在matlab中，采用矩形单元计算纯弯梁的变形，研究对象是一承受纯弯曲的梁(The rectangular element is used to calculate the deformation of pure curved beam. The object of study is a beam subjected to pure bending. The length width height is 9*6*1cm. Due to symmetry and antisymmetry, 1/4 beam is only needed to be calculated.)