The 8-node iso-parametric thin shell element was employed in the study of stress concentrations in the welded tubular “K” joint. Element equilibrium equations were derived using isoparametric formulation based on thin shell theory. After assembly, the resulting system equations were solved using existing fortran programs. Numerical experiments were conducted to isolate and locate ideal gap(positions) for the two braces of the “K” joint. The nominal stresses were calculated from which stress concentration factors were obtained. The resulting stress concentration factors were presented both as tables and as figures. A good agreement between our solutions and those for model joints in the literature is good and acceptable. It was found that the wider apart the brace spacing is, the weaker the strength of the joint. It was also found that the best location for the braces occurs when the stress level changes sign either from positive to negative or vice versa at a critical sampling point.
Cite this paper
P. Jiki, "Location Results for Brace Spacing in Gap Tubular “K” Joints Using FEM," Modern Mechanical Engineering, Vol. 3 No. 1, 2013, pp. 50-54. doi: 10.4236/mme.2013.31007.
 J. G. Kuang, A. B. Potuin and R. D. Leick, “Stress Concentration in Tubular Joints,” Offshore Technol Conference, Houston, 4 May 1972, pp. 6-15.
 A. B. Potuin, J. G. Kuang, R. D. Leick and J. L. Kahlich, “Stress Concentration in Tubular Joints,” SPE Journal, Vol. 17, No. 4, 1977, pp. 287-299.
 M. S. Gibstein, “Parametric Stress Analysis of T-Joints,” Offshore Steel Seminar, Cambridge, 1978, pp. 3-26.
 A. C. Wordsworth and G. P. Smedley, “Stress Concentrations at Unstiffened Tubular Joints,” Offshore Steel Seminar, Cambridge, 1978.
 S. Walbridge and A. Nussbaumer, “Probablistic Fatigue Analysis of Shop and Field Treated Tubular Truss Bridges,” Journal of Construction Steel Research, Vol. 64, No. 2, 2008, pp. 156-166. doi:10.1016/j.jcsr.2007.06.001
 A. Schumacher, and A. Nussbaumer, “Experimental Study on the Fatigue Behaviour of Welded Tubular K Joints for Bridges,” Journal of Engineering Structures, Vol. 28, No. 5, 2006, pp. 745-755.
 A. K. Soh and C. K. Soh, “Hot-Spot Stresses of Tubular K Joints Subjected to Combined Loading,” Journal of Construction Steel Research, Vol. 26, No. 2-3, 1993, pp. 125-140. doi:10.1016/0143-974X(93)90032-N
 J. C. Paul, Y. Makins and Y. Kurobane, “Ultimate Resistance of Unstiffened Multi Planar Tubular T T and K K Joints,” Journal of Structural Engineering, ASCE, Vol. 120, No. 10, 1994, pp. 2853-2870.
 J. A. Parker, “Concrete Filled HSS Connections,” J. of Structural Engineering, ASCE, Vol. 120, No. 3, 1995, pp. 458-467.
 P. N. Jiki, “Prediction of Stress Concentration Factors in Un-lapped Square Hollow ‘K’ Joints by the Finite Element Method,” Nigerian Journal of Technology, Vol. 25, No. 1, 2006, pp. 5-14.
 P. N. Jiki, “Stress Analysis of Un-lapped Rectangular Hollow ‘K’ Joints by the Finite Element Method,” Botswana Journal of Technology, Vol. 17, No. 2, 2009, pp. 46-53. (Botswana)
 E. Hinton and D. R. J. Owen, “Finite Element Programming,” Academic Press, London, 1977, pp. 95-110.