraunhofer Allianz http://www.composite-agency.com/news.htm#5306 28 May 2010 10:42:26 GMT Composite Agency http://www.composite-agency.com/news.htm#5306 John,Thanks for your kind feedback.According to the most reputable models on ageing, physical ageing (including creep and free volume contraction of polymers, for example epoxy, below the glass transition) does not influence the interfacial toughness (expressed in Joule per square meter) if determined in the correct manner. This has been extracted from very rigorous experiments and modelling on fibre pull-out. However, chemical ageing resulting in matrix plasticizing, chemical degradation of an interfacial adhesive/sizings and matrix material expansion by mass uptake and thermal, certainly John,Thanks for your kind feedback.According to the most reputable models on ageing, physical ageing (including creep and free volume contraction of polymers, for example epoxy, below the glass transition) does not influence the interfacial toughness (expressed in Joule per square meter) if determined in the correct manner. This has been extracted from very rigorous experiments and modelling on fibre pull-out. However, chemical ageing resulting in matrix plasticizing, chemical degradation of an interfacial adhesive/sizings and matrix material expansion by mass uptake and thermal, certainly http://www.composite-agency.com/messages/5303.html 17 May 2010 16:07:54 GMT Composite Agency http://www.composite-agency.com/messages/5303.html Just found some additional info on Graphene based Epoxy composites, the outcome are not bad and this is an understatement. Here it goes:Graphene equal to 0.1 percent of the weight of the composite boosted the strength and the stiffness of the material to the same degree as adding carbon nanotubes equal to 1 percent of the weight of the composite. This gain, on the measure of one order of magnitude, highlights the promise of graphene, Koratkar said. The graphene fillers also boosted the composite’s resistance to fatigue crack propagation by nearly two orders of magnitude, compared to the Just found some additional info on Graphene based Epoxy composites, the outcome are not bad and this is an understatement. Here it goes:Graphene equal to 0.1 percent of the weight of the composite boosted the strength and the stiffness of the material to the same degree as adding carbon nanotubes equal to 1 percent of the weight of the composite. This gain, on the measure of one order of magnitude, highlights the promise of graphene, Koratkar said. The graphene fillers also boosted the composite’s resistance to fatigue crack propagation by nearly two orders of magnitude, compared to the http://www.composite-agency.com/messages/5303.html 12 May 2010 12:27:20 GMT John Cllarck http://www.composite-agency.com/messages/5303.html Thanks for the nice website, and CheFEM. I like the inclusion of rigorious FEM chemical thermodynamics in the study and simulation of composite materials! My question is on physical and chemical ageing. As we all know ageing relaxes internal stresses, no matter generated by mechanical loading, residual thermal stresses or a diffusing permeant. But, will this ageing influence the interfacial toughness of for example, an epoxy composite reinforced with Graphene? Let us suppose that the interface is not weakened by chemical reaction and/or plastification.I suppose this is included in CheFEM Thanks for the nice website, and CheFEM. I like the inclusion of rigorious FEM chemical thermodynamics in the study and simulation of composite materials! My question is on physical and chemical ageing. As we all know ageing relaxes internal stresses, no matter generated by mechanical loading, residual thermal stresses or a diffusing permeant. But, will this ageing influence the interfacial toughness of for example, an epoxy composite reinforced with Graphene? Let us suppose that the interface is not weakened by chemical reaction and/or plastification.I suppose this is included in CheFEM http://www.composite-agency.com/messages/5303.html 12 May 2010 11:07:37 GMT John Clarck http://www.composite-agency.com/messages/5303.html Graphene is one of the most promising nano material in modern material science. One atomic layer of Graphene is completely diffusion and permeation tight. Moreover, the tensile strength of Graphene is 20 times stronger than steel. And Graphene has some other very interesting chemical-physical features.Since application of Graphene in packaging materials, coating and composites, etc. is nearby, simulation and analysis of Graphene based materials in real-life circumstances becomes more and more important. In this perspective, we are happy to inform you that -as expected - a recent published Graphene is one of the most promising nano material in modern material science. One atomic layer of Graphene is completely diffusion and permeation tight. Moreover, the tensile strength of Graphene is 20 times stronger than steel. And Graphene has some other very interesting chemical-physical features.Since application of Graphene in packaging materials, coating and composites, etc. is nearby, simulation and analysis of Graphene based materials in real-life circumstances becomes more and more important. In this perspective, we are happy to inform you that -as expected - a recent published http://www.composite-agency.com/news.htm#5303 11 May 2010 13:56:00 GMT Composite Agency http://www.composite-agency.com/news.htm#5303 Leading Companies Reduce Product Cost by 6% While Competitors See Cost IncreasesBOSTON, MA--(Marketwire - May 5, 2010) - Aberdeen Group, a Harte-Hanks Company (NYSE: HHS) today released a new research study titled Cost Saving Strategies for Engineering: Using Simulation to Make Better Decisions. The study uncovers the most successful ways companies are taking cost out of their product designs and the role simulation plays in this. The most profitable companies are 70% more likely than competitors to implement a 'get it right the first time' strategy, as well as analyze product behavior Leading Companies Reduce Product Cost by 6% While Competitors See Cost IncreasesBOSTON, MA--(Marketwire - May 5, 2010) - Aberdeen Group, a Harte-Hanks Company (NYSE: HHS) today released a new research study titled Cost Saving Strategies for Engineering: Using Simulation to Make Better Decisions. The study uncovers the most successful ways companies are taking cost out of their product designs and the role simulation plays in this. The most profitable companies are 70% more likely than competitors to implement a 'get it right the first time' strategy, as well as analyze product behavior http://www.composite-agency.com/news.htm#5303 07 May 2010 12:49:55 GMT Composite Agency http://www.composite-agency.com/news.htm#5303