Prediction of Delamination — Lesson 2

This lesson covers the concept of interlaminar stresses in laminates, their formation, and the reasons for their development. It explains the mechanics of interlaminar stresses at the free edges of a laminate, and how they are induced. The lesson also discusses the three interlaminar stresses: tau xz, tau yz, and sigma z. It further elaborates on the reasons for the development of these stresses, such as property mismatch in adjacent layers. The lesson then moves on to explain how to determine these stresses, either analytically or numerically. It also discusses the concept of delamination and how it can be assessed using stress-based and fracture mechanics-based approaches. For instance, the lesson explains how the strain energy release rate can be used to determine whether a delamination will grow or not.

Video Highlights

02:04 - Reasons for the development of interlaminar stresses
07:48 - Determination of interlaminar stresses
23:33 - Delamination and its assessment
26:53 - Stress-based and Fracture mechanics-based approaches
44:53 - Three moodes of Fracture

Key Takeaways

- Interlaminar stresses are induced at the free edges of a laminate due to property mismatch in adjacent layers.
- These stresses can be determined either analytically or numerically.
- Delamination, a common issue in laminates, can be assessed using stress-based and fracture mechanics-based approaches.
- The strain energy release rate is a key parameter in determining whether a delamination will grow or not.
- Understanding these concepts is crucial in the design and analysis of laminated composites.