If you need linear elastic or Mises plastic UMAT and related CAE models please visit this link:
https://www.engssoft.com/elastic-plas...

This video is the first part of a series, which help you step by step, to write your own first plastic UMAT subroutine. In this video basics of Mises plasticity are explained. In the next video the algorithm which is used to solve Mises equations is depicted, and in the last video related UMAT subroutine is described. In this video can find out:
Introduction 00:00
Understanding stress-strain curve, elastic and plastic regions 1:00
Plastic hardening 2:05
Mises effective stress 2:49
Mises effective plastic strain 7:07
Mises yield criterion and its characteristics 8:25
Normality hypothesis 10:32
Consistency condition 12:22