平面问题等参单元的有限元程序设计，平面弹性力学问题的三结点三角形有限单元法。考虑集中力、静水压力、法向面力和自重体力。-This is finite element programming of isoparametric element on plane problem, it solves the three-node quadrilateral plane elasticity problems using finite element method. It calculates the