振動分析中，ABAQUS 施加正弦位移，為什么會出現位移突變？

warning：

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

具體問題：將RP與圖中節點耦合，在RP上施加圖示位移，按正弦規律加載橫向位移，為什么會出現位移突變這種warning呢