四节点等参

说明：  可用于计算一般的线性静力学问题。目前它已设计了平面梁单元与平面4个节点的两种单元，但留下接口，可以接入所设计的其他类型的单元。该程序可以处理多种工况、多种类型单元组合结构问题。
(It can be used to calculate general linear statics problems. At present, it has designed two kinds of elements: plane beam element and plane four nodes, but left the interface to access other types of elements. The program can deal with the problems of multiple working conditions and multiple types of unit combined structure.)