Effect of Vibration during Welding on the Fatigue Strength of Structural Steel Weldments

Abstract

During repair welding of steel bridge under service load, vibration occurs due to the dynamic loads like wind and vehicles, etc. However, the effect of vibration during welding on the fatigue strength of weldments is not yet clearly understood. In this paper, the effect of vibration during welding on the fatigue strength of structural steel weldments was investigated in order to improve reliability in the repair welded joints of steel bridge. The base material used in this investigation was SM 490A steel of weldable grade. Flux Cored Arc Welding (FCAW) process was used to fabricate the single ‘V’ butt joints. Welding was performed on the steel under the mechanical vibration of given frequency. The applied frequency was resonant frequency. Also, weldments under no vibration during welding were prepared. Fatigue tests were conducted using a servo hydraulic controlled 50tonf capacity UTM with a frequency of 5Hz under constant amplitude loading. Effect of vibration during welding on the fatigue strength of weldments was analyzed in detail.

Vibration assisted welding processes and their influence on quality of welds

“…Workpieces were clamped on a table vibrating longitudinally with the help of an electrodynamic vibrator and welded using manual metal arc welding. Rutile coated mild steel electrodes were used, and the welding current, voltage, energy input, arc length a vibration of workpiece; 15,16,44,[46][47][48][49][50][51][52][53][54][55] b weld pool oscillation; [56][57][58][59]61,[63][64][65][66][67][68][69][70][71][72][73][74][75] c molten droplet oscillation using pulsed current; [76][77][78][79] d oscillation of welding arc; [80][81][82][83][84][85][86][87][88][89][90][91][92] e vibration of electrode…”

“…The fatigue strength of weldment made of SM 490A steel of weldable grade was improved only slightly with mechanical vibrations of workpieces during FCAW. 48 The experimental set-up had a mechanical vibration apparatus consisting of rotary vibrator, programmable logic controller, sensor and analyser. The experiment was conducted at the resonant frequency of 60 Hz.…”