Study On Static Performances Of A New Type Of Sectional Connection System With Box Section Bar

In the box section grid structure,the connection between the rod and the node is mainly welded.The existing assembly connection scheme has many problems,such as the lack of structural practicability and geometric adaptability,the weakening of the bar resistance,the complex process,the difficulty in construction and the high manufacturing cost.In view of the research status of box section assembly connection system,a new type of box section bar assembly connection system was proposed in this research group.In order to facilitate the application of single-layer latticed shell structures,the static performance of the assembly connection system is studied and analyzed in depth.Firstly,based on the existing expernmental results,the non-linear contact analysis technology is compared and validated.Then,the finite element contact analysis model of the new connection system is established by using the fine partition technology of the finite element software ABAQUS.Then,three kinds of connection systems with different number of bolts are selected to study their mechanical properties under four basic internal forces:pure shear,pure bending,axial tension and axial compression,focusing on the relative displacement,stress distribution,plastic strain development and failure characteristics of the connection surface;and then the main components of the three connection systems under combined internal forces such as compression-bending,tension-bending,bending-shear,compression-shear and tension-shear are studied.For mechanical properties,the elastic and plastic limit outsourcing curves are drawn,and the approximate calculation formulas of the corresponding curves are obtained by fitting.Then,based on the internal force characteristics of single-layer reticulated shell members,considering the main internal force forms such as pure bending,axial tension,axial compression,compression-bending combination and tension-bending combination,the orthogonal experimental analysis is carried out to study the effects of bolt pretension,end plate thickness,bolt diameter,bolt spacing and flange contact area on the static strength of the connection system,and reveal that the static strength of the new connection system varies with each other.The law and trend of parameter change.Furthermore,the results of numerical simulation are summarized,and the proposed design ideas and checking methods for the static strength design of the new type of connection system are given.Finally,the main research results of this paper are summarized,and future research prospects are put forward.