平面8节点单元类，可以输出单元的刚度、质量、阻尼矩阵，并可通过形函数插值得到内部各点得位移、应力等。对各位以前编写的程序的一个补充和完善吧。-plane eight-unit category, the output unit stiffness, mass, damping matrix, through the shape function can be interpolation points in the internal displacement and stress. Right before you and the procedure for the preparation of a supplement and perfect it.