车辆荷载作用下损伤开裂简支空心板的断裂力学特征
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摘要
准确掌握不同损伤条件下桥梁结构的动态特性及其变化规律是动态检测法快速检测与准确评价桥梁安全性的前提,而目前对车辆荷载作用下不同损伤开裂混凝土梁桥断裂力学特征的研究成果还很不充分。基于断裂力学理论,以钢筋混凝土简支空心板为研究对象,采用有限元数值模拟方法,对车辆荷载作用下损伤开裂混凝土简支空心板的断裂力学特征进行了研究。基于裂缝穿过空心板底部受力筋的层数确定开裂深度,通过对车辆荷载作用下8 m标准跨径混凝土空心板中部不同开裂深度的计算分析,得到了不同工况下空心板横截面上裂缝附近的J积分值均呈现由两侧向中间先增加后减小的规律,即裂缝附近J积分值的大小与空心板横截面的净高有关,净高越小,J积分值越大,净高越大,J积分值越小,且同一加载方式下,裂缝附近J积分值的大小与空心板横截面的净高有关;在相同加载方式下,裂缝附近的J积分值和裂缝开度随着裂缝深度的增加而呈几何加速度增加,各裂缝尖端的Von Mises应力则近似呈现线性增大;在相同裂缝深度时,加载荷载越大,裂缝附近的J积分值也越大,且J积分值在反映载荷变化时具有较高的敏感性。
As the precondition for rapid detection and accurate evaluation of bridge safety by using the dynamic test method,the dynamic characteristics and its change rules of bridge structure under different damaged conditions must be mastered accurately. However, the researches for fracture mechanical characteristics of concrete girder bridge with different cracks under vehicle loads are inadequate. Taking reinforced concrete simply supported hollow slab as the research object,based on the fracture mechanics theory,the fracture mechanical characteristics of concrete simply supported hollow slab with different crack depths under vehicle load are analyzed by applying the finite element numerical simulation method. The crack depth is determined based on the number of layers of reinforced bars in the bottom of the hollow plate.Through the calculation and analysis of different cracking depths in the middle part of a 8 m standard span concrete hollow slab under vehicle load,it is obtained that( 1) The J integral value on hollow slab cross-section near the cracks under different working conditions firstly increased and then decreased from sides to center along the crack. Namely,the size of the J integral value near the crack associated with the clear height of hollow slab cross-section. The smaller the clear height,the greater the J integral value,and vice versa,and the J integral value associated with the clear height of hollow slab cross-section under the same loading mode.( 2) With the increase of crack depth under the same loading mode,the J integral value and crack opening increased geometrically,while the crack tip Von Mises stress increased approximate linearly.( 3) In the same crack depth,the J integral value near the cracks increased with the increase of vehicle load,and the J integral value is highly sensitive with the change of load.
As the precondition for rapid detection and accurate evaluation of bridge safety by using the dynamic test method,the dynamic characteristics and its change rules of bridge structure under different damaged conditions must be mastered accurately. However, the researches for fracture mechanical characteristics of concrete girder bridge with different cracks under vehicle loads are inadequate. Taking reinforced concrete simply supported hollow slab as the research object,based on the fracture mechanics theory,the fracture mechanical characteristics of concrete simply supported hollow slab with different crack depths under vehicle load are analyzed by applying the finite element numerical simulation method. The crack depth is determined based on the number of layers of reinforced bars in the bottom of the hollow plate.Through the calculation and analysis of different cracking depths in the middle part of a 8 m standard span concrete hollow slab under vehicle load,it is obtained that( 1) The J integral value on hollow slab cross-section near the cracks under different working conditions firstly increased and then decreased from sides to center along the crack. Namely,the size of the J integral value near the crack associated with the clear height of hollow slab cross-section. The smaller the clear height,the greater the J integral value,and vice versa,and the J integral value associated with the clear height of hollow slab cross-section under the same loading mode.( 2) With the increase of crack depth under the same loading mode,the J integral value and crack opening increased geometrically,while the crack tip Von Mises stress increased approximate linearly.( 3) In the same crack depth,the J integral value near the cracks increased with the increase of vehicle load,and the J integral value is highly sensitive with the change of load.
引文
[1]高丹盈,张明.疲劳荷载下钢筋钢纤维高强混凝土梁受压边缘累积残余应变计算方法[J].中国公路学报,2016,29(3):48-54.GAO Dan-ying,ZHANG Ming.Calculation Method on Cumulative Residual Compressive Strain at Compressive Edge of Steel Fiber Reinforced High-strength Concrete Beams under Fatigue Load[J].China Journal of Highway and Transport,2016,29(3):48-54.
