Response And Axial Residual Load Capacity Of 6061-T6 Aluminum Alloy Tubes Under Lateral Impact

In the design process of architecture and bridge,the joint action of various types of loads needs to be considered.In recent years,the explosion of chemical plants and the collision of ships with bridges have made structural engineers to pay more and more attention to the study of impact and explosion loads.On the other hand,most bridges are designed to be conservative,so that they can still be used normally after a small impact,when the residual capacity becomes the focus of engineers’ attention.Aluminum alloy is one of the materials often used in large span structures because of its excellent mechanical properties.The study of the response of aluminum alloy round tubes under impact loading and the residual load capacity after impact is of great significance for explosion-proof and impact resistance of large span structures.The yield strength of 6061-T6 aluminum alloy is close to that of Q235 steel,which is used in civil engineering applications.In view of this,in this paper,drop hammer impact tests,numerical simulation of lateral impact and simulation analysis of the residual bearing capacity after impact were carried out with it as the research object.The details of the study are as follows.(1)Experimental study of lateral impact of aluminum alloy circular tube with solid support at both ends16 sets of lateral impact tests on aluminum alloy round tubes were carried out,and the dynamic response process was described in detail;the deformation mechanism of "tri-plastic hinge" of aluminum alloy round tubes was revealed,and 4 failure modes were obtained;the effects of span,wall thickness,tube diameter,impact location,impact momentum and impact kinetic energy on the dynamic response of aluminum alloy round tubes were parametrically analyzed.(2)Numerical simulation study of lateral impact of aluminum alloy round tube with solid support at both endsRoom-temperature quasi-static tensile tests were carried out to fit and determine parameters A,B,n of the J-C dynamic constitutive model of 6061-T6 aluminum alloy,and a finite element model of the lateral impact of aluminum alloy round tube was established based on ANSYS/LS-DYNA,and its accuracy was verified;the typical dynamic response of aluminum alloy round tube under lateral impact was obtained,and5 failure modes were identified;the effects of span,wall thickness,tube diameter,impact location,impact momentum and impact kinetic energy were parametrically analyzed.(3)Study on the axial residual load bearing capacity of aluminum alloy round tube after impact with solid support at both ends.The calculation model of axial residual bearing capacity of aluminum alloy circular tube after lateral impact was established,and the parametric analysis of axial residual bearing capacity was carried out to investigate the effects of span,wall thickness,tube diameter,impact location,impact momentum and impact kinetic energy.The prediction formula of the residual bearing capacity ratio k was proposed by fitting and its accuracy was verified.