Principle of Superposition in Statics

This lecture covers the principle of superposition in statics, including cutting a solid to calculate internal forces, identifying non-zero internal forces from constrained displacements, types of structural elements, and the basics of structural behavior of a bar. It also discusses the hypothesis on displacements, internal forces calculation, and the comparison between different structural elements. The instructor demonstrates examples of calculating reactions for initial and deformed configurations, as well as the concept of cutting a solid in equilibrium. The lecture emphasizes the concept of cutting to analyze internal forces, the nature of internal forces, and the association between force and displacement. It concludes with a discussion on the three classes of structural elements and the modeling of bars as structural elements with negligible moments.