Research On Dynamic Failures Of Latticed Shell Structures Under Typhoon Load

Long-span structures are mostly used in large-scale public buildings such as sports venues, warehouses, and exhibition centers, and they are of great importance. Once getting broken, it can bring significantly negative influence to social production and people’s daily life. Meanwhile, typhoons attack our country annually, destroying lots of long-span structures. So, it’s of important significance to research on the dynamic failures of long-span structures under typhoon load.Based on the Yan Meng typhoon model, the key parameters of typhoon are confirmed. According to the tropical cyclone observations of the Pacific Northwest between 1949 and 2014, the optimal probability models of the key parameters of typhoon are confirmed by simulation circle method. By using random sampling method,10000 groups of typhoons are simulated. Matched the maximum simulated wind speed with the maximum speed of the tropical cyclone observations, the typhoon wind profile exponent is obtained.The characteristics of wind pressure on surface of latticed shell structures and shell structures with opening at the top in normal wind field and typhoon wind field are analyzed by FLUENT. The results show that the characteristics of wind pressure on surface of shell structures in normal wind field and typhoon wind field are similar, but the pressure coefficient of surface in typhoon wind field is larger than that in normal wind field. When the ratio between height and span equals 1/8, the pressure mainly appears negative in both wind fields, and the top area gets the maximum negative pressure. Normal to the movement direction of the wind, the pressure coefficient of edge area is larger than that of center area.Using harmonic wave superimposing method, the wind speed in the time domain of the nodes on surface of shell structure is simulated by MATLAB. In normal wind field, the Davenport wind speed spectrum is chosen, and in typhoon wind field, the Von Karman wind speed spectrum is chosen correspondingly. Contrast to the goal wind speed spectrum, the validity of the two spectra in both wind fields is proved.By analyzing the dynamic behaviors of shell structure and suspendome in normal wind field and typhoon wind field, the conclusion that both the average and the standard deviation of displacement in typhoon wind field are larger than in normal wind field. Meanwhile, the maximum displacement located in the node that connecting upper shell and stay bar under wind load.The criteria of dynamical failure of latticed shell structure under typhoon load are proposed by focusing on the two indexes of the maximum displacement, and ratio of plastic members, and the criteria of dynamical failure of suspendome under typhoon load were proposed by focusing on the three indexes of the maximum displacement, ratio of plastic members and whether the cables are slack. The rationality and applicability of the criteria are proved through analysis of examples.