Analysis On Wave-passage Effect Of The Steel-concrete Composite Ribbed Shell Structure

The steel-concrete composite ribbed shell structure has the characteristics of largespan, big stiffness, high bearing capacity, low cost, etc. It is a good engineeringapplication prospect of new forms of shell structure. With the rapid development ofeconomy, long-span space structures have been developed fast,such as largegymnasiums, exhibition halls，opera houses, train stations, airports, aircraft hangars, etc.More requirements of such large-span public buildings are proposed. Their seismicperformance, wind resistance, impact load performance are more and more be takenseriously.The long-span space structure is very sensitive to seismic response. Large vibrationtends to occur in the earthquake, the structure appear large internal force anddeformation. And with the increase of span, considering spatial effects of seismicoscillation, using multipoint input is very necessary. Start from the traveling wave effect,the seismic performance of steel-concrete composite ribbed shell structure were studied.Firstly, on the basis of the results of existing research, a new composite shellstructure was proposed, It was spherical steel-concrete composite ribbed shell structurewith a ring beam. Secondly, We have studied the vibration characteristics of this kind ofstructure. Found that the space integrity of the structure is better, their space stiffness isuniform, their free vibration frequencies may be very close. Then, Several multi-pointseismic input method were analyzed and compared, choose the large-mass method as away of multi-point seismic input. Finally, Use ANSYS software for spherical steel-concrete composite ribbed shell structure overall modeling and traveling wave effect. Comparing uniform excitation and the large-mass method of multi-support excitation,the seismic responses of the structure under the large-mass method of multi-supportexcitation are larger than those under uniform excitations. As conducting time historyanalysis, multi-support simple-direction excitation and multi-support three-directionexcitation were used respectively. Take the apparent velocity as100m/s,200m/s,400m/s,800m/s, infinity (Not considering the wave-passage effect). The results show thatwith the increase of the apparent velocity, traveling wave effect is not obvious, and inmost cases, traveling wave excitation is unsafe. The response of multi-supportthree-direction excitation are larger compared with multi-support simple-directionexcitation. However, the effect of the wave-passage effect under multi-supportthree-direction excitation is smaller.