FORMULATION OF STRESS-STRAIN RELATIONS OF STRUCTURAL ALUMINUM ALLOYS AND OF RESIDUAL STRESSES INDUCED BY JOINING

Abstract

In this research, tensile tests are carried out for the structural aluminum alloys 6061-T6, 6N01-T5 and 5083-O. Application of a probability-statistical approach to the test results shows that the Young's modulus and the strain-hardening parameter are expressed by a normal distribution and a lognormal one, respectively. The relations between stress and strain are formulated, using the values corresponding to the 5% probability of not being exceeded for the Young's modulus and the strain-hardening parameter. Furthermore, tensile tests are carried out for butt connections fabricated by MIG welding and FSW, and he relations between stress and strain are formulated for MIG welds and FSW joints. Based on the measured residual strains, the residual stresses are formulated with a rectangular distribution.