多厢矩形渡槽槽身弹性稳定分析的梁壳复合有限条法

摘要

A mathematical model using the beam-shell compound finite strip method is developed to study the elastic stability analysis of multi-trough rectangle aqueducts. The model takes some impacts of transverse stiffeners and crossbars into account. The principle of minimum potential energy is used to deduce the eigenvalue equation for elastic stability problems. To verify the accuracy and efficiency of the beam-shell compound finite strip method, a comparison of the theoretical results of the stability analysis for a rectangle plate with transverse stiffeners is made and the numerical solution of the stability analysis for an actual aqueduct is calculated through the model and other methods. The stability analysis results of an actual aqueduct show that the buckling coefficient decreases as the water level increases while buckling mode remains constant; and the prestressed load has a great impact on not only the buckling coefficients but also the buckling modes.%应用梁壳复合有限条法建立了多厢矩形渡槽槽身弹性稳定分析的计算模型,模型中计入了槽身内横向加劲肋及横向连系拉杆的影响,基于最小势能原理推导出弹性稳定问题的特征值方程,并编写了相应的计算程序.通过与矩形加肋板稳定性问题的理论解及工程实例数值解的比较表明,应用梁壳复合有限条法时单元划分数目少、数据处理简单,具有良好的求解精度和效率.工程实例计算结果表明,随着水位的增加,槽身弹性稳定系数降低,屈曲模态未改变；预应力荷载不仅对稳定系数影响显著,而且改变了槽身的屈曲模态.