Research On Continuous Strength Design Method Of H-section Aluminum Alloy Axial Compression Members

The Continuous strength method(CSM)is a design method based on section deformation ability and considering the strain hardening effect of materials.This method was first applied to the design of stainless steel members.Considering that the stress-strain curves of aluminum alloy and stainless steel are nonlinear curves,CSM is also applicable to the local buckling capacity of aluminum alloy members.This paper studies the application of CSM in H-section aluminum alloy axial compression members.The main research contents are as follows:(1)Material properties of 27 specimens were tested to obtain the elastic modulus,nominal yield strength,ultimate strength,yield strain,ultimate strain and stress-strain curves of 6061-T6 and 6063-T6 aluminum alloy for subsequent finite element model verification and further parameter analysis.(2)Experimental study on local stability of 12 H-section aluminum alloy axial compression stub columns was carried out.The load-axial compression curve,local stability bearing capacity and damage form of aluminum alloy stub column were obtained through the test.(3)Experimental study on overall stability of 12 H-section aluminum alloy axial compression long columns was carried out.The load-axial compression curve,load-Mid-span deflection curve,load-end angle curve,overall stability bearing capacity and damage form of aluminum alloy were obtained.(4)The local stability of axial compression stub column is analyzed by finite element software ABAQUS.The finite element software simulated the non-slender H-section aluminum alloy stub column model of 34 different ratio of section slenderness,and the stub column bearing capacity was compared with the bearing capacity results calculated by CSM,Chinese codes and European codes to verify the accuracy of CSM in predicting the local stability bearing capacity of the stub column.(5)The overall stability of aluminum alloy axial compression members ABAQUS studied by finite element software,including 170 H-section aluminum alloy long columns with different ratio of section slenderness and relative aspect ratio.The CSM equivalent initial imperfection amplitude and the linear formula of CSM imperfection coefficient and section flexibility coefficient are calculated by using the finite element model results,which are used to predict the overall stable bearing capacity of H-section aluminum alloy long column,and the predicted values of stable bearing capacity of long column are compared with the calculated values of Chinese code and European code formula to verify the accuracy of CSM in predicting the overall stability capacity of long column.