Axial Loads Steel - Polyurethane Composite Pipe Mechanical Properties

The main purpose of this paper is to research on the ultimate bearing capacity of polyurethane filled steel tube(PFST) under axial load. The polyurethane filled steel tube structures have a lot of advantages,such as high strength,light quantity, good anti-seismic performance ,good shape,fast strike , simple construction and so on, consequently, they have been used widely in the engineering practice in recent years.However, the current theory research mostly lay particular stress on steel sandwich structure of steel and polyurethane. Polyurethane filled steel tube has not been launched research. Therefore, it is very necessary to study the mechanical properties of polyurethane filled steel tube under axial load.(1)This paper collects the test data on the stain deformation and ultimate bearing capacity,describe the change of figure and the failure patterns of the specimens.(2)The influence of the different hoop coefficient and slenderness ratio of axial polyurethane filled steel tube on the load-deflection curve character and all the course of work are discussed.(3)A 3-D nonlinear finite element model is established in the paper.The constitutive model of steel tube and polyurethane elastomers is selected. They are modeled by using plasticity modeled which is isotropic elasticity and plasticity model with a Von Mises yield surface.In the model, considering the adhesive property between the steel tube and polyurethane elastomers is good, the elements share their nodes.(4)The finite element method is applied to the mechanic analysis in this paper on the former analysis.Mechanisms of polyurethane filled steel tube subjected axial loading conditions are analyzed based on the numerical method.(5)Through verification test we know finite element method adopted in the constitutive relation model is appropriate, yield criterion is reasonable, and the adhesive property between polyurethane and steel tube are good.The simplified calculating formula for ultimate bearing capacity is presented by the regressive analysis.