Seismic Study Of The Container Crane Structure Considering The Second-Order Effect Of Gravity

In recent years,with the rapid development of the world economy and the promotion of China's “One Belt,One Road” policy,the international port and shipping industry are facing new development opportunities.In order to meet the needs of port development,the trend of intellectualization and large-scale development of the quayside container crane(container crane)is becoming more and more remarkable.The large-scale structure increases the height of the portal frame and raises the center of gravity,which makes the container crane structure more vulnerable to strong earthquakes.Therefore,the seismic design of the container crane structure has higher requirements.In addition,due to the increase in the height of the container crane structure and the high flexibility of the structure itself,the second-order effect of gravity of the structure has increasingly become a factor that must be considered in seismic analysis.This paper focuses on the analysis and research on the influence of the second-order effect of gravity on the seismic performance of the large-scale container crane structure.The main work done are as follows:(1)The finite element model of the container crane structure is established,and analyzes the seismic dangerous working conditions.Combine with the characteristics of the container crane structure and the seismic load calculation criteria,and perform static analysis of the 7 and 8 degree seismic fortification seismic loads on the container crane.The most dangerous condition and structure vulnerable position are found out,which provides comparative data for dynamic analysis.(2)The influence of the second-order effect of gravity on the seismic response of the large-scale container crane structure is analyzed by theoretical and simulation methods.Firstly,the mathematical model of single degree of freedom is established to theoretically analyze the influence of gravity second-order effect on the seismic response of the container crane.The container crane structure jumping mathematical model considering the second-order effect of gravity is established and analyzed,and an approximate description of the container crane jumping process is obtained.Secondly,the modal analysis and dynamic time history analysis of the container crane structure are carried out to evaluate the dynamic characteristics and seismic performance of the container crane structure.Finally,comparative study between seismic dynamic response characteristics of the container crane structures which considers the second-order effect of structural gravity and the seismic dynamic response characteristics not considering it are done so as to assess the impact of gravity second-order effects on the seismic response of large-scale container crane structures.(3)The weak parts of the seismic analysis of the container crane structure are taken into account and the structure is simplified,and a three-free numerical analysis model that can consider the second-order gravity effect of the container crane structure is established.Then,referring to the approximate calculation method of the building structure considering the second-order effect of gravity,the dynamic differential equation of the container crane structure considering the second-order effect of gravity is derived,which is used to simplify the analysis of the influence of the second-order effect of gravity on the seismic response of large-scale container crane structures.Finally,the feasibility of this method is verified by comparing with the finite element simulation results.(4)The factors influencing the seismic response of the container crane structures considering the second-order effect of gravity are analyzed.Starting from the influencing factors of the structure itself and further subdividing,three key parameters affecting the response results are analyzed.Finally,the sensitivity analysis of these three key parameters is carried out,and the most important factors that can affect the seismic response of the container crane structure considering the second-order effect of gravity are obtained.