铝合金工形截面短柱轴压局部稳定试验研究

为研究铝合金工形截面轴压构件的局部稳定性能，对15根工程中常用大截面铝合金6061-T6和6063-T5轴压短柱试件进行试验研究，并对12组48个材性试样进行拉伸试验。研究了材料的力学性能、试件的局部几何初始缺陷、变形性能、局部屈曲荷载、轴压承载力等，并将试验结果与各国规范中设计方法计算结果进行对比。试验结果表明：铝合金6061-T6强度与普通钢材相当，但延性较差；铝合金挤压型材的局部几何初始缺陷很小，远小于规范中给定数值；板件宽厚比越大，局部屈曲发生越早，破坏时材料的强度越得不到充分发挥，但是局部屈曲后材料强度仍有较大的提高；翼缘和腹板之间存在相互作用；中国规范、欧洲规范、美国规范和澳大利亚/新西兰规范均低估了试件的轴压承载力，其中美国规范计算结果与试验结果最接近。因此，对于板件宽厚比大的试件，应充分利用其屈曲后强度，各国规范得到的承载力计算结果均较保守。

Experimental study on local buckling behavior of aluminum alloy columns under uniform compression

This paper presented an experimental study about the local buckling behavior of aluminum alloy I-columns, including 15 different stub columns under uniform compression and 12 groups (48 coupons) of tensile coupons. The aluminum alloys considered were 6061-T6 and 6063-T5. The mechanical properties of the materials, local imperfections, deformation behavior, local buckling capacity and ultimate loading capacity were studied. The test results were also compared with design methods from different design standards. The results show that aluminum alloy 6061-T6 has the same strength level as standard grades of steel but lower ductility, the local imperfections of the extruded columns are far below the requirements in the standards; with a greater width-to-thickness ratio, the plate is more likely to buckle and fail under a smaller stress level but there is still an increase in the post-buckling strength; the interaction between flanges and webs has an influence on the behavior of each plates; the Chinese, European, American and Australian/New Zealand standards underestimated the ultimate loading capacity of the columns and American standard gave more accurate results. Therefore it is recommended that the post buckling strength should be considered, especially for plates with great width-to-thickness ratio, the design methods in the above standards should be revised to give reasonable results.