This lecture covers the behavior of axially loaded members, including length changes, statically indeterminate structures, stress concentration, and nonlinear behavior. It discusses the elongation of members under tension and compression, the use of cables for large tensile forces, and provides examples of frame constructions and problem-solving approaches. The lecture also explores changes in length under nonuniform conditions, members with continuously varying loads or dimensions, axial force and displacement diagrams, and the analysis of member elongations due to different loads.