Evaluation of Hygrothermal Properties — Lesson 1

This lesson covers the determination of stiffness and strength parameters using micromechanical models. It delves into the mechanics of material approach and its limitations. The lesson further discusses the determination of the coefficient of thermal expansion and coefficient of moisture expansion, which are responsible for the hygrothermal response of a lamina. The lesson also explains how to determine these coefficients using micromechanical models. For instance, it explains how the coefficient of thermal expansion of a fiber-reinforced polymer matrix lamina in the longitudinal direction is less compared to that in the transverse direction due to the restraining effect of the fiber on expansion in the longitudinal direction.

Video Highlights

01:11 - Explanation of the hygrothermal response of a lamina
02:32 - Discussion on the restraining effect of the fiber on expansion
12:33 - Discussion on Coefficient of thermal expansion
15:21 - Determination of the coefficient of moisture expansion
28:29 - Discussion on the determination of coefficient of moisture expansion
38:53 - Conversion of Mass Fraction to Volume Fraction

Key Takeaways

- The determination of stiffness and strength parameters is crucial in understanding the behavior of materials.
- The mechanics of material approach has its limitations and may not always provide accurate results.
- The coefficient of thermal expansion and coefficient of moisture expansion play a significant role in the hygrothermal response of a lamina.
- The coefficient of thermal expansion of a fiber-reinforced polymer matrix lamina is less in the longitudinal direction due to the restraining effect of the fiber.
- The determination of the coefficient of moisture expansion is similar to the determination of the coefficient of thermal expansion.