Forcing Property Study Of Joint Area For Large Span Beam-truss Composite Structure

The composite truss-beam structure is one that is somehow new, and it is provided with easy maintaining, reasonable cost and high carrying capacity. There is plenty of this bridge being built on foreign countries, thus the study of it is still in the stage of development in our country. With the development of the structure design theory and the construction technology, the study of this structure is wildly carrying on in our country. For the joint of this structure is the critical region that guarantees the truss and beam working consistently. The study of the joint gradually becomes a representative subject of such structure.This thesis reviewed the development and stated the current situation of beam-truss composite structure in foreign countries and domestic. And the stress distribution, the force transmission mode and the load-displacement curve of the joint has been calculated by ANSYS. The finite element model including nonlinear contact of the joint was set up to study the stress and the strain of the real joint precisely. Then this paper analyzed the out comings of the finite element analysis which indicated the stress and strain distributions discipline and the load-displacement curve of the joint. The joint model that is scaled by the way of equal carrying capacity was executed. The result of the model test shows that the joint is still intact after exerted600t on it; the load-displacement curve remain an oblique straight line that means the joint is still in the stage of elastic. Afterwards, analysis of the two results is carried out, which shows that these two results meet each other well.According to the analysis, the PBL is effective and reliable. The entire node has high stiffness, high carrying capacity and good crack resistance, which show that joint construction is reasonable and meets the design requirements of truss-beam composite structure in the aspect of reliability, security. Meanwhile this article accumulates some data and experiences for the truss-beam composite structure especially the joint.