Strength of aluminium members containing local transverse welds

Abstract

High strength aluminium alloys when welded suffer a local loss of strength due to the development of heat-affected zones (HAZ). The influence of such localized strength losses on the structural behaviour of aluminium members is studied using a numerical technique. Attention is given to the representation of the nonlinear stress—strain behaviour of aluminium, in particular, its representation in a form suitable for incorporation into numerical processes. Two finite element programs, previously developed for use with steel frame structures, have been modified to incorporate the special features of the aluminum problem. Results are presented for a selection of examples to illustrate the severity of the HAZ effect on the load carrying capacity of structural members. The theoretical predictions have been verified by comparison with bending tests on 5 nonwelded and 22 welded 7019 aluminium beams. Generally good agreement was found between the theoretical predictions and experimental results for all the tests.