[关键词]
[摘要]
提出了一个圆管渡槽内流体晃动分析的等效简化模型。将圆管渡槽内的水体假定为无黏性、 无旋、 可压缩及 小幅晃动的流体, 横向晃动的流体可等效为一个固定质量 M 0 与一个质量2弹簧系统( M 1 , K 1 ) , 根据等效原则, 即实 际的流体系统( 采用有限元模拟) 与等效模型具有相同的一阶自然晃动( 振动) 频率, 以及对槽身具有相同的作用效 应。采用最小二乘算法, 通过数值拟合可得到等效模型中固定质量 M 0 、 弹簧振子( M 1 , K 1 ) 及其位置的近似计算公 式。应用流体等效简化模型和有限元模型分别对某一管线桥流体2结构耦合系统的自振频率与地震反应进行了计 算分析, 数值算例表明两个模型的计算结果非常吻合, 验证了流体等效模型的有效性与适用性, 为圆管渡槽支撑结 构地震反应分析提供一个简化的流体计算模型, 可为渡槽抗震研究者与结构工程师提供参考。
[Key word]
[Abstract]
In this paper, a simplified equivalent model was proposed to analyze the sloshing fluid in the pipeline bridge. The water motion in a pipeline bridge is assumed to be inviscid, irrotational, compressible, and linear (small displacement) . T he transverse sloshing fluid in a pipeline bridge can be simplified as a fixed rigid mass M 0 and a mass2spring system ( M 1 , K 1 ) . According to the equivalence rule, the actual fluid ( computed by the finite element model) and its equivalent model have the same the first sloshing frequency and the same effects on the pipe. The approximate analytical formulae of the fixed mass M 0 , mass2spring oscillator (M 1 , K 1 ) , and its locations in the pipe were acquired by the least2squares and curve fitting algorithms. T he simplified equivalent fluid model and fininte element model were used to calculate the first natural frequency and seismic response of a pipeline bridege (fluid 2structure coupling system). The numerical results calculated by the two fluid models agreed well, which confirmed the validity and accuracy of the equivalent model. Therefore, the simplified model of sloshing fluid can analyze the seismic response of the support structure of pipeline bridge, which can provide reference of seismic resistance for the researchers and structural engineers.
[中图分类号]
[基金项目]
国家自然科学基金( 51279133)