epoxy compression stiffness

[mazutar]

Hello, can anyone explain me how to determine compression stiffness?. Im modeling a epoxy as a gap element in Femap.
On catalog of epoxy manufacturer i found out that compression strength of epoxy is 130 MPa but Femap needs compression stiffness (N/mm).
so how to determine?

 

[GruntCZ]

Hello,
you won't. To calculate stiffness, you will need Young's modulus, and cross section of solving part. If you are able to find the solution for your situation then you have to calculate stiffness accordingly to analytic solution of simplified model. For example, for simple tension / compression of simple beam is k=(E*A)/l.

k.. Stiffness
E.. Young's modulus
A.. Area of cross section
l.. length of beam

This solution is correct, only for linear material. For non-linear materials, stiffness isn't one number, but is deformation - dependent. And the solution is much more complicated.

I hope it will help to you.