超500MPa级高强钢承压型螺栓连接承载力试验研究
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摘要
高强度螺栓承压型连接的承载力来源于钢板与螺栓的接触行为,承载力的发展伴随着螺栓孔周围材料的应力集中和塑性变形。普通钢延性好,可以克服螺栓孔周围应力集中的不利影响,充分发展承压承载力。随着强度增高,钢材的延性降低、变形能力下降,应力集中的不利影响将更突出。因此,需对高强钢构件的承压型连接进行研究。该文以Q550D、Q690D和Q890D三种国产高强钢共制作50组单螺栓试件,其中24组双剪切面试件、16组单剪切面试件,6组孔径变化试件,并与4组Q345B单螺栓试件进行了对比。研究表明:高强钢仍具备足够的延性,能克服应力集中的不利影响,连接破坏模式与普通钢无明显差异;剪切面数和螺栓孔径对不同高强钢承压强度影响较小,但单剪切面的试件更容易出现螺栓剪断,降低连接的延性,限制承压承载力的利用。基于已有试验的结果与中国现行标准《钢结构设计规范》比较,发现螺栓连接的钢板承压强度设计取值偏保守,对于超500 MPa高强钢可适当提高其设计值,以充分利用高强度钢材的材料强度,合理减少螺栓数量。
In bearing-type bolted connections, the load-bearing capacity is established by the contact between the plate and the bolts. The load-bearing capacity develops with growing bolt hole elongation. Due to the existence of bolt holes, stress concentration exists near the bolt holes. For normal-strength steel, the large ductility can ease the adverse effect of such stress concentration, which ensures the full development of strength.High-strength steel has reduced ductility with lower elongation at bolt holes. The effect of stress concentration may be conspicuous. Therefore, the strength of bolted connections made of high-strength steel should be studied.This paper uses three types of high-strength steel, Q550D, Q690D and Q890D, to produce 24 groups of single-bolt double-shear connections, 16 groups of single-shear connections, 6 groups of connections with changing bolt holes and another 4 groups of connections made of normal-strength steel. The results show that the ductility of high strength steel can also ease the effect of stress concentration. No significant difference is found compared with normal-strength steel. It is also found that bolt shear failure occurs more easily in single-shear connections with increasing steel grade, which reduces the ductility of the whole connection. Based on the existing experimental results, increased design strength in the current Chinese Code for the Design of Steel Structures is suggested, which will make better use of the material strength of high-strength steel and reduce the number of bolts.
In bearing-type bolted connections, the load-bearing capacity is established by the contact between the plate and the bolts. The load-bearing capacity develops with growing bolt hole elongation. Due to the existence of bolt holes, stress concentration exists near the bolt holes. For normal-strength steel, the large ductility can ease the adverse effect of such stress concentration, which ensures the full development of strength.High-strength steel has reduced ductility with lower elongation at bolt holes. The effect of stress concentration may be conspicuous. Therefore, the strength of bolted connections made of high-strength steel should be studied.This paper uses three types of high-strength steel, Q550D, Q690D and Q890D, to produce 24 groups of single-bolt double-shear connections, 16 groups of single-shear connections, 6 groups of connections with changing bolt holes and another 4 groups of connections made of normal-strength steel. The results show that the ductility of high strength steel can also ease the effect of stress concentration. No significant difference is found compared with normal-strength steel. It is also found that bolt shear failure occurs more easily in single-shear connections with increasing steel grade, which reduces the ductility of the whole connection. Based on the existing experimental results, increased design strength in the current Chinese Code for the Design of Steel Structures is suggested, which will make better use of the material strength of high-strength steel and reduce the number of bolts.
引文
[1]李国强,王彦博,陈素文,等.高强度钢结构研究现状及其在抗震设防区应用问题[J].建筑结构学报,2013,34(1):1―13.Li Guoqiang,Wang Yanbo,Chen Suwen,et al.State-of-the-art on research of high strength structural steels and key issues of using high strength steels in seismic structures[J].Journal of Building Structures,2013,34(1):1―13.(in Chinese)
[2]施刚,朱希.高强度结构钢材单调荷载作用下的本构模型研究[J].工程力学,2017,34(2):50―59.Shi Gang,Zhu Xi.Study on constitutive model of high-strength structural steel under monotonic loading[J].Engineering Mechanics,2017,34(02):50―59.(in Chinese)
[3]王朋,陈海波,张会武,等.螺栓连接对基础非均匀沉降输电塔的影响研究[J].工程力学,2015,32(10):209―219.Wang Peng,Chen Haibo,Zhang Huiwu,et al.Effect of bolt joint on the behaviour of transmission tower with non-uniform settlement[J].Engineering Mechanics,2015,32(10):209―219.(in Chinese)
[4]GB 50017―2017,钢结构设计规范[S].北京:中国计划出版社,2017.GB 50017―2017,Code for design of steel structures[S].Beijing:China Planning Press,2017.(in Chinese)
[5]Puthli R,Fleischer O.Investigations on bolted connections for high strength steel members[J].Journal of Constructional Steel Research,2001,57(3):313―326.
