Hi! I'm modeling a composite and doing a coupled thermal displacement analysis, which is why I decided to use Engineering Constants, however when I update the results I get the following error:
*** ERROR # 1551 ***
for material id = 1 referenced from property id = 1.
Material coefficients Gij on MAT9 card produce material matrix with negative eigenvalues. This violates material stability conditions.
The material properties I used are these:
The G12 I know is correct, I read that G12 and G13 are the same, however, for G23 I calculated the value with the following formula : E22/2(1+V23). Is this correct? If now what can I do?
