This lesson covers the micro mechanics of lamina, focusing on the determination of longitudinal tensile strength, transverse tensile strength, and longitudinal compressive strength of a lamina. It explains how the volume fraction influences the longitudinal tensile strength and how the strength of a composite or lamina is affected by factors such as fiber orientation, non-uniform strength of fibers, discontinuous fibers, and the interface between the fiber and the matrix. The lesson also discusses the impact of residual stresses on the strength of a laminated composite. It provides a detailed explanation of the failure modes under compression and the determination of transverse compressive strength.
01:53 - Discussion on the critical volume fraction and how it affects stress strain curve
04:26 - Discussion on the factors influencing the strength of a composite or lamina
10:49 - Explanation of the determination of transverse tensile strength
33:47 - Discussion on the determination of longitudinal compressive strength
36:32 - Explanation of the determination of transverse compressive strength
41:42 - Discussion on the determination of in-plane shear strength
- The longitudinal tensile strength of a lamina is decided by the fiber failure only.
- The volume fraction plays a crucial role in deciding the longitudinal tensile strength of a lamina.
- The strength of a composite or lamina is influenced by factors such as fiber orientation, non-uniform strength of fibers, discontinuous fibers, and the interface between the fiber and the matrix.
- The transverse tensile strength of a lamina is influenced by factors like bond strength of the interface and presence of voids.
- The longitudinal compressive strength of a composite is complicated due to different failure modes under compression.