Module 6: Failure and Damage
  Lecture 23: Macroscopic Failure Theories
 


Various Criteria in Tensor Polynomial Form:
           
In this section we express the criteria/theory we have seen in tensor polynomial form as expressed by Equation (6.35).

1) Maximum Stress Theory:
           
The maximum stress theory can be given in tensor polynomial form as

(6.75)

Thus, the strength parameters corresponding to tensor polynomial criterion as in Equation (6.35) for maximum stress theory are:

(6.76)

           
The remaining strength parameters are zero. In above equation the higher order terms are neglected.

2) Tsai-Hill Theory:
           
Comparing Equation (6.20) with Equation (6.35), we get


(6.77)

3) Hoffman Theory:
           
Comparing Equation (6.33) and Equation (6.35), we get


(6.78)