Analysis On Response Of Tower Crane Structures Under Random Earthquake Excitations

With the development of building structures’design, which results in the appearance of many tower crane structures with a span of hundreds of meters. Earthquakes are common in China, Because of its big mounting height and high center of gravity, and the uneven distribution of mass and flexible features, So once tower crane suffered earthquake, huge loss is following,and secondary disasters will be caused by inefficient relief work. The calculation results of tower crane are inaccurate if we ignored the influence of the earthquake affected. Currently, research on the stochastic vibration effects is still in the exploratory stage, and neither theoretical analysis system nor design method is perfect. so it’s necessary to do some research for the response of stochastic vibration which provided an important reference for engineering practice. The main work of this paper is concluded as follows:1. A FEM (Finite Element Method) model of tower crane was built based on ANSYS. Stress distribution was showed through the static analysis. Then check the strength, stiffness and stability of tower crane requirements.2. Introduced the analyzing method of random seismic response of structure which including Stationary random seismic response analysis, the non-stationary random seismic response analysis and pseudo-excitation method. This paper adopt Du-xiuli Chen-houqun density model, and the model parameter values were listed which influenced by magnitude, epicentral distance. That provided a reference for parameter selection.3. Nature vibration characteristic of tower crane were obtained through the modal analysis, which provide a basis for the subsequent dynamics analyses. Adopting the method of response spectrum analysis, this paper calculated the seismic response of structure under different load effect combination. And then comparison the analysis result of crane stress and displacement.4. Based on the theory of random vibration, the dynamic response on tower crane under random seismic excitation was investigated. The input of earthquake ground motion is indicated by Duxiuli-Chenhouqun power spectral. The random seismic responses of structural’s force and displacement were researched under five different earthquake model input with uniform earthquake excitations method, The analysis reveals that the force of tower crane increase significantly under vertical seismic excitation than X-direction, Z-direction excitation have the greatest influence in tower body bending moment; the primary reason of tower arm fracture is vertical seismic action, too large seismic wave cause tower body capsized easily, and compared the results of response spectrum analysis and stationary random seismic response analysis. That provided an important reference for seismic design and analysis of tower crane.