焊接铝合金柱承载力研究

Experimental Research on Carrying Capacity of Welded Aluminium Alloy Compression Members

铝合金作为一种新型结构材料,在现代建筑中得到了越来越广泛的应用。国内目前关于挤压型材已经进行了大量研究[1],但有关焊接铝合金构件的研究很少。由于铝合金焊接后受焊接热影响较大,试件中除了产生残余应力,在焊缝附近的局部区域材料强度还将大大降低,该区域被称为热影响区(HAZ)。而对于钢结构,由于其热导率比铝材小得多[2],因此只有高强钢才可能产生强度降低的热影响区,而且其强度的降低没有铝合金显著,热影响区的宽度也比铝合金小得多。这将使得铝合金受压杆件的承载力研究变得更为复杂。为此,本文对贴脚焊工字型铝合金中心受压杆件进行了试验研究,并将试验结果同即将颁布的国家标准《铝合金结构设计规范》及《欧洲铝合金结构设计规范》(EC9)进行了比较。研究表明,通常情况下,对于贴脚焊构件,《规范》结果和试验结果吻合较好。

Aluminium alloy as a new type of structural material,becomes more and more widely used in modern architecture.Now much study is done on extruded aluminium alloy members[1],while little is done on welded ones.Aluminium alloy welding will induce residual stress,what's more,reduce the material strength significantly in a localized region,known as the heat-affected zone(HAZ) softening,which will normally not happen to structural steel except high strength steel,for which such a reduced strength zone may however occur,the strength is not so drastically reduced as for aluminium alloy and the width of the heat-affected zone is much smaller due to the difference in heat transfer.Thus,experimental study of longitudinally welded I-section aluminium alloy columns subjected to axial compress will be conducted.The test strengths will be compared with the design strengths obtained using code for design of aluminium structures(draft) and eurocode 9 for aluminium structures.Generally,the codes predict the strengths of the double T profiles with fillet welds columns well.