Residual Stress Evaluation in Dissimilar Welded Joints Using Finite Element Simulation and the L_(CR) Ultrasonic Wave

摘要

Subsurface stresses in welded structures increase the likelihood of fatigue cracks and environmental induced material degradation. The ability to evaluate stresses at the surface as well as in the interior of welded structural members would substantially increase the accuracy of structure life estimation. The longitudinal critically refracted (L_(CR)) wave is a bulk longitudinal mode that travels within an effective depth underneath the surface. It may be used to detect in-plane subsurface stresses in the structures. This paper presents a three dimensional thermo-mechanical analysis to evaluate welding residual stresses in dissimilar plate-plate joint of AISI stainless steel 304 and Carbon Steel A106-B type. After finite element simulation, the residual stresses were evaluated by L_(CR) ultrasonic waves. Finally the results of two methods were compared and verified by hole-drilling method. This paper introduces a combination of "Finite Element Welding Simulation" and "Ultrasonic Stress Measurement using the L_(CR) Wave" which is called as "FEL_(CR)". The capabilities of FEL_(CR)". The capabilities of FEL_(CR) in residual stress measurement are confirmed here. And also this paper evaluates residual stresses of dissimilar welded joints by LCR ultrasonic waves. It has been shown that predicted residual stress from three dimensional FE analyses is in reasonable agreement with measured residual stress from LCR method and also the results of both are verified with hole-drilling experimental measurements.