斜T型梁桥的有限元分析

Finite Element Analysis of Skew T-beam Bridge

目前,对于梁板组合的斜T型梁桥的计算方法,从计算理论上可分为板理论和梁理论两大类,从计算方法上可归纳为梁格法和各向异性板法。而这两种方法的计算结果都未能把梁和板所受的力区分开,这就给梁和板的配筋计算带来一定困难。为此,文章从分析模型和计算方法入手,考虑了梁和板的组合作用,推导出了板作为平面壳体单元的单刚阵,主梁和横梁以板中面作为弯曲中性轴的梁单元单刚阵,较好地解决了这个问题。并依此思路研制了有限元分析程序,对一些实验模型桥进行了分析比较,结果十分接近。

Up fill now theories for beam slab structure in oblique T-beam bridge can be classified as plate theory and beam theroy. Based on these theories, there are two essentialy computation methods, i.e.anisotropic slab method and beam/mesh method.But the results of the methods mentioned above can not seperate the force acting on beam from the force on slab, which makes it difficult to caculate the reinforcement.For this reason, considering the interaction of beams and slab, by use of analyzing models and caeulation methods, the paper infered the element stiffness matrix of plate as a plain shell and the element stiffness matrix of beam （girder frame） dement with the medial plain of plate as its neutral layer, and resolved the problems mentioned above adequately. Using these two kinds elements, a finite dement analysis programe has been developed. Comparisons have been made with some experimental values of model bridge, with adequate results.