ansys混凝土非线性分析

混凝土应力应变输入以后，solve时出现“For material 1 at temperature 0, the initial slope of the stress-strain curve based on the TB,MISO table ( 4.446E+09 ) is less than EX ( 2.9635E+10 ).”错误，怎么处理，该曲线是试验测得的。分步加载荷步之后，分别write ls files，但是Slove时，如果单独读取其中任何一个载荷步，用current ls命令可以计算并收敛；如果使用from ls files就会出现错误“The value of UX at node 18 is 17061651.8. It is greater than the current limit of 1000000. This generally indicates rigid body motion as a result of an unconstrained model. Verify that your model is properly constrained.”这是什么原因，怎么处理？如果采用位移控制，分步加载，也是单独读取其中任何一步都能计算并且收敛，但试用from ls files后，就会不断warning：“There are 1 small equation solver pivot terms.”虽然可计算，并收敛，但结果图形很不理想。