Seismic responses and dynamic characteristics of boom tower crane basing on measured strong earthquake excitation

Abstract

With the wide use and longer life cycle of tower crane, the risk of coming across earthquake during service period increases. Hence, the seismic responses and dynamic characteristics of tower crane are becoming more important. In this paper, seismic responses and dynamic characteristics of boom tower crane were analyzed basing on measured strong earthquake excitation. The finite-element models of boom tower crane were established on Ansys platform. Key locations of max stress with different working conditions were confirmed. The stress and displacement of key nodes were compared and analyzed in time-history response with measured earthquake excitation. It was found that the sensitivities of different modes to the change of jib angle were distinct. Meanwhile the change of jib had a greater effect on dynamic characteristics of tower crane than the change of required lift capacity. When the jib was in small angle, numerical results showed that the lifting heavy object could be regarded as inertial damper, which absorbed earthquake energy and reduced displacement of tower crane partly. The results are of practical significance for seismic design and the layout of stability monitoring stations in tower crane.