Numerical and experimental analysis of thermal-vibration stress relief for welded structure

Welded DH36 structures with high stiffness are widely used in marine engineering. Because of the high stiffness and high natural frequency of these structures, vibration stress relief (VSR) has very limited effects on them. To improve the VSR effectiveness, a novel method as thermal-vibration stress relief was proposed. The transversal and longitudinal stress decreased by 22.6% and 6.7% in a typical VSR treatment, while they were reduced by 41.3% and 43.6% in a TVSR at 150 ℃. The effect of TVSR was obviously better than VSR. Experiments and finite element method (FEM) were employed to analysis the mechanism of TVSRV. The rise of temperature can increase the vibration amplitude of the structure in non-natural frequencies, decrease yielding strength of the materials and consequently improve the effects of VSR.