How to Address and Interpret Negative Eigenvalues in ABAQUS System Matrices?

06 September 2023 0 7K Report

I'm Conducting an ABAQUS Dynamic Implicit Simulation of a Knee Joint represented with Rigid Bones, 3D deformable Cartilage, and Menisci with ligament modeled using nonlinear 1D spring elements.

I have encountered several Warnings: 'The System Matrix Has Negative Eigenvalues,' Leading to Simulation Abortion. Seeking Guidance and Solutions. Attached is an Image of the Warnings and Model .inp File for Reference.

Your Expertise is Highly Appreciated.

Thank You!

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