Understanding Bending and Torsional Deformations — Lesson 4

This lesson covers the complex topic of bending and torsional deformations, focusing on the coupling of these deformations. It explains the concept of swept wings and straight wings, and how they differ in terms of bending and twisting. The lesson also discusses the formulation of the problem in two ways: chord-wise and stream-wise. It further elaborates on the differences between these two formulations and how they affect the equations. The lesson also provides an in-depth explanation of how to derive both chord-wise and stream-wise formulations. For instance, it uses the example of a wing to explain how deformations can cause a change in the angle of attack, affecting the lift coefficient.

Video Highlights

01:24 - Explanation of the bending axis and twist about the elastic axis.
06:34 - Introduction to the two types of formulation: chordwise and streamwise.
15:08 - Explanation of the distributed aerodynamic load and its transfer to the elastic axis.
31:28 - Discussion on the bending and torsional equations for the wing.
55:40 - Explanation of the boundary conditions at the root and tip of the wing.
66:44 - Discussion on the effect of aspect ratio on the lift coefficient.

Key Takeaways

- Bending and torsional deformations are coupled in the case of swept wings.
- The problem can be formulated in two ways: chord-wise and stream-wise, each having its own set of equations.
- The bending and twisting of the wings can cause a change in the angle of attack, which in turn affects the lift coefficient.
- The equations derived can be used to understand and predict the behavior of wings under different conditions.