Lecture
This lecture covers the fundamental concepts of internal stress and strain, constitutive relationships of materials, key material properties, normal and shear strains and stresses, allowable stresses and loads, and design considerations for axial loads and direct shear. The instructor explains the distribution of normal stresses, the line of action of axial forces for uniform stress distribution, and the mechanical properties of materials. Examples are provided to illustrate the application of these concepts in real-world scenarios, such as fitting a plastic liner into a cast iron pipe. The lecture concludes with a discussion on plasticity and the relationship between stress and strain.