SPH方法模拟单轴压缩压头和土体为什么没有竖向位移？ 50

本人小白，学习用SPH方法模拟单轴压缩试验，压头底座和圆环都采用刚体，土体采用SPH颗粒进行分析。仅对底座和圆环设置了固定的边界条件，压头仅允许竖向位移，土体颗粒无边界条件，运行完后得到如下警告:

OP=NEW on *CONTACT is ignored when the general contact definition is specified as model data.

The option *boundary,type=displacement has been used; check status file between steps for warnings on any jumps prescribed across the steps in displacement values of translational dof. For rotational dof make sure that there are no such jumps. All jumps in displacements across steps are ignored

以下上传inp文件，新手小白求大佬解答，不甚感激！！

SPH.zip