[2]张耀庭,杜晓菊,杨力.RC框架结构基于构件损伤的抗震性能评估研究[J].湖南大学学报:自然科学版,2016,43(5):9-21.ZHANG Yao-ting,DU Xiao-ju,YANG Li.Research on Seismic Performance Assessment Based on Component Damage for RC Frame Structure[J].Journal of Hunan University:Natural Science Edition,2016,43(5):9-21.
[3]毛江鸿,金伟良,李志远,等.氯盐侵蚀钢筋混凝土桥梁耐久性提升及寿命预测[J].中国公路学报,2016,29(1):61-66.MAO Jiang-hong,JIN Wei-liang,LI Zhi-yuan,et al.Durability Improvement and Service Life Prediction of Reinforced Concrete Bridge under Chloride Attack[J].China Journal of Highway and Transport,2016,29(1):61-66.
[4]郭孟环.基于振动的桥梁模态识别与损伤检测[D].北京:北京交通大学,2013.GUO Meng-huan.Vibration Based Bridge Modal Identification and Damage Detection[D].Beijing:Beijing Jiaotong University,2013.
[5]余加勇.基于GNSS和RTS技术的桥梁结构动态变形监测研究[D].长沙:湖南大学,2014.YU Jia-yong.GNSS and RTS Technologies Based Structural Dynamic Deformation Monitoring of Bridges[D].Changsha:Hunan University,2014.
[6]李焕兰.简支梁桥损伤状态下车桥耦合动态响应分析[D].大连:大连海事大学,2014.LI Huan-lan.Dynamic Response Analysis of Vehiclebridge Coupling under Damaged State of Simply Supported Girder Bridge[D].Dalian:Dalian Maritime University,2014.
[7]LAW S S,ZHU X Q.Dynamic Behavior of Damaged Concrete Bridge Structures under Moving Vehicular Loads[J].Engineering Structures,2004,26(9):1279-1293.
[8]YANG J,CHEN Y,XIANG Y,et al.Free and Forced Vibration of Cracked in Homogeneous Beams under an Axial Force and a Moving Load[J].Journal of Sound and Vibration,2008,312(1/2):166-181.
[9]LU Z R,LIU J K,HUANG M,et al.Identification of Local Damages in Coupled Beam Systems from Measured Dynamic Responses[J].Journal of Sound and Vibration,2009,326(1/2):177-189.
[10]张艳奇,吕克金,张林洪.钢筋混凝土梁的断裂力学分析[J].四川水力发电,2011,30(1):76-88.ZHANG Yan-qi,LKe-jin,ZHANG Lin-hong.Fracture Mechanics Analysis of Reinforced Concrete Beams[J].Sichuan Water Power,2011,30(1):76-88.
[11]蒋梅玲,金贤玉,田野,等.基于断裂力学和损伤理论的混凝土开裂模型[J].浙江大学学报:工学版,2011,45(5):948-953.JIANG Mei-ling,JIN Xian-yu,TIAN Ye,et al.New Concrete Cracking Model Established Based on Fracture Mechanics and Damage Theory[J].Journal of Zhejiang University:Engineering Science Edition,2011,45(5):948-953.
[12]赵亚敏,唐习龙.基于ANSYS钢筋混凝土梁开裂有限元模拟研究[J].西部探矿工程,2007,19(12):231-233.ZHAO Ya-min,TANG Xi-long.Finite Element Simulation on Crack of Reinforced Concrete Beam Based on ANSYS[J].West-China Exploration Engineering,2007,19(12):231-233.
[13]GB 50010-2010,混凝土结构设计规范[S].GB 50010-2010,Code for Design of Concrete Structures[S].
[14]PIYASENA R,LOO Y C,FRAGOMENI S.Factors Influencing Spacing and Width of cracks in Reinforced Concrete:New Prediction Formulae[J].Advances in Structural Engineering,2009,7(1):49-60.
[15]丁嵬.钢筋混凝土结构裂缝宽度计算方法研究[D].天津:天津大学,2007.DING Wei.Study on Crack Width Calculation Methods of Reinforced Concrete Structure[D].Tianjin:Tianjin University,2007.
[16]BASE G D.Crack Control in Reinforced Concrete:Present Position[C]//Symposium on Serviceability of Concrete.Melbourne:[s.n.],1975:387-399.
[17]RICE J R.A Path Independent Integral and the Approximate Analysis of Strain Concentration by Notches and Cracks[J].Journal of Applied Mechanics,1968,35(2):379-386.
[18]许伦辉,罗强,吴建伟,等.基于最小安全距离的车辆跟驰模型研究[J].公路交通科技,2010,27(10):95-100.XU Lun-hui,LUO Qiang,WU Jian-wei,et al.Study of Car-following Model Based on Minimum Safety Distance[J].Journal of Highway and Transportation Research and Development,2010,27(10):95-100.
