悬浮隧道锚索多阶涡激非线性振动

为研究悬浮隧道锚索高阶涡激非线性振动,建立了悬浮隧道锚索在涡街和参数激励作用下振动的数学方程,并用多阶伽辽金法对其进行了化简,运用四阶龙格-库塔法进行了数值求解.通过一系列数值算例对流作用下悬浮隧道锚索的多阶涡激振动响应进行了分析.结果表明:涡街单独作用时,第一阶谐振响应最大,二、三阶谐振响应逐渐减小;产生涡激谐振的模态响应最大,其他阶的模态响应很小.参数激励单独作用时,一阶参数振动的响应最大,二、三阶参数振动的响应逐渐减小;产生参数振动的模态响应最大,其他阶的模态响应很小;锚索的高阶涡激非线性振动不可忽视.锚索产生参数振动时,是否产生涡激谐振对模态响应的影响不大,涡激振动仅为参数振动提供恒定扰动的作用.

Multi-order vortex-induced nonlinear vibration of submerged floating tunnel tether

A mathematical equation of submerged floating tunnel tether vibration under the effects of vortex and parametric excitation was presented to investigate the importance of its high-order vortex-induced lock-on vibration.Multi-step Galerkin method was used to simplify this equation and then fourth-order Runge-Kuta integration method was used for numerical analysis.Finally,multi-order vortex-induced vibration response of submerged floating tunnel tether subjected to current was analyzed in a few numerical examples.The results show that,when the vortex acts separately,modal response of tether decreases as the order of lock-on increases,and the modal response of the order where lock-on occurs is the biggest,whereas that of the other two orders are small;when parametric excitation acts separately,the similar thing happens,and high-order vortex-induced lock-on of tether should not be ignored;whether the lock-on takes place or not doesn't have a significant influence on the parametric vibration of tether,and vortex-induced vibration of tether merely supplies a constant disturbance to parametric vibration.