Prescribed Dynamic Response Analysis Of Isolated High-Position Connected Structure

The visual effect of the connected structure is novelty and unique,and the building shape changes abundance.However,its complex mechanical characteristics have brought many difficulties to structural design work.Under the action of the earthquake,connected structures are susceptible to destruction caused by falling connector from high altitude and severe damage to vertical components of the main structure caused by joints.In order to avoid the damages,many scholars have studied the simplified model of connected structure,calculation methods,dynamic characteristics,mechanical behavior,joint structure,and the correlation between various types of influencing factors and dynamic response.Studies show that the shock absorbing characteristics of structure can be improved effectively by installing isolation bearings,viscous dampers,and buckling restrained brace in the connected structure.At present,the isolation bearings are mostly used in connected structures to form flexible connection between tower and connection to reduce the mutual influence of the towers on both sides of connection.Few studies talk about installing isolation layer on both sides of the tower.Therefore,it is necessary to study the influence of installing isolation layer on the dynamic response of connected structure.In this paper,the prescribed dynamics response of a symmetry twin-tower high-position connected structure with isolation layer is researched and proposed to reduce the dynamic response by installing isolation layer.The main contents of the paper are following four aspects:(1)Research on prescribed dynamic analysis methods.The establishment and solution of the movement equation of general multi-degree-of-freedom system are discussed,and three kinds of time-domain methods for simulating traveling wave effects are further elaborated.Based on multi-point system’s simplified model,the movement equation of base-isolated systems and story-isolated systems are introduced.Multi-point simplified model of twin-tower high-position connected structure is established,the change trend of dynamic characteristics of the system is analyzed,and the displacement expression of the system under sinusoidal loading is deduced.(2)Effect of isolation layer position on dynamic response of connected structures.By means of nonlinear dynamic analysis,the change rules of the storey shearing force,inter-story drift,connection internal force under the horizontal two-way incentive when the isolation layer is located at the bottom,middle and lower part of the symmetrical twin tower high-level connected structure are studied.(3)Effect of isolation layer stiffness on dynamic response of connected structures.The isolation layer is set in the lower part of the conjoined layer to form a high-level connected story-isolated systems,the response of the structure under dynamic loading is compared by controlling the stiffness ratio of the seismic isolation layer and the substructure.(4)Effect of traveling wave effect on dynamic response of long span high-position connected structures.Based on the forced displacement method,the dynamic analysis is carried out for a large-span connected structure with isolation layer under uniform excitation and non-uniform excitation,and compared with the results of dynamic analysis of non-isolated structures.