Actually, you don’t need subroutines to do this. What’s more it can all be done in CAE:
- in material editor select Elastic behavior, change Number of field variables to 1 and specify Youngs’s modulus and Poisson’s ratio pairs for each value of field variable (set Field 1 as 0,1,2,...).
- define amplitude, type time values in the first column while in the Amplitude column put corresponding values of Field 1 from the previous step (0,1,2,...). So for example this pair: Time=6, Amplitude=2 means that at t=6 Abaqus will use Young’s modulus assigned to Field=2.
- in the Load module select Create Predefined Field, choose analysis step, Other and Field. Select whole model. Leave Field variable number as 1, specify magnitude of 1 and select amplitude created in the previous step.
If you don’t use CAE, here’s keyword version:
But it should be *Elastic, dependencies=1