基于四边形单元有限元原理，计算桁架系统在外力作用下，各节点位移与单元应变。主程序BLOCKMAT.m，从输入文件中读入结点个数，单元个数，结点荷载个数，受约束边界点数，弹性模量，泊松比，厚度，单元定义数组，结点坐标数组，结点力数组，约束信息数组。输入文件inport.txt不同参数代表不同的桁架结构。-Based on quadrilateral finite element principle, calculation of truss system under the action of external force, the displacement of each node and element strain. Main program BLOCKMAT. J m, read from input file node number, cell number, number of nodal load, a constrained boundary points, elastic modulus, poisson s ratio, thickness and unit defined array, node coordinate arrays, nodal force array, array constraints information. Input file inport. TXT different parameters represent different truss structure.