钢—混组合梁翼缘有效宽度研究
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摘要
钢—混凝土组合结构是在钢结构和钢筋混凝土结构基础上发展起来的一种新型结构。近年来,钢—混凝土组合结构应用实践表明,它兼有钢结构和混凝土结构的优点,具有显著的经济效益和社会效益,适合我国基本建设的国情,将成为结构体系的重要发展方向之一。
在组合梁结构中,混凝土板作为钢梁翼板与钢梁共同工作,由于混凝土板中剪应变和剪应力的影响,混凝土板截面远离钢梁腹板部分的纵向位移滞后于离钢梁腹板较近的部分,混凝土板截面钢梁腹板附近部分的应力大于远离钢梁部分的应力,这种称为剪力滞效应的现象使得按初等梁理论计算的组合梁挠度和应力并不准确,偏于不安全。有效宽度概念直观的反映了剪力滞效应对组合梁承载能力和刚度的影响,在各国规范中广泛引用这一概念。混凝土板翼缘有效宽度是组合梁计算中非常重要的截面特征量,它的取值直接影响组合梁的承载力和挠度计算是否准确。影响钢—混组合梁混凝土板翼缘有效宽度的因素有宽跨比、荷载性质、沿桥跨方向变化、混凝土板厚、钢梁屈服强度、混凝土强度等级等。各国规范对有效宽度取值的规定因计算方法、设计理念和有效宽度问题本身的复杂性而相差较大。国内外针对组合梁翼缘有效宽度的研究,弹性分析居多,我国规范规定的有效宽度值也是基于弹性分析的结果,而组合梁实际承载力因塑性阶段的内力重分布,有效宽度也随之提高,使用弹性阶段的混凝土板翼缘有效宽度值容易产生较大的误差。因此研究弹性和塑性状态下各因素对组合梁混凝土板翼缘有效宽度影响具有重要意义。
本文基于有限元理论和程序对弹性阶段和塑性阶段下影响混凝土板翼缘有效宽度的因素进行了参数分析。根据弹性分析结果用回归方法提出了组合梁混凝土板翼缘有效宽度公式,并根据塑性发展程度对弹性状态公式进行修正;就我国规范与其它国家规范对钢—混组合梁混凝土板翼缘有效宽度规定进行了比较和分析,并与本文提出的公式进行比较,根据分析结果,提出了合理建议。
Steel-concrete composite structure is a newly structure type based on reinforced concrete structure and steel structure. Lately, engineering practices indicate this structural type both has the advantage of reinforced concrete structure and steel structure .Because of its significant economic and social effect, Steel-concrete composite structure develops to one of the most important structural type.
In a composite section, the concrete slab acting as a flange in the composite girder. The shear strain and stress in the concrete slab causes the longitudinal displacement in the parts of the slab remote from the webs lag behind that near the webs and the normal stress in the parts of the slab near the grid webs bigger than that remote from the webs. This phenomenon, termed shear-lag, can result in an incorrect calculation of the displacement and extreme fiber stresses when using only the elementary theory of beam bending. The effective width concept has been introduced, widely recognized, and implemented into different codes of practice around the world as a simplified practical method for design and evaluation of structural strength and stiffness while accounting for shear-lag effects indirectly. In the theory of steel-concrete composite beams, the effective width of concrete slab is a very important parameter of the section. Its value influences the bearing capacity and vertical deflection of the beam directly. There are many factors influence it, such as width-span ratio of the composite beam, form of the loads, concrete slab depth, concrete strength, and steel's yielding strength. Each code implements different ideas and approaches for specifying effective width, and they varied greatly .most of the research of this point based on elastic in plastic phase, because of redistribution of stress, the effective width enhanced. Both In elastic phase and plastic phase the effective width adopted by the codes is inclined to less than the actual effective width. Study how the factors influence the effective width in elastic phase especially in plastic phase has significant meaning.
A parametric study was conducted based on finite-element methodology to find the truth that how the factors above influence the slab effective width. Regressive equation based on the elastic data was proposed and revised in plastic phase. The Chinese code refers to Steel-concrete composite structure's effective width was compared and analyzed among other countries and equations proposed by author. Then some advice on the effective width can be applied to the analysis and design of Steel-concrete composite structure.
