Ultrasonic and FEM residual stress measurement in dissimilar St37–St52 welding

Abstract

Numerous industries, like the military, the oil and gas industry, etc., rely heavily on dissimilar welding. The welding process leaves the structure with a variety of defects, such as residual stress, that degrade its performance and static and fatigue properties. Consequently, weld residual stress must be accurately measured. In this study, ultrasonic and finite element techniques are developed to assess the residual stress in dissimilar St37/St52 welding. In addition, hole-drilling technique is employed to confirm FEM and ultrasonic data. Probe fixture is designed and built for ultrasonic stress measurement, and the acoustoelastic coefficient is measured in St37 and St52. In welding finite element analysis, the Goldak model is used as the heat source, the Brekstad model is employed as the heat loss, and the Dflux subroutine is developed to apply the heat source to the weld line using the sedimentary method. The FEM and ultrasonic data are in good correlation with the hole drilling results (maximum error of 9%). The findings indicate that there is a high degree of concordance between the data gathered by FEM and ultrasonic technique (with error less than 1.75% at the weld zone).

Assessment of Drilled GFRPCs' behavior under Combined-Static Loading via Mechanical and AE Techniques

“…SHM techniques are divided into two categories: active techniques and passive approaches. In passive methods such as acoustic emission(AE), the source (such as damage) is inside the specimen; therefore, sensors detect the damage's response to external loadings [5]. Active approaches, including ultrasonic, utilize an external source, such as a wave, to evaluate the damage [6].…”