求助！！！

出现以下问题（我从message里面复制过来的）：
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
*** WARNING plasticity algorithm did not converge for MAT36
for 1 elements
node # 39934 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39935 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39936 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39937 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39938 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39939 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39940 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39941 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39942 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39943 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39944 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39945 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39946 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39947 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39970 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39971 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39972 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39973 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39974 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39975 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39976 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39977 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39978 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39979 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39980 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39981 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39984 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39985 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39986 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
node # 39987 has out-of-range velocities
x-velocity= NaN
y-velocity= NaN
z-velocity= NaN
7883 t 8.5126E-03 dt 1.08E-06 write d3plot file
7883 t 8.5126E-03 dt 1.08E-06 write d3plot file
E r r o r t e r m i n a t i o n
我采取的措施是修改了时间步长，把网格再检查了一遍，可是还是出现以上问题，请哪位牛人指点一下该如何修改