在组合梁结构中,混凝土板作为钢梁翼板与钢梁共同工作,由于混凝土板中剪应变和剪应力的影响,混凝土板截面远离钢梁腹板部分的纵向位移滞后于离钢梁腹板较近的部分,混凝土板截面钢梁腹板附近部分的应力大于远离钢梁部分的应力,这种称为剪力滞效应的现象使得按初等梁理论计算的组合梁挠度和应力并不准确,偏于不安全。有效宽度概念直观的反映了剪力滞效应对组合梁承载能力和刚度的影响,在各国规范中广泛引用这一概念。混凝土板翼缘有效宽度是组合梁计算中非常重要的截面特征量,它的取值直接影响组合梁的承载力和挠度计算是否准确。影响钢—混组合梁混凝土板翼缘有效宽度的因素有宽跨比、荷载性质、沿桥跨方向变化、混凝土板厚、钢梁屈服强度、混凝土强度等级等。各国规范对有效宽度取值的规定因计算方法、设计理念和有效宽度问题本身的复杂性而相差较大。国内外针对组合梁翼缘有效宽度的研究,弹性分析居多,我国规范规定的有效宽度值也是基于弹性分析的结果,而组合梁实际承载力因塑性阶段的内力重分布,有效宽度也随之提高,使用弹性阶段的混凝土板翼缘有效宽度值容易产生较大的误差。因此研究弹性和塑性状态下各因素对组合梁混凝土板翼缘有效宽度影响具有重要意义。
本文基于有限元理论和程序对弹性阶段和塑性阶段下影响混凝土板翼缘有效宽度的因素进行了参数分析。根据弹性分析结果用回归方法提出了组合梁混凝土板翼缘有效宽度公式,并根据塑性发展程度对弹性状态公式进行修正;就我国规范与其它国家规范对钢—混组合梁混凝土板翼缘有效宽度规定进行了比较和分析,并与本文提出的公式进行比较,根据分析结果,提出了合理建议。
Steel-concrete composite structure is a newly structure type based on reinforced concrete structure and steel structure. Lately, engineering practices indicate this structural type both has the advantage of reinforced concrete structure and steel structure .Because of its significant economic and social effect, Steel-concrete composite structure develops to one of the most important structural type.
In a composite section, the concrete slab acting as a flange in the composite girder. The shear strain and stress in the concrete slab causes the longitudinal displacement in the parts of the slab remote from the webs lag behind that near the webs and the normal stress in the parts of the slab near the grid webs bigger than that remote from the webs. This phenomenon, termed shear-lag, can result in an incorrect calculation of the displacement and extreme fiber stresses when using only the elementary theory of beam bending. The effective width concept has been introduced, widely recognized, and implemented into different codes of practice around the world as a simplified practical method for design and evaluation of structural strength and stiffness while accounting for shear-lag effects indirectly. In the theory of steel-concrete composite beams, the effective width of concrete slab is a very important parameter of the section. Its value influences the bearing capacity and vertical deflection of the beam directly. There are many factors influence it, such as width-span ratio of the composite beam, form of the loads, concrete slab depth, concrete strength, and steel's yielding strength. Each code implements different ideas and approaches for specifying effective width, and they varied greatly .most of the research of this point based on elastic in plastic phase, because of redistribution of stress, the effective width enhanced. Both In elastic phase and plastic phase the effective width adopted by the codes is inclined to less than the actual effective width. Study how the factors influence the effective width in elastic phase especially in plastic phase has significant meaning.
A parametric study was conducted based on finite-element methodology to find the truth that how the factors above influence the slab effective width. Regressive equation based on the elastic data was proposed and revised in plastic phase. The Chinese code refers to Steel-concrete composite structure's effective width was compared and analyzed among other countries and equations proposed by author. Then some advice on the effective width can be applied to the analysis and design of Steel-concrete composite structure.
