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Problems of error in the plasticity hardening model: Lamda non positive for plastic points

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Hello every experts and comsol users, I made a simulation of laser beam welding and added a temperature dependent plasticity. When the generated stress reaches the initial yield stress, I get the error "Error in elPlastic element. - Detail: Lambda non positive for plastic point". I have seen the same problems of others, but the problems are not solved. I have tried to decrease the tolerance, the size of the meshes and the time step, but it does not work. Are there any problems in my temperature dependent yield curving in attachment? I simply did the same as the example: The temperature of simulation is about 1000K and the Laser worded in the first 1.5 seconds and the temperature gradients are very big.

Any help would be appreciated. Thanks in advance.

0 Replies Last Post 19 Mar 2019, 13:15 GMT-4
COMSOL Moderator

Hello Shiyu Li

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