基于板壳有限元理论的薄壁箱梁剪力滞效应

发布时间：2018-04-02 23:00

本文选题：板壳有限元　切入点：薄壁箱梁　出处：《铁道科学与工程学报》2017年04期

【摘要】：为了分析计算薄壁箱梁剪力滞效应,直接从壳体结构特点出发,由8节点曲边四边形膜单元和基于Reinssner中厚板理论的弯曲单元推导考虑剪切闭锁效应的薄壁箱梁空间壳单元刚度矩阵及相应的刚度方程,并在MATLAB上编制相应的计算程序。通过数值算例,将理论计算值与ANSYS有限元结果,模型试验的实测值进行比较,三者吻合良好,验证了理论公式推导的正确性与可靠性。本文采用8节点的等参单元和二次型位移场形函数,不仅适用于计算直线箱梁,也适用于曲线箱梁,因而更具有普遍性。最后,从平衡微分方程的角度解释剪力滞产生的真正原因,不仅仅是由于剪应力沿横向分布不均匀,其本质更在于剪应力沿横向不均匀变化。
[Abstract]:In order to analyze and calculate the shear lag effect of thin-walled box girder, we proceed directly from the characteristics of shell structure.The stiffness matrix and the corresponding stiffness equations of space shell element of thin-walled box girder considering shear latch-up effect are derived from 8-node curved quadrilateral membrane element and bending element based on Reinssner theory. The corresponding calculation program is compiled on MATLAB.Through numerical examples, the theoretical calculation results are compared with the ANSYS finite element results and the measured values of the model tests. The results agree well with each other, and verify the correctness and reliability of the derivation of the theoretical formulas.In this paper, the isoparametric element with 8 nodes and the quadratic displacement field shape function are used, which are not only suitable for calculating the straight box girder, but also applicable to the curved box girder, so it is more universal.Finally, the real cause of shear lag is explained from the point of view of equilibrium differential equation, not only because of the uneven distribution of shear stress along the transverse direction, but also because the shear stress varies unevenly along the transverse direction.
【作者单位】：武汉工程大学资源与土木工程学院;
【基金】：国家自然科学基金资助项目(51378404) 武汉工程大学创新基金资助项目(2016036)
【分类号】：U448.213

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