Structural design sensitivity analysis concerns the relationship between design variables available to the design engineer and structural responses determined by the laws of mechanics. The dependence of response measures such as displacement, stress, strain, natural frequency, buckling load, acoustic response, frequency response, noise-vibration-harshness (NVH), thermo-elastic response, and fatigue life on the material property, sizing, component shape, and configuration design variables is defined through the governing equations of structural mechanics. In this 2-volume set, first- and second- order design sensitivity analyses are presented for static and dynamics responses of both linear and nonlinear elastic structural systems, including elasto-plastic and frictional contact problems.Book I introduces structural design concepts that include the CAD-based design model, design parameterization, performance measures, costs, and constraints. It also discusses design sensitivity analysis of linear structural systems, and discrete and continuum design sensitivity analysis methods.