The Research On Finite Element Analysis Model Of Tubular Joints Truss

Steel tubular truss is a kind of structures which can combine the function and the appearance and the economic benefit of buildings perfectly. Its stress characteristics is variety and its components can be arranged flexibly,it is also one kind of building structures which have the strongest adaptability and the biggest variation of structure form. Tubular joints become the most common joints in the steel tubular structure because of its simple appearance and simple construction and clear force path. Under the loads, no matter in the elastic phase or plastic phase, it shows a feature which different from hinge joints and rigid joints, this feature called semi-rigid has a significant effect to the stability of the structure.This paper based on the domestic and international researches, used the circular steel tubular plane truss and space truss as an example, begun with necessity of considering semi-rigid joints in engineering design. With the help of the ADINA program, establish the beam finite element analysis model with beam element and multidimensional finite element analysis with beam element and shell element. Through the calculations of the analysis model, discuss the effects of the semi-rigid joints on the bearing capacity of structural stability. The paper mainly includes the following contents:By establishing the finite element analysis model of plane truss and space truss respectively with the beam element, analyzed the whole force process. Considered the joints hinge and rigid separately when establish the model. In order to obtain the force-displacement curve, simulated the failure mode of analysis structures by numerical value. The results show that, no matter plane truss or space truss, no matter considered the nonlinear material or not, there is a very big space of stability bearing capacity between the hinge joints and rigid joints.By establishing the multidimensional finite element analysis model of plane truss and space truss respectively with the beam element and shell element, analyzed the whole force process. The results of the analysis proved the necessity of considering joints semi-rigid, shows that the link nature of joints related to the nonlinear material.Research the influencing factors to the joint stiffness, inspect the effects for the structural stable bearing capacity from those factors by single parameter analysis method. The results show that the link nature between chords and webs of tubular joints truss related to the geometric parameters of joints: If the diameter-thick of main pipe ratio or the thickness ratio or diameter ratio between main pipe and secondary pipe are smaller, the joints are closer to the rigid joints, conversely, are closer to the hinge joints. Usually, it is between hinge and rigid, slightly closer to the latter.Finally, against the deficiency of this research, this paper expounds the next plan of research and prospect.