Deriving Governing Equations for Shells - Part 2 — Lesson 3

This lesson covers the in-depth understanding of Shell Governing Equations and their associated boundary conditions. It explains the derivation of these equations, their coefficients, and the integration process. The lesson also discusses the Hamilton principle, kinetic energy, internal and external work done, and the strain energy of an elastic body. It further elaborates on the concept of variational principle and the derivation of ordinary differential equations. The lesson also touches upon the concept of shell theories and the conditions for different types of shells. For instance, it explains the Love Kirchhoff shell theory and the conditions for thin shells. The lesson concludes with a discussion on the state of stress for thin shells and the challenges in solving shell equations.

Video Highlights

01:21 - Hamilton principle and potential energy
04:48 - Fundamental theorem of variational principle
08:06 - Effects of bending force on thin shells
11:54 - Boundary conditions in shell theories
23:54 - Love Kirchhoff shell theory
31:16 - Boundary conditions in Love Kirchhoff shell theory
46:52 - Discussion on the types of state of stress for thin shells

Key Takeaways

- Shell Governing Equations are derived from the Hamilton principle, considering kinetic energy, internal and external work done, and strain energy.
- The variational principle helps in deriving ordinary differential equations.
- Shell theories, such as Love Kirchhoff shell theory, provide conditions for different types of shells.
- The state of stress for thin shells can be categorized into membrane theory of shells and pure bending or flexural state of stress.
- Solving shell equations, especially for irregular shells, is a complex task due to the variable coefficients in the partial differential equations.