Study On Dynamic Response Of Cylindrical Reticulated Mega-structure Under Impact Load

The cylindrical reticulated mega structure is an important part of the huge reticulated structure and has many advantages,such as clear transmission line,various forms,convenient construction and so on.It is mainly used in public buildings.Such structures,in addition to being subjected to conventional loads,may also be exposed to explosion and impact.Once the structure collapses due to impact,it will cause serious consequences.In this paper,the dynamic response of the cylindrical reticulated mega structure under impact load is studied by numerical simulation.The failure mechanism and failure rule are studied by large-scale numerical analysis.The main contents are shown as follows.(1)Using ANSYS/ LS-DYNA modeling,the correctness and reliability of the numerical simulation method are verified by theoretical and experimental results.(2)In view of the impact load on the substructure,the whole deformation process of the substructure and the development of damage are investigated.The dynamic response mode of the the cylindrical reticulated mega structure is summarized as four types.The characteristics of each impact response model are analyzed by finite element simulation.In a large number of examples,it is found that the probability of collapse is very small when impact load is on the substructure.(3)In view of the impact load on main bearing structure,the whole deformation process of the substructure and the development of damage are investigated.The dynamic response mode of the the cylindrical reticulated mega structure is summarized as four types.ANSYS/ LS-DYNA is used for the finite element simulation to analyzethe characteristics of the impact response modes.By changing the parameters of impact mass,impact velocity,impact point position,roof load and so on,a large number of examples are analyzed for the impact load on the main bearing structure,and the effects of these parameters on the overall collapse of the structure are investigated.It is showed that the increase of roof loads and the decrease the raito of hian and span will increase the probability of collapse.(4)Combined with the failure mechanism and failure law of the cylindrical reticulated mega structure under the impact load,three kinds of protection design methods are put forward to prevent structural collapse under impact loads,such as light roof method,integral strengthening method and local strengthening method.Through numerical simulation,the effectiveness of the three methods is verified.