局部有限元模型边界条件的直接传递方法

摘要

A new method namely partial mixed finite element method in which the nodal forces or nodal displacements can be transferred from the global model to the refined local finite element model (RLFEM) directly and easily is proposed in this paper.To establish a segment of transitional elements surrounding of the RLFEM,the element type and simulation mode of these elements are consistent with the global finite element model,the relative coordinates of nodes on outer boundary of these transitional elements are correspond with the global finite element model,while the inner boundary of these transitional elements is connected with the RLFEM using surface-based constraint method.The nodal forces or nodal displacements obtained from global analysis are applied directly on the outer boundary of these transitional elements according to corresponding coordinates,so the boundary conditions can be transferred to the RLFEM by the transitional elements.The practicality and effectiveness of this method are verified through the local finite element analysis of steel-concrete joint of Hongshui River Bridge in Guizhou.%提出一种将整体分析得到的节点力或节点位移直接传递到精细化局部有限元模型的方法,即部分混合单元法.沿精细化局部有限元模型周边建立一组过渡单元,该组过渡单元采用与整体模型一致的单元类型和模拟方式,其外侧边界上的节点与整体模型节点的相对坐标对应,内侧边界与精细化局部有限元模型采用基于面约束的方式连接.在外侧边界上根据节点坐标对应施加整体分析获得的节点力或节点位移,过渡单元就可直接将边界条件传递到精细化局部有限元模型.通过贵州红水河特大桥钢-混结合段的精细化有限元分析,验证了本文方法的实用性和有效性.