材料设置非线性以后求解出现警告

weixuesheng001

材料设置常物性的时候正常，若设置非线性时就会有如下警告，这个怎么解决：
*** WARNING ***                         CP =      65.750   TIME= 21:36:49
The program chosen initial timestep/load-factor is arbitrary.  It is   
necessary for the user to supply a suitable initial                     
timestep/load-factor through the NSUB or DELTIM command for            
convergence and overall efficiency.                                    
*** WARNING ***                         CP =      73.234   TIME= 21:37:02
Material property KXX of material 1 of element 7801 is evaluated at a   
temperature of 0, which is below the supplied temperature range.        
Temperature range checking terminates.