I am a PhD student in China University of geosciences. Recently, I have been working on the simulation of a pile-soil interaction with Abaqus. I simulate the sand with the sand hypoplasticity model provided by Prof. Masin.
However, When I call the umat.for file, an error like “No vumat subroutine was supplied for the user material named: material-1” always appears.
I did not find a solution to this error on the Internet, so I ask for help. Any suggestion or comment will be appreciated.