Strength Failure Criteria — Part 2 — Lesson 2

This lesson covers the strength failure theories of lamina, focusing on the differences between isotropic and orthotropic materials. It delves into the importance of stresses in the material direction due to the strengths of orthotropic lamina being defined with reference to the material axis. The lesson also discusses independent non-interactive theories where each strength is compared independently to assess failure or safety. It further explores interactive theories where the combined effects of the strengths are taken into account. The lesson concludes with a comparison of different failure theories, highlighting that the Tsai-Wu failure theory provides a better prediction for materials like glass epoxy.

Video Highlights

02:14 - Discussion on independent non-interactive theories
06:19 - Maximum Strain Failure Theory
15:21 - Exploration of interactive theories
31:51 - Tsai-Hill Failure Theory
36:31 - Hoffman Failure Theory
40:44 - Comparison of different failure theories
45:16 - Tsai-Wu Failure Theory

Key Takeaways

- The strength failure theories of lamina are an extension of the same in isotropic material.
- In orthotropic lamina, the strengths and stiffnesses are direction dependent.
- Independent non-interactive theories compare each strength independently to assess failure or safety.
- Interactive theories take into account the combined effects of the strengths.
- The Tsai-Wu failure theory provides a better prediction for materials like glass epoxy.