Membrane residual stresses and compressive behaviour of laser-welded stainless steel T-sections

This paper reports experimental and numerical investigations into the membrane residual stresses and compressive behaviour of laser-welded stainless steel T-sections. An experimental programme was firstly conducted on eight T-sections and included tensile coupon tests, membrane residual stress measurements, initial local geometric imperfection measurements and sixteen stub column tests. On the basis of the measured data, a new membrane residual stress predictive model was proposed for laser-welded stainless steel T-sections. Following the experimental programme, a numerical modelling programme was performed, with finite element models developed and validated against the test results and then employed to perform parametric studies to generate additional numerical data over a wide range of cross-section dimensions. The obtained test and numerical data were used to evaluate the relevant local buckling design rules specified in the European code and American specification. The evaluation results revealed that (i) the codified slenderness limits were generally accurate when used for cross-section classification of laser-welded stainless steel T-sections in compression and (ii) both design codes resulted in slightly conservative and scattered cross-section compression resistance predictions.