WELDING INSPECTION -STEELS CONTENTS PAGE

International Journal of Steel Structures, 2015

In this paper, effectiveness of reinforcing fillet welds in preventing cracking in roots of partial joint penetration welds is investigated. The method used for this investigation includes finite element modeling and a micromechanical model of crack initiation. Base plate connections of three wide flange sections with various fillet weld dimensions are modeled. A novel method is proposed for idealization of the partial penetration weld geometry. The accuracy of the finite element model and the cracking initiation prediction method are verified based on test results. It is observed that, for each column section, utilizing fillet welds larger than a certain size shifts the crack initiation location from the partial penetration weld root to the column flange, which delays cracking considerably. The aforementioned minimum size of the reinforcing fillet welds depends mainly on thickness of the column flange, and also on the depth of the cross section.

Welding in The World, 2022

This paper presents the influences of the irregularity "insufficient penetration welding" on the fatigue strength based on experimental and numerical investigations. For this purpose, the fatigue strength of partial penetration butt welds of mild steel (S355) with different non-welded gaps were subjected to fatigue loading. Three different planned gap dimensions (h = 4, 6, 8 mm) at one-sided (Y-seam) and two-sided (DY-seam) partial penetration butt welds were analysed. The results were obtained on a small-scale test specimen with a steel plate thickness of t = 20 mm, without axial and angular misalignment. For the numerical effective notch stress approach, regression formula for efficient analysis of stress concentration factors was determined. The results show that butt joints which are not fully penetrated on one or both sides, and which were previously not permissible for welded joints subject to fatigue loading, can be evaluated in the future on the basis of these investigations. Keywords Fatigue • Partial penetration butt weld • S355 • Mild steel • Y-seam • DY-seam • Fatigue strength • Finite element model • Meta model • Effective notch stress approach • ISO 5817 • Weld quality Abbreviations Material, test specimen and state parameter f y Yield strength in [MPa] S355 Mild steel (S355) S355J2 + N, EN 10025 with a nominal yield strength of f y = 355 MPa t Plate thickness in [mm] Recommended for publication by Commission XIII-Fatigue of Welded Components and Structures.

ARCHIVE: Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 1989-1996 (vols 203-210), 1992

The measurement of weld penetration using a front-face sensor has been an important issue in welding automation. The fundamental problem is to find a measurable front-face parameter that can adequately represent the weld penetration. In this paper, both the front-face average weld depression depth (a novel weld geometrical parameter) and the weld width are selected as possible representations of full penetration in GTA welding. Two types of sensitivities of front-face weld geometry, with respect to variations in welding conditions and with respect to control variables, are proposed as criteria for determination of promising parameters. Sensitivity calculation of experimental data shows that the front-face weld width is not promising while the average front-face weld depression depth is. This conclusion is also confirmed by a specific experiment and statistic models.

Welding is defined by the American Welding Society (AWS) as a localized coalescence of metals or non-metals produced by either heating of the materials to a suitable temperature with or without the application of pressure, or by the application of pressure alone, with or without the use of filler metal. Welding techniques are one of the most important and most often used methods for joining pieces in industry. Any information about the shape, size and residual stress of a welded piece is of particular interest to improve quality. In the recent years, the welded joints become the integral part of assemblies used in the industries. In fact in piping industries welded joints are crucial and prone to different types of loadings. Hence in such applications most of the failures are due to the failing of the welded joints. Hence a modern computational approach based on finite element analysis for strength assessment has been used in this dissertation work.

International Journal of Fatigue, 2017

Fillet welded connections are most commonly used for construction of engineering structures that are often subjected to various forms of cyclic loading in service. There exist two potential fatigue failure modes, i.e., weld root cracking through weld throat and weld toe cracking into plate thickness. The former should be prevented at design stage through a proper weld sizing. However, due to difficulties in determining stress concentration at weld throat, existing fatigue design rules, particularly on weld sizing, are largely empirical and often result in excessive conservatisms, leading to oversized welds. As structural lightweighting becomes increasingly important, there is an increasing demand for more quantitative fatigue-based fillet weld sizing criterion. By taking advantage of a comprehensive set of fatigue test results on load-carrying fillet-welded cruciform joints and associated analytical developments reported by Xing et al. (2016), an analytical weld throat stress model taking into account of weld penetration and joint misalignments is presented in this paper for determining critical weld size beyond which weld throat failure become unlikely. Then, it is shown that a weld sizing criterion can be analytically developed and expressed as a function of weld penetration and joint misalignments, which are shown to agree well with the large amount of test data reported by Xing et al. (2016), including a systematic validation by means of a logistic regression method on the same test data. As a result, the present developments provide both analytical and experimental basis for achieving quantitative weld sizing so that weld throat fatigue failure mode can be effectively prevented with a clearly defined confidence level without the need of over-sizing.

An HAZ hardness criterion is used to predict the minimum size fillet welds that can be deposited on certain steels without preheat BYB. A. GRAVILLEAND J. A. READ