Failure of Laminates — Lesson 1

This lesson covers the micro-mechanical analysis of laminates, focusing on the failure analysis of a laminate. It explains how the force and moment resultants are related to the mid-surface strains and curvatures of a laminate. The lesson also discusses how to determine the stresses and strains in each lamina of a laminate for mechanical and hydrothermal loading. It further explains how to assess the failure or safety of each lamina in a laminate using appropriate failure theory strength. The lesson also touches on the two modes of failure: intra-laminar and inter-laminar. It provides an illustrative example of how to calculate the first ply and last ply failure of a laminate.

Video Highlights

03:09 - Discussion on the two modes of failure: intra-laminar and inter-laminar
08:27 - Inter-laminar Failure
18:02 - First Ply Failure Load
33:36 - Faliure load of a laminate
44:21 - Applying maximum stress theory
54:44 - Failure of 90 Degree Layer

Key Takeaways

- The failure or safety of a laminate is determined by the failure or safety of each constituent lamina.
- The stresses and strains in each lamina of a laminate can be determined for mechanical and hydrothermal loading.
- The failure of a laminate can occur in two modes: intra-laminar and inter-laminar.
- The first ply and last ply failure of a laminate can be calculated using appropriate failure theory strength.