Which of the following expressions most ac curately and simply represents the comple mentary strain energy density Uc of a linear elastic material?

1. Deformation process of polycrystalline materials Deformation process of industrial material consists of three stages Elastic. which is reversible

§3-1 Work（功） §3-2 Kinetic Energy（动能）and The Law of Kinetic Energy（动能定理） §3-3 Conservative Force（保守力） & Potential Energy of Weight Elastic Potential Energy （弹性势能） Universal Gravitational Potential Energy §3-4 Conservation of Mechanical Energy（机械能） §3-5 The Conservation of Energy