The recent success and popularity of the finite-element method, crucial to solving mathematical problems in many branches of engineering today, is based on the variational methods discussed in this textbook. The author, Toshio Mura, is a distinguished engineer and applied mathematician who brings to the work a highly pragmatic approach designed to facilitate teaching the subject, which is essential for all materials science and mechanical and civil engineering students. In addition to all basic topics, the authors cover state-of-the-art research findings, such as those involving composite materials.