Stability of single-layer reticulated domes with initial imperfection to members

Based on commercial finite element software ANSYS and self-compiled pre-processing and post-processing programs, the stability of single-layer reticulated domes which include and do not include the effect of initial bending of members are compared. Using the random imperfection mode method, more than 2800 geometrically and materially nonlinear analyses for the Kiewitt single-layer reticulated domes which include the effect of initial bending of members are carried out. The law of the influence of random variables of bending angle and amplitude on the stability of reticulated domes is obtained. The applicability of conformable imperfection mode method and the eigenvalue imperfection mode method of analyzing the effect of initial bending of members on the ultimate loads is demonstrated. The modified conformable imperfection mode method is proposed which is applicable to calculate the ultimate load of single-layer reticulated domes including the effect of initial bending of members. Resorting to the modified conformable imperfection mode method, more than 300 geometrically and materially nonlinear analyses for the Kiewitt single-layer reticulated domes including the effect of initial bending of members are conducted. The results show that the initial bending of members can decrease the ultimate load of each shell and change the buckling mode and the development of plasticity. If the maximum allowable bending is 1/1000 of the length of the member, the maximum decrease in the ultimate load of shell is more than 5%, and it is more than 10% if the maximum allowable bending is 2/1000 of the length of the member.