Home Work:

1. Explain in detail the following failure theories.

1. Hoffman Theory

2. Tsai-Wu Theory

2. What is the difference between Tsai-Hill and Hoffman theory?

3. What are the key features of the Tsai-Wu theory?

4. What are the different methods to find the strength parameter  in Tsai-Wu theory?

5. Explain the methods to find the strength parameter  in Tsai-Wu theory.

6. A ply of AS4/3506-1 material with  fibre orientation is in the planar state of stress. The strains are . Check that whether lamina will fail if a) Hoffman theory b) Tsai-Wu theory is used.

7. Find the maximum value of  if a state of stress of   and  is applied to the  lamina of AS4/3506-1 material using a) Hoffman theory b) Tsai-Wu theory.