Behaviour and ultimate tensile strength of partial joint penetration groove welds

Abstract

Partial joint penetration groove welds may be used in columns, for example, when it is not necessary to develop the full tensile capacity of the cross section. Also, where it is not feasible to make a full joint penetration groove weld because welding can be done from one side only, the strength of a partial joint penetration groove weld may be adequate. Limited experimental data have shown that the strength of partial penetration welds are proportional to their areas.A series of 75 tests on 25 mm thick, grade 300W and grade 350A steel plates, with welds made with matching electrodes and with 20–100% penetration, were conducted. The overall behaviour, the effects of percent penetration, plate strength, and the eccentricity of the load were investigated. The inherent ductility of the welds allows lateral deflections and straining to take place so that eccentrically loaded welds are as strong as concentrically loaded welds. The strength of welds is greater than the strength of the plate multiplied by the percent penetration and increases with the increasing lateral restraint that occurs with decreasing penetration. Design equations and resistance factors, based on weld strengths at least equal to the percent penetration multiplied by the ultimate tensile resistance of the plate, are proposed. Recommendations for fabrication are presented. Key words: behaviour, groove weld, limit states, partial joint penetration, strength, resistance factor, tension, ultimate.