虚拟层合单元与杆单元在桥梁预应力混凝土结构分析中的合成方法

对预应力混凝土的计算方法和研究现状做出了评价,提出针对预应力混凝土结构分析的单元形式。通过自由度变换,把空间杆单元的节点自由度用空间虚拟层合单元的节点自由度来表示,即杆单元的节点无需固定在体单元节点上,共同模拟了预应力混凝土结构。在单元内采用选择性积分的方法计算单元刚度矩阵,用较少的单元模拟出了复杂的断面形式;并采用单独的空间杆单元模拟预应力束,能直接求解预应力对结构产生的变形和内力。经实例验证分析,使用该单元进行预应力混凝土结构分析,在网格划分比较稀疏的情况下,仍然获得较为精确的结果,较传统的预应力计算方法更为简单、更为准确。

Method of Combining Virtual Laminated Elements and Bar Elements for Analysis of Prestressed Concrete Bridge Structures

Research actuality and numerical calculation of prestressed concrete structure were evaluated,and a kind of element aiming at prestressed concrete structure analysis was proposed.By the method of transforming the node DOF of the space bar element to the node DOF of the space virtual laminated element,that is,the node of bar element need not fixed on the node of space solid element,the prestressed concrete structure were simulated together.Selective integral method were adopted to calculate element matrix,which can simulate complex sections with less elements.Moreover,independent space bar element was adopted to simulate prestressed strand,which can directly solve the displacement and internal forces of the structure by prestress.It is shown that through prestressed concrete structure analysis by using this kind of element,a comparably accurate result can be obtained even the finite element gridding is sparse.It is a more simple and accurate method than the traditional method of prestress calculating.