Explicit Dynamics- Single Fiber Test does not reach ultimate stress

[sghod17]

Hi, I am working on a simple single fiber "tensile test". One side of the fiber is fixed and the other is applied a velocity boundary condition. I am trying to conduct it in a quasi-static analysis. Therefore, I have assessed a ton of velocities (especially slow velocities within 1% of the wave propagation speed of the material). For the velocities that have the stress flow throughout the body, the stress stops increasing well below the failure criterion. I have even tried to vary the static damping coefficient. The material is defined with a multilinear isotropic hardening plasiticity law and plastic strain failure criterion. Am I missing something or have I setup the problem wrong somehow?

Thanks any help is appreciated

 

[Mustaine3]

Are you sure that you didn't reached the last stress you've entered within the plasticity data? Check the mises stress at the integration points.

You're running the simulation with geometric nonlinearities?

 

[sghod17]

I have been working on the issue since I posted my question. And i did not realize that the data you insert for plasticity is not necessarily the exact data that you get from a uniaxial tensile test. I have been working to iteratively change the data to match my experimental results in uniaxial tension then I will move to my central focus (which is a problem with geometric nonlinearities and large deformations).