How to solve this "zero or negative yield stress encountered. nonlinear analysis cannot proceed. this issue may occur if the hardening parameter H is negative"?

Alberto CAMPUZANO
Alberto CAMPUZANO Altair Community Member
edited January 2024 in Community Q&A

Good morning dear all.

Look I am doing a simple three point bending of a sandwich panel (skin, core, skin) the core with the skin are attached using FREEZE, the material used is an isotropic one, using TABLES1, I used the curved with CSV format. I set my density, young modulus, and Poisson ratio, I DID NOT SET THE YIELD STRESS, because I have curve right? (I am doing nonlinear analysis, nonlinear static)

Well, when I start the simulation, it seems everything goes right and converging, until this error appears.

"zero or negative yield stress encountered. nonlinear analysis cannot proceed. this issue may occur if the hardening parameter H is negative".

How to solve this?

Thanks in advance

 

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Answers

  • loistf
    loistf Altair Community Member
    edited January 2024

    Hi Alberto. Have you tried running the same thing with a different material or a different curve? (ideally, some monotonically non-decreasing function). 

    Is the result any different?

  • WagnerFEA
    WagnerFEA Altair Community Member

    This error can be corrected by placing a value for the yield stress into the LIMIT1 field on the material card. I think the yield value is still required, even if you have a curve, to determine the plastic strain versus the elastic strain.