Study On Method Of Pseudo-dynamic Testing And Theoretical Analysis Of Tube Structure

Tube structure is one of the important styles in tall buildings. Aseismic experiment and theorem analysis of tube structures are researched in the dissertation. The research focuses on three aspects: test and simple calculation of dynamic characteristic of tube structures, study of numerical integration methods of dynamic equation and pseudo-dynamic test, research of aseismic performance and nonlinear analysis of two tube structure models through pseudo-dynamic test. The main contents are listed as follows:(1) The dynamic characteristic of two models, including reinforced concrete tube in tube structure and combined tube structure of concrete filled steel tube, are tested. Information of factors influencing dynamic characteristic, such as vibration frequency, vibration style, damping ratio, model mass, model rigidity and model damping etc., has been obtained in the test.(2) Equivalent rigidity theory is put forward for calculating simply dynamic characteristic of tube structures, in which the structure is simplified as a multi-mass system with flexural and shear deformation to calculate the equivalent flexural and shear rigidity. The analytic results of dynamic characteristic of two tube structure models are in agreement with those of the test and the ANSYS analysis.(3) A new numerical integration format for structural dynamics is advanced on the basis of the Newmark-βmethod. The method is simple and convenient because its calculated displacement is independent of velocity and acceleration. Through discussing precise time-integration method of structural dynamics, this part points out that the accuracy of nonlinear equation depends on the selection of integration method of load item. It also analyses the accuracy and application range of some algorithm, such as Romberg, Cotes and Gauss etc. so as to select a reasonable integration method.(4) Based on the present single-step method and Adams multi-step method, new methods of precise integration are put forward for nonlinear dynamic. The stability and accuracy of the method are superior to the present methods since it changes 2 parts of dynamic equation in traditional method into 3 parts. The superiority of the new methods is obvious in numerical integration. Based on the advanced multi-step method of nonlinear precise integration, new numerical integration methods of...