An Analysis Of The Anti-collapse Of Nature Museum Of Shanxi Province

Because of the advantages of large construction space and reasonable overall stress,the reticulated shell structure has become the fastest-growing and most widely used space structure in the past half century.However,due to the sensitivity of the single-layer reticulated shell to initial defects,we have to pay more attention to its stability.The stress situation of the reticulated shell structure is complicated,and the load action it receives is often random.The structure gradually produces damage of rods and nodes under long-term load,and it is easy to burst collapse accidents under occasional loads.The outer spherical shell structure of Nature Museum of Shanxi Province is a typical single-layer spherical shell structure.As the largest single-layer spherical shell structure in China at the time of construction,its structural design has a high degree of redundancy.In order to determine its actual collapse resistance,this paper will consider the material nonlinearity and geometric nonlinearity of the structure to analyze the collapse resistance of the reticulated shell structure of the Nature Museum of Shanxi Province under strong snow load and strong earthquake and analyze the reliability of the structure.This paper takes the actual engineering Nature Museum of Shanxi Province as the research background and numerically simulates the structure based on the ANSYS finite element analysis software.It systematically studies the collapse resistance of the structure,the weak parts of the structure and the reliability of the structure under heavy snow load,the main research work and important conclusions are as follows:(1)The collapse of the reticulated shell structure was simulated by static nonlinear buckling analysis to evaluate the anti-collapse performance of the reticulated shell structure under strong snow load.The most unfavorable snow load distribution is determined,and the ultimate load of the structure under different snow load distribution conditions and the weak parts of the structure under the snow load are obtained;(2)By analyzing the elastoplastic time-history of the structure under different combinations of earthquake directions,it is determined that the structure has good seismic performance under rare earthquakes.In order to further determine the dynamic ultimate load of the reticulated shell structure,the incremental dynamic analysis method(IDA method)is used,that is,the seismic wave amplitude is continuously increased for time-history analysis to determine the dynamic acceleration when the reticulated shell structure collapses;(3)Considering the material nonlinearity and geometric nonlinearity,and integrating various factors,the reliability analysis of the reticulated shell structure of the Nature Museum of Shanxi Province under the most unfavorable snow load distribution conditions was carried out.It is determined that under this analysis condition,the distribution function type of the structural deflection is approximately distributed according to the extreme value I type.The calculated reliability index of the structure meets the target reliability under the first-level security level.