Shaking table experimental investigations on dynamic characteristics of CFRP cable dome

Abstract

Carbon fiber reinforced polymer (CFRP) bars have the feature of lower density, higher strength and better anti-fatigue performance compared with steel bars. Therefore, CFRP is a kind of ideal material for a long-span spatial structure. To explore the dynamic performance of spatial structures and take full advantages of CFRP bars in long span cable dome structures, a CFRP cable dome scale model with a diameter of 5.4 m was designed for a shaking table test. In this model, struts and cables were made of CFRP material except that the internal ring beams were fabricated with steel. In the test, new types of joint forms and anchoring configurations for CFRP cable dome structures were proposed because the existing forms for steel domes cannot be applied to CFRP dome structures. In addition, three kinds of seismic waves including Elcentro wave, Kobe wave and Pasadena wave were selected to generate 12 load cases and the maximum acceleration was 900 Gal. The acceleration and strain response of the model under different types of seismic waves was researched. It is demonstrated that middle-ring upper joints have the largest acceleration response because the control vibration modes of the CFRP cable dome structure are anti-symmetric mode. In addition, a CFRP dome numerical model was established to carry out modal analysis by program ANSYS. By comparing the results of finite element modal analysis with the measured frequencies, the natural vibration modes of the structure are analyzed. Based on the results of seismic wave spectrum analysis and structural modal analysis, the Pasadena wave, which has a wide low frequency region for high Fourier amplitude, can excite the greatest acceleration response.