[6]EN 1993-1-8 Eurocode3:Design of steel structures-Part1-8:Design of joints[S].Brussels:European Committee for Standardization,2005.
[7]Mo?e P,Beg D.High strength steel tension splices with one or two bolts[J].Journal of Constructional Steel Research,2010,66(8/9):1000―1010.
[8]Mo?e P,Beg D.A complete study of bearing stress in single bolt connections[J].Journal of Constructional Steel Research,2014,95:126―140.
[9]Mo?e P.Bearing strength at bolt holes in connections with large end distance and bolt pitch[J].Journal of Constructional Steel Research,2018,147:132―144.
[10]Kim H J,Yura J A.The effect of ultimate-to-yield ratio on the bearing strength of bolted connections[J].Journal of Constructional Steel Research.1999,49(3):255―269.
[11]Aalberg A,Larsen P K.Bearing stregnth of bolted connections in high strength steel[C].Copenhagen:Nordic Steel Construction Conference Committee,2001:859―866.
[12]Aalberg A,Larsen P K.The effect of steel strength and ductility on bearing failure of bolted connections[C].Portuguesa:The Third European Conference Committee,2002:869―878.
[13]AISC.Specifications for Structural Steel Buildings.ANSI/AISC 360-10[S].Chicago:American Institute of Steel Construction,Inc,2010.
[14]Kamtekar A G.On the bearing strength of bolts in clearance holes[J].Journal of Constructional Steel Research,2012,79:48―55.
[15]石永久,潘斌,施刚,等.高强度钢材螺栓连接抗剪性能试验研究[J].工业建筑,2012,42(1):56―61.Shi Yongjiu,Pan Bin,Shi Gang.Experimental study on high strength steel-plate-bolted connections under shear force[J].Industrial Construction,2012,42(1):56―61.(in Chinese)
[16]潘斌,石永久,王元清.Q460等级高强度钢材螺栓抗剪连接孔壁承压性能有限元分析[J].建筑科学与工程学报,2012,29(2):48―54.Pan Bin,Shi Yongjiu,Wang Yuanqing.Finite element analysis of bolted connection in Q460 grade high strength steels under static shear[J].Journal of Architectural and Civil Engineering,2012,29(2):48―54.(in Chinese)
[17]石永久,潘斌,王元清.高强度钢材螺栓连接孔壁承压性能研究及设计建议[J].青岛理工大学学报,2013,34(1):24―32.Shi Yongjiu,Pan Bin,Wang Yuanqing.Investigation and proposed design rules on bolted connections for high strength steel[J].Journal of Qingdao Technological University,2013,34(1):24―32.(in Chinese)
[18]Wang Yanbo,Lyu Yifan,Li Guoqiang.Behavior of single bolt bearing on high strength steel plate[J].Journal of Constructional Steel Research.2017,137:19―30.
[19]GB/T 228.1―2010,金属材料拉伸试验第1部分:室温试验方法[S].北京:中国标准出版社,2010.GB/T 228.1―2010,Metallic material-tensile testing-Part1:Method of test at room temperature[S].Beijing:China Standard Press,2010.(in Chinese)
[20]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part A:results[R].Eurocode 3 Editorial Group,1988.
[21]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part B:evaluations[R].Eurocode 3 Editorial Group,1988.
[22]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part C:Test data[R].University of Technology Aachen,Institute for Steel Construction,1988.
