Seismic Response Analysis Method And Application Of Ship Loader

With vigorous development of the international shipping industry,the importance of the port is increasing day by day.As the essential equipment of a port for the bulk loading process,Ship loader has the characteristics of high working frequency and large workload.Due to the high center of gravity,complex structure and the uneven distribution of the lateral stiffness,the structure of modern mobile ship loader will be a substantial shake,resulting in plastic deformation in boom,column and other structures or even broken when a natural disaster occurs,especially a strong earthquake is encountered.Sometimes the earthquake can lead to the collapse of the whole machine,causing major disaster accidents.For the seismic research of port loading and unloading equipment,especially large-scale ship loader,there are few studies on the dynamics,which are mainly related to the static research.The study of dynamics behavior for ship loaders are rare in literature,Therefore,the researches of dynamic mechanical behavior for ship loaders have a certain theoretical significance and engineering value.In this dissertation,the 1500t/h ship loader is taken as the research object,the seismic response characteristics of ship loader under earthquake excitation are studied by different seismic analysis methods.The main contents are as follows:(1)The finite element model of ship loader is established.The seismic load combination is developed according to its workplace and the stress and displacement of the ship loader are calculated by static method under 7 and 8 degree seismic loads respectively.The leg pressure is extracted to analyze its stability under the condition of different seismic loading.The results are compared and analyzed,and the weak part of the structure is found,which can provide reference for the response spectrum analysis and time history analysis.(2)According to the different angle of the ship loader' boom,the modal analysis is carried out under three conditions of the ship loader to provide the required modal frequency for the response spectrum analysis.According to the results of modal analysis,the seismic response spectrum analysis is carried out,and the response spectrum response of the ship loader is obtained.Compared with the static theory,the response spectrum theory is a more accurate theory than the static method because of the factors such as site condition and structural damping.(3)On the basis of time history analysis theory and damping theory,the selected El-Centro seismic wave,Taft seismic wave and a simulated seismic wave are treated under the condition of 7 degree earthquake level,and the treated seismic wave is loaded directly into the loading machine in the form of seismic time-Linear time history analysis.(4)On the basis of introducing the principle of the vibration isolation equipment of the port equipment and the type of the vibration isolation device,the seismic isolation scheme suitable for the mobile ship loader is selected and the finite element model of ship loader with isolation device is established and its response spectrum analysis and time history analysis are carried out.The analysis shows that the seismic response of the key position is reduced after the vibration isolation device is added,which proves the effectiveness of the vibration isolation device.