【摘要】 为研究结构工程中高强铝合金轴心受力构件的局部稳定性能，对7个7075-T6铝合金H型截面短柱开展了轴心受压试验，测量了7075-T6铝合金的材料力学性能和试件的局部几何初始缺陷，分析了试件的破坏形态、局部屈曲承载力、极限承载力．试验结果表明，7075-T6铝合金材料平均名义屈服强度达到536 MPa；试件翼缘与腹板的平均局部几何初始缺陷幅值分别为0.29%和0.04%，属于《铝合金建筑型材第1部分：基材》(GB/T 5237.1—2017)中的高精级构件．采用基于板件应变的“应变反转法”与基于板件位移的“N-w~2法”确定了构件的局部屈曲荷载，板件宽厚比越大，构件局部屈曲应力与极限应力越小，同时局部屈曲应力与极限应力的比值也越小，说明对于宽厚比大的板件，其局部屈曲后强度提升明显，设计中应予以利用．将构件的极限承载力的试验结果与各国规范计算值进行了对比，现行《铝合金结构设计规范》(GB 50429—2007)和欧洲规范(EN 1999-1-1:2007 Eurocode 9)均采用“有效厚度法”对铝合金板件屈曲后强度进行设计，美国规范(The Aluminum Design Manual 2015)基于全截面计算，通过材料强度折减，以考虑局部屈曲引起的截面承载力的降低．3个规范计算值与试验结果的平均比值分别为0.840、0.824和0.923，表明现行国家规范和欧洲规范均对7075-T6高强铝合金轴压构件的极限承载力的计算偏于保守，美国规范的计算结果更加准确．更多还原

【Abstract】 Seven H-section stub column tests were conducted to investigate the local buckling performance of 7075-T6 high-strength aluminum alloy extruded H-section stub columns.The material properties,initial geometric imperfections,failure modes,critical local buckling strengths,and load carrying capacities of the specimens were analyzed.The nominal yield strength of the 7075-T6 aluminum alloy was approximately 536 MPa,and the mean values of the local geometric imperfection amplitude ratios of the width of flanges and webs were 0.29%and 0.04%,respectively,which could be classified as high-precision according to GB/T 5237.1—2017.The critical local buckling load was determined using the strain reversal and N-w~2 methods,which are based on the measured surface strain and lateral deflections of plates,respectively.The critical local buckling stress,ultimate strengths of the specimens,and the ratios of local buckling stress to ultimate strength declined as the width to thickness ratios of the plates increased,indicating that it is reasonable to utilize post buckling strengths of sections in structural design.Based on these results,current design standards,i.e.,Chinese code for the design of aluminium alloy structures GB50429—2007,European EN 1999-1-1:2007(EC9),and American Aluminum Design Manual 2015(ADM)were evaluated.GB 50429—2007 and EC9 standards predict local buckling resistance by using the effective thickness method,whereas ADM predicts the local buckling resistance of aluminum alloy members through strength reduction of the whole cross-section.The mean values of strength ratios for GB 50429—2007,EC9,and ADM were 0.840,0.824 and 0.923,respectively,indicating that GB 50429—2007 and EC9 offer conservative predictions for ultimate strengths of 7075-T6 high-strength aluminum alloy H-section stub columns,whereas ADM is relatively accurate.更多还原