Free vibration characteristic of single-layer spherical aluminium alloy latticed shells

With the wide application and rapid development of the aluminum alloy structure in China, the insufficiency of study on its dynamic characteristic becomes increasingly prominent. Moreover, the free vibration characteristic is the research foundation of its dynamic characteristic. In order to study the free vibration characteristic of Kiewitt-6 and Kiewitt-8 (K6 and K8) aluminum alloy single-layer spherical latticed shells with gusset joints, large amount of finite element (FE) analysis was carried out using ANSYS. In the established models, various parameters including rise-span ratio, span, roof load, span thickness ratio, grid density and support boundary conditions were considered. Based on the FE results, the formula to estimate the fundamental frequency of single-layer spherical latticed shells was derived, without considering the effects of joint stiffness. Subsequently, by introducing the amplification factor, the formula of the fundamental frequency of aluminum alloy shells with gusset joints was proposed. Finally, the proposed formulae were validated against the experimental values of an actual shell. The theoretical values agreed well with the test results, indicating the proposed formulae had good accuracy.