考虑流固耦合的渡槽结构三维碰撞反应研究

Three-dimensional pounding response of aqueduct structures in consideration of fluid-solid coupling

渡槽结构在强烈地震作用下邻梁间发生的碰撞现象易对其输水安全造成重大影响。采用薄壁梁段单元和三维接触-摩擦单元借助FORTRAN程序建立了考虑流固耦合的渡槽结构整体三维碰撞分析模型,并通过工程实例进行了多工况下的地震碰撞反应分析。结果表明,随着槽内水深的增大,渡槽结构的地震反应普遍增大,邻梁碰撞次数、碰撞力和相对转角也随之增大;槽内水体固结和考虑流固耦合的碰撞反应峰值相差不大,但时程曲线差异较大,某些部位水体固结的解会小于流固耦合解,使固结简化的处理偏于不安全。研究结果可供大型渡槽结构抗震设计参考。

Pounding response between two adjacent aqueduct girders is easy to pose a major threat to its water conveyance safety under strong earthquakes. By the aid of FORTRAN programs,a three-dimensional pounding analysis model of the aqueduct structures was established using thin beam element and 3D contact-friction element and was applied to an engineering example to study the seismic pounding response under multi-conditions. Results show that the seismic response of aqueduct structure is generally increased with the increase of water depth in the groove, and the pounding force as well as frequency and relative rotation of adjacent girders are also increased. Whether making the water in the tank consolidated or considering the fluid-structure interaction bring about little difference for peak pounding responses, but the time history curves are quite different. Besides,the analysis results of some parts of struclure with water consolidated might be less than that with fluid-structure interactions which may make the consolidation-simplified result to be unsafe. Research results of this paper give a reference to seismic design of aqueduct structures.