Study On Mechanicalperformance Ofa Large-Span Irregular-Shapedand Double-Layer Latticed Shelloftianjin Polar Ocean World

Latticed shells are curved models of space frames, and the mechanical properties of the structures were more and more paid attention to. Based on FEM analysis software ANSYS, a large-span, double-layer and irregular-shaped latticed shell of Tianjin Polar Ocean World is analyzed as an example. The static characters, temperature effect, vibration characters and seismic response spectra, time-history analysis of the structure were studied in the thesis.Firstly, the thesis introduced the general situation of project, structure style, calculation model, static load cases (including dead load, live load and wind load) and combination, then discussed the support reactions, member stresses and nodes displacements of the structure based on static analysis by ANSYS. The result shows that the space action is distinct, structural stiffness is enough, stress distribution is regular, so the structure has good static mechanical performance.Secondly, the thesis described the conception of temperature effect, studied the effect of annual average temperature on the mechanical performance. Under the action of temperature effect, the change of horizontal force and displacement is large, the change of vertical force and member stress is little. Combining temperature effect and dead load and live load, the designs of support reaction, member stress and displacement of the struction has met the design requirement.Thirdly, the paper researched the vibration characters of the latticed shell by the modal analysis, so as to analyze the rationality of the structure system and determine the interrupt of vibration modes. Then, the paper studied the dynamic response of the structure under the action of multi-directional seismic action by means of response speturm method, analyzed the distribution of member dynamic-force. The paper combined seismic action and other loads, and then studied the aseismatic performance of the structure. Under earthquake actions, most members’dynamic-force is much smaller than those static-force, the aseismic design of the structure has met the design requirement, it has good aseismatic performance.Finally, the time-history analysis of the structure was studied under the multi-directional uniform excitation and the multi-support excitation, which only consider travelling-wave effects. The conclusion is that the result of time-history analysis matches the result of seismic response spectra well in the statistical sense, the response spectrum analysis reflects the dynamic performance of the latticed shell enough. The dynamic performance under travelling-wave effects is smaller than that under uniform excitation, so travelling-wave effect has little influence on the design of the latticed shell.