引文
[1]聂建国,余志武.钢-混凝土组合梁在我国的应用及研究[J].土木工程学报,1999,32(2):3-8
[2]聂建国.钢-混凝上组合结构[M].北京:科学出版社,2005:60-76
[3]贺栓海.桥梁结构理论与计算方法[M].北京:人民交通出版社,2003:105-113
[4]聂建国,田春雨.简支组合梁板体系有效宽度分析[J].土木工程学报,2005,38(2):8-12
[5]聂建国,田春雨.钢-混凝土组合梁塑性阶段有效宽度分析[J].铁道科学与工程学报,2004,1(1):39-43
[6]C.Amodio C.Fedrigo.Experimental Study on Steel-concrete Composite Beams for Effective Width[J].Journal of Constructional Steel Research,February,2004:199-220
[7]Methee Chiewanichakorn,Amjad J Aref,Stuart S.Chen.Effective Flange Width Definition for Steel-Concrete Composite Bridge Girder[J].Journal of bridge engineering,2004,130:12
[8]Stuart S.Chen,Amjad J,Aref Methee Chiewanichakom.Proposed Effective Width Criteria for CompositeBridge Girders[J].Journal of bridge engineering,2007,12:3(325)
[9]马忠诚.钢-混凝土组合梁专题研究[M].哈尔滨:哈尔滨建筑大学科研资料,1995
[10]许兰兰,寇立亚.钢-混凝土组合粱混凝土翼板有效宽度对粱挠度的影响[J].建筑技术开发,2005,32(12):56-57
[11]李运生,王元清,石永久等.组合梁桥有效翼缘宽度国内外规范的比较分析[J].铁道科学与工程学报,2006,3(2):34-38
[12]王微微,孙振国,吕学涛.组合梁翼缘有效宽度研究进展[J].低温建筑技术,2005(5):85-86
[13]赵鸿铁.组合结构设计原理[M].北京:高等教育出版社,2005:67-93
[14]朱聘儒.钢-混凝土组合梁设计原理[M].北京:中国建筑工业出版社,1989:9-11
[15]项海帆.高等桥梁结构理论[M].北京:人民交通出版社,2002:215-219
[16]张士铎,邓小华,王文州.箱形薄壁梁剪力滞效应[M].北京:人民交通出版社,1997:1-3
[17]肖亚明,刘东营,何其洪.简支组合桁架的翼缘有效宽度研究[J].工程建设与档案,2005,19(4):305-308
[18]沈聚敏,王传志,江见鲸.钢筋混凝土有限元与板壳极限分析[M].北京:清华大学出版社,1993:85-135
[19]王勖成,邵敏.有限单元法基本原理和数值方法[M].第2版.北京:清华大学出版社,1997:84-116
[20]江见鲸,陆新,征,叶列平.混凝土结构有限元分析[M].北京:清华大学出版社,2005:
[21]GB 50010-2002.混凝土结构设计规范[S].北京,中华人民共和国建设部,2002
[22]张立明.Algor、Ansys在桥梁工程中的应用方法与实例[M].北京:人民交通出版社,2005:61-66
[23]李权.Ansys在土木工程中的应用[M].北京:人民邮电出版社,2005:187-192
[24]龚曙光,谢桂兰.Ansys操作命令与参数化编程[M].北京:机械工业出版社,2004:15-26
[25]JTJ 025-86.公路桥涵钢结构及木结构设计规范[S].北京,交通部公路规划设计院,1988
[26]LRFDSI-3.AASHTO LRFD Bridge Design Specifications[S].American Association of State Highway and Transportation Officials,2004
[27]BS 5400-5:1979.Steel,concrete and composite bridges(Part5)[S].London,British standard institution,1982
[28]Eurocode 4.Design of composite steel and concrete structures(Part1)[S].
[29]JTG D62-2004.公路钢筋混凝土及预应力混凝土桥涵设计规范[S].北京,中华人民共和国交通部,2004
[30]GB 50017-2003.钢结构设计规范[S].北京,中华人民共和国建设部,2003
[31]JTG D60-2004.公路桥涵设计通用规范[S].北京,中华人民共和国交通部,2004
[32]TB 10002.2-99.铁路桥梁钢结构设计规范[S].北京,中华人民共和国铁道部,2000
[33]GB/T 11263-2005.热轧H型钢和剖分T型钢[S].北京,中华人民共和国国家质量监督检验检疫总局,2005
[34] Adekola A O. Effective Width of Composite Beams of Steel and Concrete[J]. The Struct Eng, Sept, 1968: 285-289
[35] M.Chiewanichakorn, I-S.Ahn, A.J.Aref, S.S.Chen. The Development of Revised Effective Slab Width Criteria for Steel-Concrete Composite Bridges[J]. ASCE/SEI 2004 Structures Congress-Submission, no.208
[36] Mackey S. Effective Width of Composite Tee Beam Flange[J]. The Struct Engr, Sept,1961: 277-285