[2]张耀庭,杜晓菊,杨力.RC框架结构基于构件损伤的抗震性能评估研究[J].湖南大学学报:自然科学版,2016,43(5):9-21.ZHANG Yao-ting,DU Xiao-ju,YANG Li.Research on Seismic Performance Assessment Based on Component Damage for RC Frame Structure[J].Journal of Hunan University:Natural Science Edition,2016,43(5):9-21.
[3]毛江鸿,金伟良,李志远,等.氯盐侵蚀钢筋混凝土桥梁耐久性提升及寿命预测[J].中国公路学报,2016,29(1):61-66.MAO Jiang-hong,JIN Wei-liang,LI Zhi-yuan,et al.Durability Improvement and Service Life Prediction of Reinforced Concrete Bridge under Chloride Attack[J].China Journal of Highway and Transport,2016,29(1):61-66.
[4]郭孟环.基于振动的桥梁模态识别与损伤检测[D].北京:北京交通大学,2013.GUO Meng-huan.Vibration Based Bridge Modal Identification and Damage Detection[D].Beijing:Beijing Jiaotong University,2013.
[5]余加勇.基于GNSS和RTS技术的桥梁结构动态变形监测研究[D].长沙:湖南大学,2014.YU Jia-yong.GNSS and RTS Technologies Based Structural Dynamic Deformation Monitoring of Bridges[D].Changsha:Hunan University,2014.
[6]李焕兰.简支梁桥损伤状态下车桥耦合动态响应分析[D].大连:大连海事大学,2014.LI Huan-lan.Dynamic Response Analysis of Vehiclebridge Coupling under Damaged State of Simply Supported Girder Bridge[D].Dalian:Dalian Maritime University,2014.
[7]LAW S S,ZHU X Q.Dynamic Behavior of Damaged Concrete Bridge Structures under Moving Vehicular Loads[J].Engineering Structures,2004,26(9):1279-1293.
[8]YANG J,CHEN Y,XIANG Y,et al.Free and Forced Vibration of Cracked in Homogeneous Beams under an Axial Force and a Moving Load[J].Journal of Sound and Vibration,2008,312(1/2):166-181.
[9]LU Z R,LIU J K,HUANG M,et al.Identification of Local Damages in Coupled Beam Systems from Measured Dynamic Responses[J].Journal of Sound and Vibration,2009,326(1/2):177-189.
[10]张艳奇,吕克金,张林洪.钢筋混凝土梁的断裂力学分析[J].四川水力发电,2011,30(1):76-88.ZHANG Yan-qi,LKe-jin,ZHANG Lin-hong.Fracture Mechanics Analysis of Reinforced Concrete Beams[J].Sichuan Water Power,2011,30(1):76-88.
[11]蒋梅玲,金贤玉,田野,等.基于断裂力学和损伤理论的混凝土开裂模型[J].浙江大学学报:工学版,2011,45(5):948-953.JIANG Mei-ling,JIN Xian-yu,TIAN Ye,et al.New Concrete Cracking Model Established Based on Fracture Mechanics and Damage Theory[J].Journal of Zhejiang University:Engineering Science Edition,2011,45(5):948-953.
[12]赵亚敏,唐习龙.基于ANSYS钢筋混凝土梁开裂有限元模拟研究[J].西部探矿工程,2007,19(12):231-233.ZHAO Ya-min,TANG Xi-long.Finite Element Simulation on Crack of Reinforced Concrete Beam Based on ANSYS[J].West-China Exploration Engineering,2007,19(12):231-233.
[13]GB 50010-2010,混凝土结构设计规范[S].GB 50010-2010,Code for Design of Concrete Structures[S].
[14]PIYASENA R,LOO Y C,FRAGOMENI S.Factors Influencing Spacing and Width of cracks in Reinforced Concrete:New Prediction Formulae[J].Advances in Structural Engineering,2009,7(1):49-60.
[15]丁嵬.钢筋混凝土结构裂缝宽度计算方法研究[D].天津:天津大学,2007.DING Wei.Study on Crack Width Calculation Methods of Reinforced Concrete Structure[D].Tianjin:Tianjin University,2007.
[16]BASE G D.Crack Control in Reinforced Concrete:Present Position[C]//Symposium on Serviceability of Concrete.Melbourne:[s.n.],1975:387-399.
[17]RICE J R.A Path Independent Integral and the Approximate Analysis of Strain Concentration by Notches and Cracks[J].Journal of Applied Mechanics,1968,35(2):379-386.
[18]许伦辉,罗强,吴建伟,等.基于最小安全距离的车辆跟驰模型研究[J].公路交通科技,2010,27(10):95-100.XU Lun-hui,LUO Qiang,WU Jian-wei,et al.Study of Car-following Model Based on Minimum Safety Distance[J].Journal of Highway and Transportation Research and Development,2010,27(10):95-100.