雨载作用下浮顶结构有限元分析的载荷修正法

A load-modifying method for finite element analysis of floating roofs under rainwater loading

浮顶结构的受力与变形之间存在着非线性的耦合关系,这给计算分析带来了很大的麻烦。为了解决这一问题,本文提出了单盘式浮顶结构在雨水载荷作用下有限元分析的载荷修正计算方法。通过对浮顶结构力学模型的分析,建立了浮顶结构载荷与单盘挠度之间的关系式,并基于这一关系式给出了浮顶结构有限元分析的载荷修正法和相应计算方案。载荷修正法的基本思想是,首先利用有限元方法对浮顶结构进行几何大变形非线性分析,然后通过迭代修正来调整载荷大小,使得计算得到的载荷与挠度满足给定关系式,最终获得浮顶结构的变形与受力情况。最后,将计算结果与试验结果进行了比较,验证了本文提出的计算方法的有效性和可靠性,为浮顶结构的进一步有限元分析打下基础。

The load and deformation of floating roofs are usually coupled nonlinearly, which results in some difficulties for the analysis. This paper proposes a load-modifying method for the finite element analysis of the single-deck floating roof under rainwater loading. According to the loading analysis of the floating roof, the relationship between the load and deflection is established, and the load-modifying method and corresponding computational solution for the finite element analysis of the floating roof are developed based on this load-deformation relationship. In the procedure with the load-modifying method, an initial condition is firstly assumed to begin an iterative computation, and then the load magnitudes in the current iteration are modified with the analysis results in the previous iteration. The geometrically nonlinear analysis of the floating roofs is carried out based on the finite element method. Then the loading magnitude is modified with a series of iterative computations until the computational results meet the given load-deformation relationship, through which the final results are obtained. Finally, the computational results are compared with the experimental ones, and the validity and reliability of the proposed method are demonstrated, which provides an effective solution for further finite element analysis of floating roofs.