Nonlinear Dynamic Response And Time-Delay Feedback Control Of Tension Leg-Submerged Floating Tunnel

With the proposal of the national strategy of "Maritime power",Chinese transportation infrastructure is constantly developing to the far sea and deep sea.It is of great importance to study the construction of some reliable,all-weather,and relatively reasonable transportation structures between straits or islands,and solve the major new transportation projects such as the trans-passage of ultra-long deep sea waters in the future.And with the development of society and science and technology,the application of new materials,new equipment,new structure,and new construction technology,the new floating flexible structure will be expected to replace the traditional structure.This study closely follows the hot research field of nonlinear modeling theory and dynamics research of large-span structures at home and abroad and takes tension-leg submerged floating tunnel as the research object.Meanwhile,the nonlinear dynamic response and time-delay feedback of submerged floating tunnel are studied.The specific contents are as follows:1.Based on Euler-Bernoulli beam theory and time-delay feedback control strategy,the force of the tunnel tube on the tension leg was assumed as parametric excitation,and the fluid damping force and additional inertia force were considered.The vibration control equation of submerged floating tunnel tension leg was established by Galerkin method and linear stability analysis.The stability boundary conditions of the control system with time delay are obtained.The influence of different control parameters on structural vibration response is analyzed by numerical calculation.2.Consider when current flows through the tension leg cross flow to the vortex street forces,establish strong arguments-encouraged by the mathematical model of tension leg,and then the multi-scale method is used to solve the approximate solution of the main resonance response of the controlled system,average equation and the amplitude-frequency equation is obtained,and using the stability boundary condition of non-zero solution,the decay rate is the objective function to realize the optimal control,and then the influence of different control parameters on the system response is analyzed by specific examples.3.Taking vertically anchored tension leg submerged floating tunnel as the research object,the tunnel tube and tension leg were assumed as Euler-Bernoulli beam model,and the effects of the fluid damping force and ocean current on vortex-induced lift of submerged floating tunnel were considered.Further established under moving load tunnel tube bodytension leg coupling vibration model and the vehicle-tunnel tube-tension leg coupling vibration model.The effects of moving load,load velocity,flow velocity and pre-tension on the nonlinear dynamic response characteristics of tunnel tube and tension leg are analyzed.And the vibration control of the vehicle-tunnel tube-tension leg coupling model is studied with time-delay feedback technology.