Research On Hysteretic Behavior Of Space Grid Structure Steel Triodetic Joint

Triodetic joint was originally in Canada in the middle of the 20 th century,is a kind of space grid structure joint which has simple form,low manufacturing cost,reasonable force,convenient construction and installation operation.The joints can be made of different materials such as steel,aluminum alloy and carbon fibre-reinforced polymer,adapt to the different curvature of the free-form surface space grid structure system,meet the requirements of high efficiency,light weight and assembly of node connection system in spatial grid architecture and it has been applied to a certain extent in large-span spatial grid structures in the fields of construction,coal,mining,environmental protection and chemical industry all over the world.But in Our country,this kind of node space structure system is seldom used.In view of the above background,this paper mainly carries out the following work:(1)In order to ensure the convenience of batch modeling,the geometric model of two different tooth shape triodetic joints is established by using the parameterization command,and imported into the general finite element software ABAQUS to establish the finite element model.Several nonlinear problems involved in joint simulation are considered,and the validity of the joint finite element model is verified.(2)By using the finite element software ABAQUS,the hysteretic behavior of the rectangular tooth triodetic joint under the action of low cycle reciprocating bending moment is simulated.The influence of different tooth width,tooth spacing,tooth height and hub diameter on the bending capacity,stiffness degradation and energy dissipation capacity of the joint is analyzed.It can be seen from the simulation results that when the tooth width and the tooth spacing are too large,the failure mode of the joint will change from the shear failure of the convex teeth to the failure caused by the yield of the slotted interval part,and the failure will occur when the hub body diameter is small,and the yield of the slotted and the central slotted interval part will lead to the failure.Selecting the reasonable joint detail size can avoid the weakening of the mechanical performance of the joint caused by the latter two failure modes.(3)The finite element software ABAQUS is used to simulate the hysteretic behavior of trapezoid tooth triodetic joint under the action of low cycle reciprocating bending moment,and the influence of different size parameters on the hysteretic performance of the joint is analyzed.Compared with the rectangular tooth triodetic joint,the third failure mode does not appear in the joint,but the joint will fail due to the too small tooth height and the large dislocation between the hub body and the rod end insert.This failure mode also has an obvious impact on the mechanical performance of the joint.