Plate reinforced square hollow section X-joints subjected to in-plane moment

Abstract

The static test of 13 square hollow section (SHS) X-joints with different β and different types of plate reinforcement under in-plane moment in brace was carried out. Experimental test schemes, failure modes of specimens, moment-vertical displacement curves, moment-deformation of the chord, and strain strength distribution curves were presented. The effect of β and plate reinforcement types on in-plane flexural property of SHS X-joints was studied. Results show that punching shear of chord face disappears, brace material fracture appears and concave and convex deformation of chord decrease when either collar plates or doubler plates were welded on chord face. Moment-vertical displacement curves of all specimens have obvious elastic, elastic-plastic and plastic stages. As β increases, the in-plane flexural ultimate capacity and initial stiffness of joints of the same plate reinforcement type increase, but ductility of joints decreases. With the same β, the in-plane flexural initial stiffness and ultimate capacity of doubler plate reinforced joints, collar plate reinforced joints, and unreinforced joints decrease progressively. Thickness of reinforcement plate has no obvious effect on in-plane flexural initial stiffness and ultimate capacity of joints. As thickness of reinforcement plate increases, the ductility of reinforced X-joints decreases. The concave and convex deformation of every specimen has good symmetry; as β increases, the yield and ultimate deformation of chord decrease.

Keywords

failure analysis / square hollow section (SHS) X-joints / plate reinforcement types / in-plane flexural property / ultimate capacity / initial stiffness / strain strength distribution / ductility

References

[1] WardenierJHollow sections in structural application [M], 20112nd edNetherlands, Bouwen Met Staal: 1-10

[2] PackerJ A, WardenierJ, ZhaoX L, et al. Design guide for rectangular hollow section (RHS) joints under predominantly static loading (Second Edition). Comité International pour le Développement et l’Étude de la Construction Tubulaire (CIDECT), Verlag TÜV Rheinland. Cologne, Germany, 200915-35

[3] ChoK N, HaW I, JangC D. Ultimate strength of specially reinforced tubular joint with brackets [J]. Marine Structures, 1991, 4(1): 57-79

[4] ChooY S, LiangJ X, VegteG J. Static strength of collar plate reinforced CHS X-joints loaded by in-plane bending [J]. Journal of Constructional Steel Research, 2004, 60(12): 1745-1760

[5] ChooY S, VegteG J, ZettlemoyerN. Static strength of T-joints reinforced with doubler or collar plates. I: Experimental investigations [J]. Journal of Structural Engineering, ASCE, 2005, 131(1): 119-128

[6] VegteG J, ChooY S, LiangJ X, et al. . Static strength of T-joints reinforced with doubler or collar plates. II: Numerical simulations [J]. Journal of Structural Engineering, ASCE, 2005, 131(1): 129-138

[7] ShaoY-b, LieS-t, ChiewS-ping. Hysteretic performance of circular hollow section tubular joints with collar-plate reinforcement [J]. Journal of Constructional Steel Research, 2011, 67(12): 1936-1947

[8] FungT C, ChanT K, SohC K. Ultimate capacity of doubler plate-reinforced tubular joints [J]. Journal of Structural Engineering, ASCE, 1999, 125(8): 891-899

[9] FungT C, ChanT K, SohC K. Stress concentration factors of doubler plate reinforced tubular T joints [J]. Journal of Structural Engineering, ASCE, 2002, 128(11): 1399-1412

[10] ChooY S, LiangJ X, VegteG J, et al. . Static strength of doubler plate reinforced CHS X-joints loaded by in-plane bending [J]. Journal of Constructional Steel Research, 2004, 60(12): 1725-1744

[11] SohA-k, SohC-kiong. Stress analysis of axially loaded T tubular joints reinforced with doubler plates [J]. Computers & Structures, 1995, 55(1): 141-149

[12] HoonaK-h, WongL-k, SohA-kah. Experimental investigation of a doubler-plate reinforced tubular T-joint subjected to combined loadings [J]. Journal of Constructional Steel Research, 2001, 57(9): 1015-1039

[13] YinY, HanQ H, BaiL J, et al. . Experimental study on hysteretic behaviour of tubular N-joints [J]. Journal of Constructional Steel Research, 2009, 65(2): 326-334

[14] ShenW, ChooY-sang. Stress intensity factor for a tubular T-joint with grouted chord [J]. Engineering Structures, 2012, 35(2): 37-47

[15] ShaoY-b, ZhangJ-c, QiuZ-h, et al. . Strength analysis of large-scale multiplanar tubular joints with inner-plate reinforcement [J]. International Journal of Space Structures, 2009, 24(3): 161-177

[16] WoghirenC O, BrennanF P. Weld toe stress concentrations in multi-planar stiffened tubular KK joints [J]. International Journal of Fatigue, 2009, 31(1): 164-172

[17] RamachandraM D S, MadhaveA G, GandhiP, et al. . Structural efficiency of internally ring-stiffened steel tubular joints [J]. Journal of Structural Engineering, ASCE, 1992, 118(11): 3016-3035

[18] GandhiP, RaghaveG, RamachandraM D S. Fatigue behavior of internally ring-stiffened welded steel tubular steel tubular joints [J]. Journal of Structural Engineering, ASCE, 2000, 126(7): 809-815

[19] AhmadiH, MohammadA, ShaoY B. Parametric study and formulation of outer-brace geometric stress concentration factors i internally ring-stiffened tubular KT-joints of offshore structures [J]. Applied Ocean Research, 2012, 38(1): 74-91

[20] AhmadiH, MohammadA, ShaoY B. Chord-side SCF distribution of central brace in internally ring-stiffened tubular KT-joints: A geometrically parametric study [J]. Thin-Walled Structures, 2013, 70(3): 93-105

[21] LeeM M K, ParryA. Strength of ring-stiffened tubular T-joints in offshore structures-a numerical parametric study [J]. Journal of Constructional Steel Research, 1999, 51(3): 239-264

[22] LeeM M K, ParryA. Offshore tubular T-joints reinforced with internal plain annular ring stiffeners [J]. Journal of Structural Engineering, ASCE, 2004, 130(6): 942-951

[23] LeeM M K, ParryA. Strength prediction for ring-stiffened DT-joints in offshore jacket structures [J]. Engineering Structures, 2005, 27(6): 421-430

[24] ThandavamoorthyT S, MadhavaA G, SanthakumarA R. Behavior of internally ring-stiffened joints of offshore platforms [J]. Journal of Structural Engineering, ASCE, 1999, 125(11): 1348-1352

[25] WangW, ChenY-y, MengX-de. Behavior of thick-walled CHS X-joints under cyclic out-of-plane bending [J]. Journal of Constructional Steel Research, 2010, 66(6): 826-834

[26] WangW, ChenY-yi. Hysteretic behaviour of tubular joints under cyclic loading [J]. Journal of Constructional Steel Research, 2007, 63(10): 1384-1395

[27] ABAQUS.Standard user’s manual. Version 6.11: Vols. 1-3 [M], 2006, Hibbitt, Karlsson and Sorensen, Inc. USA