基于有限元法的廖坊灌区渡槽结构内力分析

在实际工程的有限元建模求解过程中,所求解的内力截面往往不是直接由网格单元面构成,无法直接应用有限元内力法求解任意截面的内力值。首先对整体结构构件进行有限元计算,得到网格单元上的结点位移值及对应的应力值等信息;然后将截面所在结构组件的网格单元从三维有限元模型中进行脱离,直接利用"脱离体"网格单元结点的应力值列出截面平衡方程。根据结构力学的方法,可以很方便地对"脱离体"上的"任意"截面的内力进行求解;最后通过一个渡槽的工程应用实例验证了文中提出方法的正确性和可行性。有限元内力法可以很方便地求解结构中指定截面上的内力值,为混凝土结构的配筋设计等提供依据,供工程设计人员参考。

Finite element method-based analysis on structural internal force of Liaofang Aqueduct

During solving finite element modeling for actual engineering project，the cross-section for the internal force to be solved is often not directly constituted with the grid element planes，thus the internal force value of an arbitrary cross-section cannot be directly solved with the finite element internal force method. In accordance with the method proposed herein，the finite element calculation is made on the integral structural member to get the information of the displacement value of the node on grid element，its corresponding stress value，etc. at first，and then the grid element of the structural member that the cross-section is located on is separated out from the 3 － D finite element model; from which the stress value of the node of the separated grid element is directly used to write the balance equation for the cross-section. Subsequently，the internal force of arbitrary cross-section on the separated element can be conveniently solved in accordance with the method of structural mechanics. The correctness and feasibility of the method proposed herein are verified through an actual engineering application case of an aqueduct project at last. The finite element internal force method can conveniently solve the internal force value of a designated element in structure， and then provide a referential basis for the reinforcement design of concrete structure for the engineering designer concerned.