Simple plastics modeling software

[blueandwhiteg3]

I'm finding that I am working with a few different projects involving plastics, particularly transparent plastics, and need to model their physical parameters. I suppose there might be a bit of glass or metal in there too, but it's mostly about the plastics.

The designs aren't so complex that I need software to assist in actually generating the design. But the problem is optimizing the designs (specifically material thicknesses and support/reinforcement structures) so that they tolerate the loads reliably, but also aren't overbuilt in terms of materials.

I have hard values for the stresses, material strengths, etc., but you reach a certain point, where mechanical properties and a calculator just don't cut it anymore. How much will this bulge under that much pressure? When will we start to hit crazing problems with acrylic here?

Do you guys have any suggestions for software that might be fairly simple to use for a beginner, yet provide some of this modeling?

It would be even cooler if I could model optical and thermal properties.. but that maybe an entirely new door I don't want to open yet!

 

[patprimmer]

The material suppliers should be able to help with data & safety factors.

DuPont, Sumitomo, Bayer, Rhom Domstadt, Sabic are a few.

This lik should give you a start to finding current suppliers.

http://en.wikipedia.org/wiki/Acrylic_glass

Regards
Pat
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[blueandwhiteg3]

I have a lot of data on the actual materials. Suppliers, matweb.com, etc. and many other sources furnish a lot of data.

The problem becomes modeling the stresses. The designs I'm looking at never have situations where it is strictly compressive or tensile or whatever single property. It's usually some combination of different stresses, angles, etc.

Then on top of that, you want to model the kind of a flex you'd have under the given load. Yes, I could probably model that with a lot of work, but when you have a mix of tensile load and flexural load, it gets really convoluted to solve.

So, bottom line, I'm looking for specific suggestions on modeling software here.

 

[CoryPad]

Modeling mechanical, optical and thermal properties of polymeric materials is extremely challenging. There won't be simple software solutions for these - you will need complex ones. Best to start with the large code makers - ANSYS, LS DYNA, ABAQUS, NASTRAN, N CODE, ALGOR, etc.

Regards,

Cory

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[Demon3]

I see your problem, the modelling is complex in the real part geometry under load. However, the reason that modeling software will fail is that polymers don't behave like metal or glass. The polymers flow and are not elastic like other materials. To model polymers properly is possible but not with any kind of simple software and you need mechanical data far in advance of the usual modulus, yield strength etc.. You need the time dependent data and because that's not published, you have to measure it yourself. I have seen excellent modeling that gives accurate results (even under impact conditions) done by Borealis (polyolefins supplier).


Chris DeArmitt

 

[blueandwhiteg3]

Hmm. It seems like every simple question ends up anything but!

If I narrowed my inquiry down to the performance characteristics of polycarbonate sheets under pressure, would there be a specific direction in which to look?

 

[CoryPad]

ABAQUS by Simulia or Nastran by MSC.

Regards,

Cory

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[NunoH]

Hi guys.

I don't know any straightforward Finite Element Analysis software. Or cheap for that matter. They generally cost tens of dollars.
Generally it would be convenient to have an expert, unless the design is quite basic. But for this, you should be able to hit it off with a spreadsheet or a program such as MathCAD (easier for auditing purposes).
I don't know the amount of work you do, but it might be all in all, cheaper and easier to subcontract the final optimisation. or to bring in someone that knows about finite element modelling, particularly applied to non-linear materials.

Involving optical properties it's a whole new game...Too complicated.
Thermal properties is easier, depending on wthat you want to achieve.

I am not sure about user-friendliness, but COSMOS (Dassault) might be a bit straight forward and should work together with Solidworks.




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