Nonlinear Response Investigation Of The Single-Layer Reticulated Domes Under The Impact Load

Lattice shell structures are a new kind of rod-connected space structure.These new structures are widely applied to large-span domes.The members of the lattice shell are well distributed so that they bear forces in a more simply and effective way over traditional beam-column structures and truss structures.Lots of researches have been conducted over the lattice shell subjecting to the static load,the wind blow and the earthquake etc.These researches have paved a way for the prosperity of lattice shell.However the safety of the lattice structure subjected to impact loading should be payed attention to nowadays as the probability of accidents including terrorist attacks,falling air vehicles and so on increases.The main object of this article is to investigate the nonlinear responses of lattice structure subjected to concentrated impact loading.Factors such as the geometric and material nonlinearity,the contact condition and the boundary conditions are comprehensively considered for the analysis.In order to acquire a comprehensive cognition of the characteristics of the lattice shell response,a sum up of the relative fellow papers are made.The results of these papers are concluded to reflect the deformation response and the internal force response of the lattice shell.An one-at-a-time parametric analysis has been made on the lattice shell response.Among the many response outputs,the deformation response is the most important which embodies the damage severity of the lattice shell.As a result,an equivalent shell method and a direct method both based on the principle of energy conservation are proposed to acquire the simplified solution for the displacement of the lattice shell.Besides,global sensitivity analysis method is applied to computing the importance value of the parameters of the lattice shell to quantitatively investigate on the relative influence of the input factors on the outputs.At last,a revision technique is proposed for scaled-down models of the lattice shell to better simulate full-scale prototype.The technique is based on the similarity ratios deduced from dimension analysis and partial similitude method.The innovations of this paper are listed as follow: 1)An equivalent shell method and adirect method is proposed aimed at theoretically solving the ultimate displacement of the lattice shell.The advantage of the equivalent shell method is to shed light upon the relationship between the response values and the input variables,while the direct method provides a detailed information on the energy dissipation among the three rod types.These two methods are quite simple to use and serve as supplement for each other,and they provide a theory for the design of lattice shell crashworthiness.2)Apply the Global Sensitivity Analysis method to globally assess the impact of parameters on the response of the lattice shell,through computing the importance factors.These factors are more representative than the one-at-a-time factors.3)Provide a technique for the set-up of scaled-down models of the impacted lattice shell.The purpose of the technique is to make sure that the models’ results resembles that of the prototype which would otherwise be distorted by the strain-rate effects.