基于ANSYS二次开发的实体单元模型内力图的实现

当依据规范对结构承载能力极限状态和正常使用极限状态进行设计验算时,需掌握其内力状态.有限单元法对复杂结构进行内力分析有时需要采用空间实体单元,而ANSYS软件不能直接输出实体单元模型的内力图,需另行开发.文中介绍了利用软件后处理中的面操作,通过面积分和矩阵运算并编制APDL宏程序求实体单元模型内力图的方法.给出了4种不同截面形式的连续梁求内力图示例,并对实体单元模型的有限元解与采用三弯矩方程求得的理论解进行了比较.结果表明,文中所述方法可以方便地求得实体单元模型的内力图.

Internal Force Diagram of the Model of Solid Elements Based on the ANSYS Secondary Development

According to the specification, the internal force status needs to be known when the limit states of ultimate bearing capacity and limit states of serviceability of a construction are computed. Sometimes solid elements are required if the internal force of complicated constructions is analyzed with FEA. ANSYS cannot output the internal force diagram of solid element directly; therefore, further development is needed. In this article the surface operation was introduced after using the software, as well as the method to get internal force diagram of model of solid elements by APDL macro language programming combined with surface integration and matrix operation. Four examples of getting the internal force diagram of four different sectional consecutive girders were presented. The FEA solution of model of solid elements and the theoretical solution got from three bending moment equation were compared. The results show that the internal force diagram of model of solid elements can be acquired conveniently with the method proposed in this article.