[23]施刚,朱希.国产高强度结构钢设计指标和可靠度分析[J].建筑结构学报,2016,37(11):144―159.Shi Gang,Zhu Xi.Design indexes and reliability analysis of domestic high-strength structural steels[J].Journal of Building Structures,2016,37(11):144―159.(in Chinese)
[2]施刚,朱希.高强度结构钢材单调荷载作用下的本构模型研究[J].工程力学,2017,34(2):50―59.Shi Gang,Zhu Xi.Study on constitutive model of high-strength structural steel under monotonic loading[J].Engineering Mechanics,2017,34(02):50―59.(in Chinese)
[3]王朋,陈海波,张会武,等.螺栓连接对基础非均匀沉降输电塔的影响研究[J].工程力学,2015,32(10):209―219.Wang Peng,Chen Haibo,Zhang Huiwu,et al.Effect of bolt joint on the behaviour of transmission tower with non-uniform settlement[J].Engineering Mechanics,2015,32(10):209―219.(in Chinese)
[4]GB 50017―2017,钢结构设计规范[S].北京:中国计划出版社,2017.GB 50017―2017,Code for design of steel structures[S].Beijing:China Planning Press,2017.(in Chinese)
[5]Puthli R,Fleischer O.Investigations on bolted connections for high strength steel members[J].Journal of Constructional Steel Research,2001,57(3):313―326.
[6]EN 1993-1-8 Eurocode3:Design of steel structures-Part1-8:Design of joints[S].Brussels:European Committee for Standardization,2005.
[7]Mo?e P,Beg D.High strength steel tension splices with one or two bolts[J].Journal of Constructional Steel Research,2010,66(8/9):1000―1010.
[8]Mo?e P,Beg D.A complete study of bearing stress in single bolt connections[J].Journal of Constructional Steel Research,2014,95:126―140.
[9]Mo?e P.Bearing strength at bolt holes in connections with large end distance and bolt pitch[J].Journal of Constructional Steel Research,2018,147:132―144.
[10]Kim H J,Yura J A.The effect of ultimate-to-yield ratio on the bearing strength of bolted connections[J].Journal of Constructional Steel Research.1999,49(3):255―269.
[11]Aalberg A,Larsen P K.Bearing stregnth of bolted connections in high strength steel[C].Copenhagen:Nordic Steel Construction Conference Committee,2001:859―866.
[12]Aalberg A,Larsen P K.The effect of steel strength and ductility on bearing failure of bolted connections[C].Portuguesa:The Third European Conference Committee,2002:869―878.
[13]AISC.Specifications for Structural Steel Buildings.ANSI/AISC 360-10[S].Chicago:American Institute of Steel Construction,Inc,2010.
[14]Kamtekar A G.On the bearing strength of bolts in clearance holes[J].Journal of Constructional Steel Research,2012,79:48―55.
[15]石永久,潘斌,施刚,等.高强度钢材螺栓连接抗剪性能试验研究[J].工业建筑,2012,42(1):56―61.Shi Yongjiu,Pan Bin,Shi Gang.Experimental study on high strength steel-plate-bolted connections under shear force[J].Industrial Construction,2012,42(1):56―61.(in Chinese)
[16]潘斌,石永久,王元清.Q460等级高强度钢材螺栓抗剪连接孔壁承压性能有限元分析[J].建筑科学与工程学报,2012,29(2):48―54.Pan Bin,Shi Yongjiu,Wang Yuanqing.Finite element analysis of bolted connection in Q460 grade high strength steels under static shear[J].Journal of Architectural and Civil Engineering,2012,29(2):48―54.(in Chinese)
[17]石永久,潘斌,王元清.高强度钢材螺栓连接孔壁承压性能研究及设计建议[J].青岛理工大学学报,2013,34(1):24―32.Shi Yongjiu,Pan Bin,Wang Yuanqing.Investigation and proposed design rules on bolted connections for high strength steel[J].Journal of Qingdao Technological University,2013,34(1):24―32.(in Chinese)
[18]Wang Yanbo,Lyu Yifan,Li Guoqiang.Behavior of single bolt bearing on high strength steel plate[J].Journal of Constructional Steel Research.2017,137:19―30.
[19]GB/T 228.1―2010,金属材料拉伸试验第1部分:室温试验方法[S].北京:中国标准出版社,2010.GB/T 228.1―2010,Metallic material-tensile testing-Part1:Method of test at room temperature[S].Beijing:China Standard Press,2010.(in Chinese)
[20]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part A:results[R].Eurocode 3 Editorial Group,1988.
[21]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part B:evaluations[R].Eurocode 3 Editorial Group,1988.
[22]Snijder H H,Ungermann D,Stark J W B,et al.Evaluation of test results on bolted connections in order to obtain strength functions and suitable model factors Part C:Test data[R].University of Technology Aachen,Institute for Steel Construction,1988.
[23]施刚,朱希.国产高强度结构钢设计指标和可靠度分析[J].建筑结构学报,2016,37(11):144―159.Shi Gang,Zhu Xi.Design indexes and reliability analysis of domestic high-strength structural steels[J].Journal of Building Structures,2016,37(11):144―159.(in Chinese)