This page offers a mathematical framework for kinematic, equilibrium, and constitutive equations crucial for stress analysis of complex geometrical structures. It sets the foundation for theoretical a...This page offers a mathematical framework for kinematic, equilibrium, and constitutive equations crucial for stress analysis of complex geometrical structures. It sets the foundation for theoretical and numerical methods, including finite element analysis, and introduces notation for stress and strain. The chapter also covers stress axis transformation for practical applications, such as analyzing stresses on atomic planes and joints.