Study On Seismic Dynamic Performance Of Container Crane And Analysis Methods Of Anti-seismic Design

The vigorous development of the international shipping industry has led to larger-schale quayside container crane to serve the ever-large container ships. Due to the high center of gravity, the uneven vertical stiffness and the special constraint form with wheel to rail contact, the crane's whole structure will vibrate sharply when earthquake occurs, which may cause derailment, destruction of the legs, beams and boom, and up to collapse of the crane. While, no systematic study or reliable conclustion of the seismic dynamic response of the container crane and its anti-seismic measures have been developed due to the randomicity of earthquakes, complexity of the structure and the contact form.Based on the existing problems and blind spots of recent research, this study focuses on the analysis of the seismic dynamic behavior characteristics of quayside container crane and development of the analysis method by employing theoretical analysis, numerical simulation and experiment. The main research contents and results are as follows:1) The elastoplastic finite element model of container crane is established based on plastic hinge theory. The elastic-plastic response and the failure model of the container crane structures during earthquakes are studied using time history analysis. The stress distribution, dynamic coefficient factor, structural deformation and the wheel pressure which directly related to the seismic design and calculation are obtained. The crane's vulnerable locations and two types of collapse mode are found. With the analysis of the wheel pressure,rocking uplift and torsional uplift of the container crane are predicted during strong ground motions. The effects of material and geometric nonlinearity to the crane's seimic response are statistically evaluated.2) Based on the simulation of the critical condition of uplift using multibody dynamics methods,a friction bearing model used in finite element method to simulate the wheel to rail contact is developed. Then, the machanism, response characteristics as well as the threat to the structure of uplift are numerically simulated. Also, a mathematical model of the uplift process is established, and the related solving methods are provided. Analysis results show that rocking uplift would cause the stress of the legs and beams increased significantly, but the occurrence of torsional uplift trend to reduce structure's maximum stress level and protect the crane from destroying.3) A jointed finite element model of wharf and container crane considering pile-soil interaction and a two-DOF model are developed. The dynamic coupling rules and the crane-wharf coupling vibration response are discussed by analyzing the crane, the wharf and jointed model's dynamic performance respectively. It is found that affecting factors of the crane-wharf coupled vibration include excited frequency, period ratio, mass ratio of the crane and wharf. Compared with the rigid foundation, the coupling vibration is trend to response more strongly, and the dynamic coefficient of the crane increased by 12% to 13%.4) The results of theory and simulation analysis are verified by the experiment data from the shaking table test of a 1:20 analogy model of container crane. The influential factors and the response of uplift are further summarized. The good agreement of the results between simulation and experiment shows the related key technology of modeling and analytical methods in this study are reliable and comprehensive.5) Based on the response spectrum method for multi-degree of freedom system, the key parameters' selection and calculation methods for the constructing technicas of container crane's design spectrum are studied. The response spectrum analysis method for container crane is developed with the combination of the container crane's structure and operating features. The response spectrum analysis of the container crane is conducted and the results agree well with the time-history analysis, which proved that the response spectrum method is feasible and reliable for the seismic design verification of container cranes. Finally, the analysis process and methods for container crane's anti-seismic design based on its dynamic behavior are purposed through the summarization of the whole research work.The achievement of this thesis provides guidance for container crane's seismic design based on the understanding of the container crane's seismic dynamic behavior comprehensively and deeply. The related analysis methods in the paper provide a reference for the revision of the seismic design code of cranes and for the seismic response analysis of other types of cranes.