Parametric evaluation of the stress concentration factors in T-butt welded connections Gerardo Terán ⇑ , Apolinar Albiter, Ruben Cuamatzi-Meléndez Instituto Mexicano del Petróleo, Eje central Lázaro Cárdenas 152, Col. San Bartolo Atepehuacan, México, DF CP 07730, Mexico article info Article history: Received 18 July 2012 Revised 17 April 2013 Accepted 20 June 2013 Available online 17 August 2013 Keywords: Stress concentrations factors T–butt welded connection Grinding proﬁles abstract A methodology to evaluate the stress concentration factors (SCFs) in the grinded regions of T–butt welded connections under bending load is presented in this research work. Grinding was done to remove crack- ing material at the weld toe the connections. For the analysis, 2D plane stress conditions and three- dimensional ﬁnite element models were built to evaluate the SCFs for both types of welding connections. For the parametric study, different grinding proﬁles were proposed in order to study the SCFs at different critical points of the grinding proﬁles: edge of the grinding, bottom of the grinding and at the weld toe. It was found that the SCFs for the T welded connection are in function of the grinding angle and the amount of material removed in the regions of interest. And the 2D models over estimate the SCFs values for the critical points of the connections. The higher SCFs, where those located at the edge of the grinding. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction T–butt welded connections are extensively used in a huge vari- ety of engineering structures, such as offshore marine structures, ships, and pressure vessels. The welded connections are generally subjected to bending, tension and combined fatigue loads, result- ing in the development of cracks-like defects, which are very com- mon in welded joints. The defects can be gas pores, poor penetration of the weld, undercutting at the weld toe, etc., result- ing in stress concentrations by the crack-like defects, which are generally located at the weld toe, for different weld geometry pro- ﬁles [1]. But the stress concentrations and/or damage regions can be eliminated by grinding the cracking or damaged region at the weld toe of the structures, as crack defects generally starts at the weld toe [2]. Fatigue failure is likely to occur in regions with high SCFs, but as mentioned above, fatigue can be mitigated by grinding the crack- ing region. But in order to maintain structural integrity, the grind- ing depth must be as low as possible and at the same time it must eliminate all the cracking material. Therefore, it is very important to evaluate the SCFs for different grinding proﬁles and depths in or- der to establish limit values criteria for grinding depths and pro- ﬁles in the most critical regions of the structures. Several research works have been performed on the determina- tion of the SCFs under plane stress conditions of T welded connec- tions, with different grinding angles and weld toe radius [3–6], under tension and bending loading. The research work has also been focused on the evaluation of the SCFs in 3D conditions for both types of loads [3,4,7,8]. But research work is still needed on the development of parametric analysis for the evaluation of the SCFs for the T–butt welded connections. This with 3D ﬁnite ele- ment models, by varying the grinding angle for different grinding proﬁles. The results can be used to establish grinding criteria for grinding depths and grinding proﬁles for T and butt welded con- nections used in the construction of marine structures. Therefore, a parametric study of the SCFs, for different grinding conditions, at the weld toe, is performed in this research work. 2. Two dimensional ﬁnite element modeling of the T–butt welded connections The ﬁnite element method has been extensively used for anal- ysis the SCFs in different types of tubular connections used for the construction of ﬁxed platforms [9–11,1] used in the oil and gas industry. 2D ﬁnite element models of T-welded connections [12,13] and butt-welded connections [14] have shown the reliabil- ity of the ﬁnite element method for the analysis of the SCFs of welded connections. Therefore, in this research work, the ﬁnite ele- ment method is used for the analysis of the SCFs for the welded connections. Consequently, two dimensional ﬁnite element models of T–butt welded connections were created. For the T-welded connection, the following welded and grind- ing proﬁles were analyzed: a typical T-welded connection with no grinding and angle variation, different weld beads, different welding radius, different grinding depths for a U-shape grinding proﬁle and grinding depths ﬁlled with welding. And for the butt- 0141-0296/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.engstruct.2013.06.031 ⇑ Corresponding author. Tel.: +52 55 91758103. E-mail addresses: gteran@imp.mx (G. Terán), aalbiter@imp.mx (A. Albiter), rcuamatzi@imp.mx (R. Cuamatzi-Meléndez). Engineering Structures 56 (2013) 1484–1495 Contents lists available at ScienceDirect Engineering Structures journal homepage: www.elsevier.com/locate/engstruct