侧向冲击荷载下钢筋混凝土墩柱的性能
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摘要
采用数值仿真技术建立了足尺钢筋混凝土墩柱精细有限元模型,分析了侧向冲击荷载下墩柱的动态响应和抗冲击性能,提出了一种基于截面损伤因子的损伤评估方法,讨论了不同碰撞参数对钢筋混凝土墩柱破坏模式和损伤机理的影响.结果表明:冲击荷载下钢筋混凝土墩柱的耗能主要分为接触区域局部耗能和构件整体耗能;当冲击体的初始动能恒定时,冲击质量和冲击速度的不同组合会导致钢筋混凝土墩柱损伤破坏机理的显著差异;基于截面损伤因子的损伤评估方法可以比较准确地描述墩柱的破坏状态.轴压力对墩柱抗撞能力的有利贡献比较有限,且墩柱随着轴力的增大更易发生剪切破坏;冲头刚度对碰撞力和墩柱动态响应的影响十分显著.
Anti-impact design is a very important aspect to ensure the safety of reinforced concrete( RC) bridges against extreme loads,such as explosions from terrorists attacks and accidental collisions of rockfalls and vehicles. The impact behavior of the pier columns,which is the most important vertical components in the bridge structures,have attracted much attention in recent years,and experimental studies on the impact behavior of scaled pier columns have been conducted by many researchers. It has been acknowledged that the size effect has a significant influence on the dynamic response of structural elements. Therefore,in this study,the performance of the prototype reinforced concrete pier columns under lateral impact loads was investigated. Using a numerical simulation technique,three-dimensional finite element models of a prototype pier column under impact loading were established and validated through comparisons with impact tests in the literature. A new damage assessment method based on the sectional damage factor was presented to determine the damage level of reinforced concrete pier columns. The effects of impact parameters such as impact mass,impact velocity,and impact stiffness on the failure mode and damage mechanism of reinforced concrete pier columns were also identified in detail. The simulation results show that the energy dissipation of reinforced concrete pier columns under impact loading can be divided into local energy dissipation in the contact area and overall energy dissipation in the whole component. When the initial kinetic energy of the impact body remains constant,different combinations of the impact mass and velocity can lead to a significant discrepancy in the damage mechanism of reinforced concrete pier columns. The proposed damage assessment method based on sectional damage factors can be utilized to accurately describe the failure state of the reinforced concrete pier columns. In addition,the contribution of the axial load to the impact capacity of reinforced concrete pier columns is limited,and the columns are more likely to suffer shear failure with the increasing axial force. The impact stiffness has a significant effect on the impact force and the dynamic response of reinforced concrete pier columns.
Anti-impact design is a very important aspect to ensure the safety of reinforced concrete( RC) bridges against extreme loads,such as explosions from terrorists attacks and accidental collisions of rockfalls and vehicles. The impact behavior of the pier columns,which is the most important vertical components in the bridge structures,have attracted much attention in recent years,and experimental studies on the impact behavior of scaled pier columns have been conducted by many researchers. It has been acknowledged that the size effect has a significant influence on the dynamic response of structural elements. Therefore,in this study,the performance of the prototype reinforced concrete pier columns under lateral impact loads was investigated. Using a numerical simulation technique,three-dimensional finite element models of a prototype pier column under impact loading were established and validated through comparisons with impact tests in the literature. A new damage assessment method based on the sectional damage factor was presented to determine the damage level of reinforced concrete pier columns. The effects of impact parameters such as impact mass,impact velocity,and impact stiffness on the failure mode and damage mechanism of reinforced concrete pier columns were also identified in detail. The simulation results show that the energy dissipation of reinforced concrete pier columns under impact loading can be divided into local energy dissipation in the contact area and overall energy dissipation in the whole component. When the initial kinetic energy of the impact body remains constant,different combinations of the impact mass and velocity can lead to a significant discrepancy in the damage mechanism of reinforced concrete pier columns. The proposed damage assessment method based on sectional damage factors can be utilized to accurately describe the failure state of the reinforced concrete pier columns. In addition,the contribution of the axial load to the impact capacity of reinforced concrete pier columns is limited,and the columns are more likely to suffer shear failure with the increasing axial force. The impact stiffness has a significant effect on the impact force and the dynamic response of reinforced concrete pier columns.