[2]聂建国.钢-混凝上组合结构[M].北京:科学出版社,2005:60-76
[3]贺栓海.桥梁结构理论与计算方法[M].北京:人民交通出版社,2003:105-113
[4]聂建国,田春雨.简支组合梁板体系有效宽度分析[J].土木工程学报,2005,38(2):8-12
[5]聂建国,田春雨.钢-混凝土组合梁塑性阶段有效宽度分析[J].铁道科学与工程学报,2004,1(1):39-43
[6]C.Amodio C.Fedrigo.Experimental Study on Steel-concrete Composite Beams for Effective Width[J].Journal of Constructional Steel Research,February,2004:199-220
[7]Methee Chiewanichakorn,Amjad J Aref,Stuart S.Chen.Effective Flange Width Definition for Steel-Concrete Composite Bridge Girder[J].Journal of bridge engineering,2004,130:12
[8]Stuart S.Chen,Amjad J,Aref Methee Chiewanichakom.Proposed Effective Width Criteria for CompositeBridge Girders[J].Journal of bridge engineering,2007,12:3(325)
[9]马忠诚.钢-混凝土组合梁专题研究[M].哈尔滨:哈尔滨建筑大学科研资料,1995
[10]许兰兰,寇立亚.钢-混凝土组合粱混凝土翼板有效宽度对粱挠度的影响[J].建筑技术开发,2005,32(12):56-57
[11]李运生,王元清,石永久等.组合梁桥有效翼缘宽度国内外规范的比较分析[J].铁道科学与工程学报,2006,3(2):34-38
[12]王微微,孙振国,吕学涛.组合梁翼缘有效宽度研究进展[J].低温建筑技术,2005(5):85-86
[13]赵鸿铁.组合结构设计原理[M].北京:高等教育出版社,2005:67-93
[14]朱聘儒.钢-混凝土组合梁设计原理[M].北京:中国建筑工业出版社,1989:9-11
[15]项海帆.高等桥梁结构理论[M].北京:人民交通出版社,2002:215-219
[16]张士铎,邓小华,王文州.箱形薄壁梁剪力滞效应[M].北京:人民交通出版社,1997:1-3
[17]肖亚明,刘东营,何其洪.简支组合桁架的翼缘有效宽度研究[J].工程建设与档案,2005,19(4):305-308
[18]沈聚敏,王传志,江见鲸.钢筋混凝土有限元与板壳极限分析[M].北京:清华大学出版社,1993:85-135
[19]王勖成,邵敏.有限单元法基本原理和数值方法[M].第2版.北京:清华大学出版社,1997:84-116
[20]江见鲸,陆新,征,叶列平.混凝土结构有限元分析[M].北京:清华大学出版社,2005:
[21]GB 50010-2002.混凝土结构设计规范[S].北京,中华人民共和国建设部,2002
[22]张立明.Algor、Ansys在桥梁工程中的应用方法与实例[M].北京:人民交通出版社,2005:61-66
[23]李权.Ansys在土木工程中的应用[M].北京:人民邮电出版社,2005:187-192
[24]龚曙光,谢桂兰.Ansys操作命令与参数化编程[M].北京:机械工业出版社,2004:15-26
[25]JTJ 025-86.公路桥涵钢结构及木结构设计规范[S].北京,交通部公路规划设计院,1988
[26]LRFDSI-3.AASHTO LRFD Bridge Design Specifications[S].American Association of State Highway and Transportation Officials,2004
[27]BS 5400-5:1979.Steel,concrete and composite bridges(Part5)[S].London,British standard institution,1982
[28]Eurocode 4.Design of composite steel and concrete structures(Part1)[S].
[29]JTG D62-2004.公路钢筋混凝土及预应力混凝土桥涵设计规范[S].北京,中华人民共和国交通部,2004
[30]GB 50017-2003.钢结构设计规范[S].北京,中华人民共和国建设部,2003
[31]JTG D60-2004.公路桥涵设计通用规范[S].北京,中华人民共和国交通部,2004
[32]TB 10002.2-99.铁路桥梁钢结构设计规范[S].北京,中华人民共和国铁道部,2000
[33]GB/T 11263-2005.热轧H型钢和剖分T型钢[S].北京,中华人民共和国国家质量监督检验检疫总局,2005
[34] Adekola A O. Effective Width of Composite Beams of Steel and Concrete[J]. The Struct Eng, Sept, 1968: 285-289
[35] M.Chiewanichakorn, I-S.Ahn, A.J.Aref, S.S.Chen. The Development of Revised Effective Slab Width Criteria for Steel-Concrete Composite Bridges[J]. ASCE/SEI 2004 Structures Congress-Submission, no.208
[36] Mackey S. Effective Width of Composite Tee Beam Flange[J]. The Struct Engr, Sept,1961: 277-285