Experimental investigation and numerical simulation on welding residual stress of innovative double-side welded rib-to-deck joints of orthotropic steel decks

Abstract

An innovative double-side welded rib-to-deck (RTD) joint has been developed recently to enhance fatigue performance of orthotropic steel decks (OSDs) in steel bridges. The welding residual stresses (WRS) will lead to reduction in fatigue resistance of RTD joints in steel bridges. It is essential to study WRS and its distribution to estimate the fatigue resistance of innovative double-side welded RTD joints accurately. To investigate WRS caused by the double-side welding process, the experimental tests on four specimens of double-side welded RTD joints were carried out by means of longitudinal critical refraction (LCR) wave method. A sequentially coupled three-dimensional thermo-mechanical finite element (FE) analysis model was established to simulate the double-side welding process, and it was validated by the WRS results of experimental investigation. Then, the effects of welding parameters and geometric configuration of RTD joints on WRS and its distribution are analyzed by the validated numerical simulation. The results show a reasonable agreement between WRS simulation and the experimental data. WRS at the surface of weld seam and plate components is strongly affected by the welding speed, but comparatively weakly depends on the weld penetration rate, the assembly gap and the deck thickness.