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 energy principles (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 2, Nonlinear Systems and Applications, covers design sensitivity analysis of nonlinear structural systems using continuum design sensitivity analysis methods. It also discusses practical design tools and applications; sizing and shape design parameterization, design velocity field computation, numerical implementation of the sensitivity for general-purpose code development, and various other practical design applications. About the Authors: K.K. Choi is a Carver Professor of Mechanical Engineering at The University of Iowa. He teaches in the Mechanical and Industrial Engineering Department, and is a researcher in the Center for Computer Aided Design. His research area is in mechanical system analysis, design sensitivity analysis, and reliability based design optimization. He has authored numerous publications and has twice won the ASME Best Paper Award. He is an associate editor for four national and international journals, a fellow of ASME, and associate fellow of AIAA. N.H. Kim is an Assistant Professor in the Department of Mechanical and Aerospace Engineering at The University of Florida. His research area is in structural design optimization, design sensitivity analysis, nonlinear structural mechanics, structural-acoustics, and mesh-free method. Both authors are members of several professional societies including the American Society of Mechanical Engineers, American Institute of Aeronautics and Astronautics, the International Society for Structural and Multidisciplinary Optimization, and Society of Automotive Engineering.