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I have the same problem.
With quad or 9_4_quadup elements, when i update material stage from 0 to 1, i have the error "Jacobian matrix is singular".

Hi. I create a simple model with Drucker Prager material and quad elements but it didn't converge at all even in static analysis. I try my model with other materials like PDMY and it runs without any problem. I also change any parameters of this material but in didn't converge. What is wrong with th...

Thanks for your reply.
So is there any other material that can be used for modeling flow liquefaction?

The mechanism of liquefaction in PressureDependMultiYield material is cyclic mobility (non-flow liquefaction) but in the manual there are 5 optional parameters in the PDMY material command based on the work of Li and Wang to define critical state line for modeling flow liquefaction. I am modeling lo...