WALTER D. PILKEY, PHD, was the Frederick Morse Professor in the Department of Mechanical, Aerospace, and Nuclear Engineering at the University of Virginia and a leading authority in the areas of stress and strain in mechanical and civil engineering. He is the author of Formulas for Stress, Strain, and Structural Matrices, Second Edition, and Analysis and Design of Elastic Beams, all from Wiley. DEBORAH F. PILKEY, PHD, is an Engineer and Scientist in the Loads & Environments Department at Orbital ATK in Utah. She has been involved with structures technology, loads, dynamics, and production stress analysis of the Space Shuttle”s main engines and their solid rocket motors. ZHUMING BI, PHD, is a professor of Mechanical Engineering. He is affiliated with the School of Electromechanical Engineering and Automation, Shanghai University and the Department of Civil and Mechanical Engineering at Purdue University. He has over 25 years of experience in Machine Design, Modelling & Simulation, and CAD/CAM.