为得到悬浮隧道锚索模态耦合内共振特性,建立了悬浮隧道锚索面内、外耦合非线性振动偏微分方程。根据锚索的线性振动模态,通过Galerkin方法,将该偏微分方程转化为常微分方程,得到锚索面内一阶模态与面外一阶模态的耦合振动方程。采用数值分析方法,研究悬浮隧道锚索的1∶1模态耦合内共振特性。结果表明:锚索在面内简谐荷载作用下,在一定的激励频率和激励幅值的作用下容易产生模态耦合内共振;在模态耦合内共振频率区间内,随着频率比的增大,锚索产生模态耦合内共振所需激励幅值逐渐增大;且在此区间内,随着激励幅值的逐渐增大,锚索的面内跨中振幅逐渐增大,而锚索的面外跨中振幅由零逐渐增大,达到峰值后逐渐减小,直至恢复纯平面振动。
To study the modal coupling internal resonance characteristics of a submerged floating tunnel anchor cables,the nonlinear vibration partial differential equation of anchor cables was set up,in which in-plane and out-ofplane coupling of the cable were taken into account. According to linear vibration modal of the cable,the partial differential equation was converted into ordinary differential equation by Galerkin method and the coupled vibration equation of cable for the first modal in-plane and the first modal out-of-plane were obtained. The one-to-one modal coupling internal resonance characteristics of the submerged floating tunnel anchor cable was studied by numerical analysis method. The results showed that the cable subjected to plane harmonic load was prone to producing modal coupling internal resonance for certain excitation frequency and amplitude; in the range of modal coupling internal resonance frequency,the required excitation amplitude for modal coupling internal resonance of the cable increased as frequency ratio increased; also in the range,the in-plane mid-span amplitude of the cable increased as excitation amplitude increased; while the out-of-plane mid-span amplitude increased gradually and decreased gradually after the peak value until the restoration of pure plane vibration.