引文
[1] Tian L,Zhu C. Damage evaluation and protection technique of RC columns under impulsive load. Eng Mech,2013,30(9):144(田力,朱聪.碰撞冲击荷载作用下钢筋混凝土柱的损伤评估及防护技术.工程力学,2013,30(9):144)
[2] Cheng X W,Li Y,Lu X Z,et al. Numerical investigation on dynamic response of reinforced concrete columns subjected to impact loading. Eng Mech,2015,32(2):53(程小卫,李易,陆新征,等.撞击荷载下钢筋混凝土柱动力响应的数值研究.工程力学,2015,32(2):53)
[3] Loedolff M J. The Behaviour of Reinforced Concrete Cantilever Columns under Lateral Impact Load[Dissertation]. Stellenbosch:Stellenbosch University,1989
[4] Liu F,Luo Q Z,Yan B,et al. Numerical study on the failure mode of RC column subjected to lateral impact. J Vib Shock,2017,36(16):122(刘飞,罗旗帜,严波,等. RC柱侧向冲击破坏模式的数值模拟研究.振动与冲击,2017,36(16):122)
[5] Demartino C,Wu J G,Xiao Y. Response of shear-deficient reinforced circular RC columns under lateral impact loading. Int J Impact Eng,2017,109:196
[6] Cai J,Ye J B,Chen Q J,et al. Dynamic behaviour of axiallyloaded RC columns under horizontal impact loading. Eng Struct,2018,168:684
[7] Zhou X Y,Ma R J,Chen A R. Anti-shear reliability analysis for a reinforced concrete column subjected to rockfall impact. J Vib Shock,2017,36(7):262(周晓宇,马如进,陈艾荣.钢筋混凝土柱式墩落石冲击抗剪性能可靠性分析.振动与冲击,2017,36(7):262)
[8] Editorial Department of China Journal of Highway and Transport.Review on China's bridge engineering research:2014. China J High-way Transp,2014,27(5):1(《中国公路学报》编辑部.中国桥梁工程学术研究综述2014.中国公路学报,2014,27(5):1)
[9] Kishi N,Bhatti A Q. An equivalent fracture energy concept for nonlinear dynamic response analysis of prototype RC girders subjected to falling-weight impact loading. Int J Impact Eng,2010,37(1):103
[10] Murray Y D. Users Manual for LS--DYNA Concrete Material Model159. Report No. FHWA-HRT-05-062,2007
[11] Jones N. Structural Impact. 2nd Ed. New York:Cambridge University Press,2012
[12] Hallquist J O. LS-DYNA Keyword User's Manual Version 971.Livermore:Livermore Software Technology Corporation,2007
[13] Sharma H,Gardoni P,Hurlebaus S. Probabilistic demand model and performance-based fragility estimates for RC column subject to vehicle collision. Eng Struct,2014,74:86
[14] Thilakarathna H M I. Vulnerability Assessment of Reinforced Concrete Columns Subjected to Vehicular Impacts. Queensland:Queensland University of Technology,2010
[15] Ministry of Housing and Urban-Rural Development,People's Republic of China. GB50010—2010 Code for Design of Concrete Structures. Beijing:China Architecture&Building Press,2010(中华人民共和国住房和城乡建设部. GB50010—2010混凝土结构设计规范.北京:中国建筑工业出版社,2010)
[2] Cheng X W,Li Y,Lu X Z,et al. Numerical investigation on dynamic response of reinforced concrete columns subjected to impact loading. Eng Mech,2015,32(2):53(程小卫,李易,陆新征,等.撞击荷载下钢筋混凝土柱动力响应的数值研究.工程力学,2015,32(2):53)
[3] Loedolff M J. The Behaviour of Reinforced Concrete Cantilever Columns under Lateral Impact Load[Dissertation]. Stellenbosch:Stellenbosch University,1989
[4] Liu F,Luo Q Z,Yan B,et al. Numerical study on the failure mode of RC column subjected to lateral impact. J Vib Shock,2017,36(16):122(刘飞,罗旗帜,严波,等. RC柱侧向冲击破坏模式的数值模拟研究.振动与冲击,2017,36(16):122)
[5] Demartino C,Wu J G,Xiao Y. Response of shear-deficient reinforced circular RC columns under lateral impact loading. Int J Impact Eng,2017,109:196
[6] Cai J,Ye J B,Chen Q J,et al. Dynamic behaviour of axiallyloaded RC columns under horizontal impact loading. Eng Struct,2018,168:684
[7] Zhou X Y,Ma R J,Chen A R. Anti-shear reliability analysis for a reinforced concrete column subjected to rockfall impact. J Vib Shock,2017,36(7):262(周晓宇,马如进,陈艾荣.钢筋混凝土柱式墩落石冲击抗剪性能可靠性分析.振动与冲击,2017,36(7):262)
[8] Editorial Department of China Journal of Highway and Transport.Review on China's bridge engineering research:2014. China J High-way Transp,2014,27(5):1(《中国公路学报》编辑部.中国桥梁工程学术研究综述2014.中国公路学报,2014,27(5):1)
[9] Kishi N,Bhatti A Q. An equivalent fracture energy concept for nonlinear dynamic response analysis of prototype RC girders subjected to falling-weight impact loading. Int J Impact Eng,2010,37(1):103
[10] Murray Y D. Users Manual for LS--DYNA Concrete Material Model159. Report No. FHWA-HRT-05-062,2007
[11] Jones N. Structural Impact. 2nd Ed. New York:Cambridge University Press,2012
[12] Hallquist J O. LS-DYNA Keyword User's Manual Version 971.Livermore:Livermore Software Technology Corporation,2007
[13] Sharma H,Gardoni P,Hurlebaus S. Probabilistic demand model and performance-based fragility estimates for RC column subject to vehicle collision. Eng Struct,2014,74:86
[14] Thilakarathna H M I. Vulnerability Assessment of Reinforced Concrete Columns Subjected to Vehicular Impacts. Queensland:Queensland University of Technology,2010
[15] Ministry of Housing and Urban-Rural Development,People's Republic of China. GB50010—2010 Code for Design of Concrete Structures. Beijing:China Architecture&Building Press,2010(中华人民共和国住房和城乡建设部. GB50010—2010混凝土结构设计规范.北京:中国建筑工业出版社,2010)