Constitutive Equations for Engineering Materials, Volume 1: Elasticity and Modeling, Revised Edition focuses on theories on elasticity and plasticity of engineering materials. The book first discusses vectors and tensors. Coordinate systems, vector algebra, scalar products, vector products, transformation of coordinates, indicial notation and summation convention, and triple products are then discussed. The text also ponders on analysis of stress and strain and presents numerical analysis. The book then discusses elastic stress-strain relations. Basic assumptions; need for elastic models; isotropic linear stress-strain relations; principle of virtual work; strain energy and complementary energy density in elastic solids; and incremental relations grounded on secant moduli are described. The text also explains linear elasticity and failure criteria for concrete and non-linear elasticity and hypoelastic models for concrete. The selection further tackles soil elasticity and failure criteria. Mechanical behavior of soils; failure criteria of soils; and incremental stress-strain models based on modification of the isotropic linear elastic formulation are considered. The text is a good source of data for readers interested in studying the elasticity and plasticity of engineering materials.