How to model a gasket compression test in LS-DYNA?

[mohamed amine zaari (Iraaz.official)]

Hello everyone,

I would like to model the compression of a gasket placed between two steel parts in LS-DYNA. I have the experimental compression curve from a physical test (displacement vs stress), and I’m trying to understand the best way to reproduce this behavior in LS-DYNA.

I saw that there are several material cards related to gaskets or cohesive-type behavior, but I’m not sure which one is appropriate for a uniaxial compression gasket.

My questions are:

Which material model should I use to input a compression curve (stress vs strain or displacement)?

Which section type should I choose for a gasket modeled as a solid?

Should I use one single solid element through the thickness, or is it recommended to have multiple elements?

If you have a tutorial or example showing how to model a gasket compression in LS-DYNA, it would be very helpful.

Thank you in advance for your guidance! :)
Amine

[Selçuk Başdemir]

Hi Amine,

I think you are trying to simulate a rubber-like gasket. Then a rubber or foam material models will be appropriate. Lets say you choose Ogden Model to model your gasket. You need to fit your experimental data and calibrate model parameters. However, I do not suggest to make calibration with only compression data, uniaxial and biaxial test may ve needed for better calibration. Do you have confined compression data? Since uniaxial compression is not a homogeneous test ( due to bulging effect), you need to consider load-displacement instead of stress-displacement or you may conduct confined compression tests. If you have only compression data and no chance for other experiments, then try Yeoh or Mooney-Rivlin model at first since these models have less parameters to calibrate rather than Ogden.

You may also see the attached paper for further reference.

8 Aralık 2025 Pazartesi tarihinde saat 22:31:42 UTC+3 itibarıyla medz...@gmail.com şunları yazdı:

[mohamed amine zaari (Iraaz.official)]

Hi   şunları Thanks for the information.

Since I only have compression test data in the form of displacement vs stress, I was wondering if MAT_COHESIVE_GASKET might actually be more appropriate for my situation.

My gasket is PTFE, working only in pure compression between two steel parts, and I am mainly trying to reproduce its nonlinear compression curve.

From the LS-DYNA manual, MAT_COHESIVE_GASKET seems to allow defining the gasket response directly from a tabulated force–displacement curve or similar input.

Given that I don’t have tension or biaxial data (only compression), and that the material never works in tension in my application:

 Would MAT_COHESIVE_GASKET be the most suitable choice to model a compression-only gasket based on test data?

Any guidance or experience with this material model would be greatly appreciated.

Thanks!

Amine