2维平面应变+各项同性+J2流动+自定义屈服强度等效塑性应变关系+欧拉后推径向返回-ABAQUS UMAT

等效线性粘弹性模型UMAT子程序编写，用粘弹性Kelvin模型来反映土体在周期荷载下的滞回性。(The UMAT subprogram of the equivalent linear viscoelastic model is written, and the viscoelastic Kelvin model is used to reflect the hysteretic behavior of the soil under periodic load.)

等效粘弹性模型UMAT子程序，适合准备编程学习的朋友(Equivalent viscoelastic model -- UMAT subroutine)