On 09 Aug 2008 at 22:07:11 Gianfranco posts:
Dear All:

I want to programme a simulation programme for heat transfer in a metal pipeline with an organic coating on the inside. With this regard I have two questions: - what programming language can I choose best? and - do I solve best with finite element analysis or finite difference methodology? What are the advantages/disadvantages of these mathematical simulation / estimation methods for temperature gradient and flux calculations.

Thank you all in advance.

Best
Gianfranco
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On May 29, 2008 at 16:34:36 composite agency posts:
All these state-of-the-art programmes - based on finite element analysis (FEA) - are very useful for mechanical design calculations. They are oriented on mechanical calculations on tensile, compressive, hoop, buckle stress of metals, polymers and composite materials exposed to an external or intrinsic design load. Moreover they are able to include delamination, fiber/matrix failure, fracture energies and temperature effects. They have been used for simulation of glass fibre laminates, carbon fibre laminate, metal to fibre laminates, for advanced applications (such as aerospace: Airbus A380, Boeing Carbon Epoxy Fibre, Joint Strike Fighter - JSF, wind mill blade, rotor blades).

External loads, intrinsic loads and temperature are one of the major design factors of mechanical polymers and composite (including laminate and multilayer materials) simulations.

Let us list them:
- external loads
- internal loads
- temperature (stress)

In real life, there is also exposure to chemicals. Loading by chemicals results in surface corrosion, chemical degradation and permeation. These processes may adjust the mechanical properties to a significant extent. Moreover, selective loss of chemicals from containments such as bottles, medical packages, electronics overmold packaging or pipelines, may be a problem. The formulation of combinations of different materials, such as metals, fibres (carbon, kevlar, glass) and plastics, may provide an appropriate composite or laminate solution. The physical-chemical properties of these materials are rather complex. At the same time rigorous prediction of the material behaviour, service, shelf and maintenance life are of major importance. This is of course also an issue, think of a new coating or anti fouling for your yacht, but since these advanced composite materials require high capital investments and as the are applied in severe circumstances, appropriate prediction of lifetime is even more vital.

Hence chemical surface corrosion, chemical degradation of polymer chains, permeability with regard to equipment exposed to chemicals like liquids like water, acids, alkaline solutions, solvents like BTEX, oil, diesel, LNG, LPG, gasoline, crude and gases, like hydrogen, oxygen, nitrogen, carbon dioxide, argon, chlorine, bromine etc., can not be ignored. Prediction of these phenomena requires expertise and experience. Composite Agency developed the Instationary Diffusion Corrosion Simulator for Advanced Composites (IDC - SAC) which is based on chemical physical simulation and the developed library of experimental key figures (such as free volume characteristics of a polymer). This tool allows rigorous determination of plastic and reinforced plastics properties in real life industrial applications. This is not limited to chemical processing applications, but includes as stated civil equipment - potable water pipelines, polymer to concrete, aluminium to polymers, aerospace, electronic packaging applications. Please check the case studies and tables section on this website for more information on how we guide chemical resistance. The information includes cases on glass fibre epoxy, high density polyethylene, polyurethane, vinyl ester, poly phenylene sulphide, poly ether etherketone, polyamide and fluoro polymers (ptfe, pvdf) exposed to bromine, chlorine, hydrofluoric, sulphuric, hydroclhloric acid, gasoline etc.

Composite Agency

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On 04/17/2008 rodney posts: Also take a look at ANSYS Multiphysics Finite Element Software.

They state that: "ANSYS Multiphysics solution enable engineering people and people in charge of design, to rigorously simulate the interaction of fluid flow dynamics, acoustics and electromagnetic interaction, structural mechanics by finite element simulations, all within a single software product.".

Their online video presentation plainly confirms the previous statements!

In several cases, especially chemical resistance and corrosion in combination with permeation and/or UV, is a significant aspect of the material decision. For example, when designing in FRP, corrosion resistance is a specific material design consideration. Then additional info, such as chemical resistance guides, type of processing, corrosion and diffusion rates are of importance.

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