物体在外力的作用下会发生形变。当外力消除后、物体的形变能立即完全消失,这种形变叫做弹性形变。弹性形变可分为拉伸(或压缩)、切变、扭转和弯曲等四种基本类型。虽然在实际中看到的形变往往是很复杂的,但它们总可以看作是由上述这些基本形变中的某几个组成的。物体在外力作用下所发生的弹性形变的 Objects under the action of external forces will be deformed. When the external force is removed, the deformation of the object can disappear immediately and the deformation is called elastic deformation. Elastic deformation can be divided into stretching (or compression), shear, torsion and bending of the four basic types. Although the deformations seen in practice are often complex, they can always be considered as consisting of some of these basic deformations. Objects under the action of external force occurred by the elastic deformation