Single place to enter compressive strength for a material?

[jeff.castle]

My students and I are doing some structural load tests using EPS foam. I have basic properties of our material: tensile strength, compressive strength, density, some thermal stuff.

Our material properties don't match up with the default EPS settings in Fusion, so we're updating them. I don't see a field for compressive strength though. Does one exist? My fear is that instead, we'll have to define yield strength and a bunch of other properties we don't have values for. Thanks

[John_Holtz]

Hi @jeff.castle Welcome to the Fusion forum.

Another question to ask about your EPS foam is whether it behaves the same as a metal material.

• A metal has a region of stress-strain where it is linear and elastic (known as the modulus of elasticity, or Young's modulus). Double the load within the elastic portion, and the displacements are double. Remove the load, and the part returns to 0 displacement. Above the elastic limit (known as the yield strength), the part begins to deviate from the linear relationship. Also, when you remove the load, the part does not return to 0 displacement; it has a permanent deformation (known as "plastic" deformation). Some metals, and the material response currently programmed in Fusion, behave the same in compression and tension, so you only need to enter the tension branch of the stress-strain curve. If your foam behaves this way, you can use Fusion.
• If your foam does not behave the same as described above, then you cannot use Fusion. For example, a material could be elastic but not linear: doubling the load may not create twice the displacement, but the part returns to 0 displacement when the load is removed. (This is typical behavior for rubber and hyperfoam material.)

You may want to give us more details about what you want from the analysis. For example, do you need to know that it will crush (compression) or break (tension), or do you need to know what happens after it crushes/breaks? If you only need to know whether it will crush/break, and if the stress-strain behavior is linear to that point, then you can perform the analysis and check if the stress results exceed the allowable.