1. BI-AXIAL STRESS AND MSS THEORY
FAILURE BOUNDARIES
PART 6B
SUMMARY

2. MAXIMUM SHEAR STRESS Statement of the theory
When Yielding occurs in any material
The maximum shear stress at the point of failure
Equals or Exceeds
The maximum shear stress when yielding occurs
In the tension test specimen.

3. PRINCIPAL STRESSES IN BIAXIAL STRESS SITUATION
In plane stress situation, the principal stresses are given by the expression

4. BIAXIAL STRESS SITUATION
For plane (bi-axial) stress situation
Third principal stress is zero
The extreme values of shear stress are then expressed as:

5. UNI-AXIAL STRESS SITUATION
Simple tension is an example
When yielding occurs in tension test specimen

6. MOHR’S CIRCLE DIAGRAMS

7. MAXIMUM SHEAR STRESS THEORY IN BI-AXIAL STRESS
Principal stresses: of OPPOSITE sign

8. PRINCIPAL STRESSES: of OPPOSITE sign

9. MAXIMUM SHEAR STRESS THEORY IN BI-AXIAL STRESS
Principal stresses: of SAME sign

10. PRINCIPAL STRESSES: of SAME sign
Expression for Failure boundaries

11. MOHR’S CIRCLE DIAGRAMS BI-AXIAL STRESS

12. MAXIMUM SHEAR STRESS THEORY IN BI-AXIAL STRESS
Failure boundaries in bi-axial stress

13. MAXIMUM SHEAR STRESS THEORY IN BI-AXIAL STRESS
Failure boundaries in bi-axial stress