Resistance of welded aluminum alloy plate girders to shear and patch loading

Aluminum alloys are used in a variety of structural engineering application s, such as transportable and lightweight bridges, due to their high strengt h-to-weight ratio and durability. However, the heat of welding may reduce t heir strength significantly and necessitate the inclusion of strength reduc tion factors in design calculations. Theoretical procedures for predicting ultimate shear and patch resistance, which include material strength reduct ion factors to allow for welding, are now incorporated in BS8118, the code of practice for aluminum structures, and EC9, the Eurocode of practice for aluminum structures. However, when compared with available test results, th eoretical predictions in accordance with BS8118 and EC9 appear unduly conse rvative. Experimental and theoretical studies of the behavior and strength of welded aluminum alloy plate girders, subjected to shear and patch loadin g, are reviewed and discussed. Theoretical predictions of the ultimate resi stance, based on modified and developed theories, are compared and show con sistent and improved correlation with experimental results.