Material Models, Residual Stress and Distortion — Lesson 3

This lesson covers the importance of stress analysis in welding processes. It delves into the relationship between stress and strain, the significance of materials models, and the role of empirical and semi-empirical models in stress analysis. The lesson also discusses the impact of temperature, strain rate, and other parameters on equivalent stress values. It further explains the concept of elastoplastic law and the importance of boundary conditions in stress analysis. The lesson concludes with an overview of the factors affecting residual stress and distortion in welding processes.

Video Highlights

01:56 - Importance of empirical models in materials model and how they are based on experimental testing
05:54 - How the body force in stress analysis can be considered due to temperature from thermal analysis
13:42 - How the total strain in stress analysis is the summation of thermal strain, plastic strain, and elastic strain
34:25 - How the stress analysis model can be used to predict the residual stress and distortion in welding processes

Key Takeaways

- Stress analysis is crucial in welding processes to understand the relationship between stress and strain.
- Materials models play a significant role in stress analysis, providing a theoretical basis for comparing experimental data.
- Empirical and semi-empirical models are used in stress analysis, with the former based on experimental testing and the latter combining experimental and physical phenomena.
- The elastoplastic law is used to model deformation processes, considering both elastic and plastic components of strain.
- Boundary conditions are essential in stress analysis, defining displacement constraints or load distributions.
- Residual stress and distortion in welding processes are influenced by factors such as welding procedures, material properties, joint design, and heat treatment.