Study On Dynamic Properties Of A Tensegrity Tower

Tensegrity systems are of entirely new structural concept. Invented in 1950's, tensegrity systems came from the natural principle of continuous tension and isolated compression. Tensegrity tower is one of the applications of tensegrity concept, which is rationally forced, succinctly fabricated and of various types, till now it is used only in sculpture. Based on construction, construction craft and natural vibration properties of tensegrity tower, dynamic properties of a 30-meter high tensegrity tower and its 6-meter high model have been systematically studied. First, nonlinear finite element method is introduced and calculation model of cable element is studied. The author also get that linear element can simulate cable element.Three methods of analyzing structural mode in ANSYS procedure are compared, Lanczos method is chosen to analyze the frequencies'and modes'changes of the 6-meter model under five different prestressing forces, and the former ten modes of the model under prestress of 465MPa are analyzed concretely.The methods of response chart and time-history analysis that are used to analyze structural seismic response are compared, the structural elements'seismic coefficients of different prestressing forces under frequent and infrequent seismic actions respectively have been analyzed by time-history analysis method, so as the structural elements'seismic coefficients and representative nodes'displacements under the conditions of 465MPa prestress and various directional seismic stimulation of different dimensions.Five different wind speed charts are compared, through developing MATLAB procedure, all the structural nodes'pulse wind speed time-history are simulated. After changing the wind speed time-history into wind load time-history, the structural wind vibration response under different prestressing forces are analyzed with ANSYS procedure.The dynamic tests on the 6-meter model have been carried out. Some representative nodes'frequency response function charts are collected and lower-rank natural vibration frequencies and modes are measured in the tests. The test results and theoretical results are compared.