Study On Impact Resistance Of Shell Type Large Opening Floor Lattice Shell

The most common form of spatial structure is the reticulated shell.The so-called reticulated shell structure is a spatial structure rule with specific surface structure.For the sustainable economic development,the large-span reticulated shell structure has been widely used in construction engineering.At the same time,the reticulated shell structure is vulnerable to greater impact,the impact load time is short and the peak value is large,which will cause serious damage and cause very serious adverse impact on people’s psychology.The numerical algorithm can be used to study the impact resistance of reticulated shell structures,so as to continuously improve computer technology.In view of the fact that the span of reticulated shells studied by scholars in the field of impact resistance is not enough to meet the needs of today’s people,and the research is limited to single-layer latticed shells,which is not enough to support the current social demand for reticulated shells.In this context,the impact resistance of long-span reticulated shells is systematically studied in this paper:1.Understand the basic concepts of finite element software and impact,and the failure characteristic index of reticulated shells.This paper introduces the basic theory of impact analysis of ANSYS / LS-DYNA,defines the types of elements and material characteristics,and puts forward the basic assumptions,numerical analysis of shell double-layer reticulated shell simulation analysis.2.The influence of collision location and physical characteristics on the failure mode of reticulated shell is studied.In this paper,the rules of changing the failure mode of reticulated shell structure due to the change of impact position and physical characteristics of the impact object are studied,and the failure mode of reticulated shell structure is summarized,and the kinetic energy of the impact object is absorbed.The qualitative relationship between the impact location and the material properties is discussed.3.This paper studies the design,analysis method and structural requirements of reticulated shell with large openings in the background of the project of Chinese culture exhibition center.The opening will affect the bearing capacity of the reticulated shell.At present,the research on the reticulated shell is aimed at the reticulated shell without opening,and the research on the design method and requirements of the unclosed structure has not been completed.In this paper,we study the influence of openings on the static,stability,dynamic characteristics and dynamic response bearing capacity of large-scale open double-layer reticulated shells and reticulated shells without openings.By comparing the internal strength and deformation of reticulated shells with and without holes,the deformation of reticulated shells with and without holes is strengthened,and the design method and structural requirements of reticulated shells with holes are determined,which provides a reference for similar work in the future.4.Taking the beam element model and refined shell element model of the shell double-layer reticulated shell structure as examples,the size and load characteristics of the impact object are determined,and the impact object model is established,which is ready for the later impact simulation analysis.5.The calculation model of impact response of reticulated shell structure is established.The failure mode of reticulated shell structure under load is defined.The dynamic response characteristics of each failure mode are analyzed,and the failure mechanism is studied.The damage process of the whole collapse of the grandstand and stage area is as follows: local depression generation,local depression propagation and expansion,depression connection,depression hole breaking.The main reason is that the kinetic energy and the reduced position energy obtained from the impact of the structure are not enough to provide the energy consumed by the collapse.6.For the construction site of the scaffold installation and the erection of the operating frame do a simple description,and use the finite element software MIDAS gen to simulate the structure.