钢筋混凝土箱梁近场爆炸响应的试验与数值模拟  

Test and numerical study on the near-field explosion response of reinforced concrete box girder

作　　者：周广盼[1] 林志成 王明洋[2,3] 范进 张于晔[1] ZHOU Guangpan;LIN Zhicheng;WANG Mingyang;FAN Jin;ZHANG Yuye(School of Science,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China;School of Mechanical Engineering,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China;State Key Laboratory of Explosion and Impact and Disaster Prevention and Mitigation,Army Engineering University of PLA,Nanjing 210007,Jiangsu,China)

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]南京理工大学机械工程学院,江苏南京210094 [3]陆军工程大学爆炸冲击防灾减灾国家重点实验室,江苏南京210007

出　　处：《爆炸与冲击》2023年第7期23-37,共15页Explosion and Shock Waves

基　　金：江苏省自然科学基金(BK20200494,BK20211196);国家自然科学基金(52278188);中国博士后科学基金(2021M701725);江苏省博士后科研资助计划(2021K522C);中央高校基本科研业务费专项资金(30919011246)。

摘　　要：为了研究近场爆炸作用下单箱三室混凝土箱梁的动力响应和破坏特征,开展了缩比试件爆炸试验和数值模拟。以原型桥梁主梁截面按1∶3缩比设计和制作了箱梁试件,测量了3 kg TNT药柱爆炸作用下试件的反射超压、钢筋应变、竖向位移及破洞形态;采用LS-DYNA软件进行了箱梁爆炸响应模拟,结合试验数据验证了数值模拟方法的可靠性;分析了TNT当量、起爆位置、混凝土强度、配筋率对箱梁抗爆性能的影响。结果表明:3 kg TNT药柱于箱梁中间箱室中心正上方0.4 m处起爆时,在中间箱室顶板中心形成一个椭圆形的贯穿破口,破口沿横、纵桥向长度分别为41.50、45.50 cm;中间箱室顶板底面的混凝土发生大面积剥落,呈现喇叭状冲切破坏特征;多室箱梁的超宽截面形式使得其爆炸响应沿横桥向分布不均匀;箱梁底板竖向位移峰值和钢筋应变峰值随药量的增大而增大,采用最小二乘法得到了对应的拟合曲线表达式;不同起爆位置下,中间箱室底板中心的竖向位移均大于两侧箱室中心的。In order to study the dynamic response and failure characteristics of the concrete girder with single box and three chambers under near-field explosion,the explosion test and numerical simulation of a scaled specimen were carried out.The girder specimen was designed and manufactured by the scale of 1∶3 according to the prototype bridge girder.The bottom of the specimen was supported by six brick supports.The TNT grain was located at 0.4 m above the top plate center of the middle chamber with an equivalent of 3 kg and a proportional distance of 0.77 m/kg1/3.The reflected overpressure,reinforcement strain,vertical displacement and acceleration of bottom plate and the shape of breach were measured and analyzed.The effectiveness of the explosion load in the test was verified by comparing the measured reflection overpressure with the calculated value by the CONWEP empirical formula.The LS-DYNA software was used to simulate the explosion response of the box girder.The SOLIDWORKS software and HYPERMESH software were used to establish the finite element model of the specimen.The Solid 164 element was used to simulate the concrete,and Beam 188 element was used to simulate the steel rebar.The LOAD BLAST ENHANCED(LBE)method was used to apply explosive loads.The*MAT_CONCRETE_DAMAGE_REL3 material model and*MAT_PLASTIC_KINEMATIC model were used to simulate the concrete and rebar,respectively,to consider the effects caused by high strain and large deformation.The keyword*MAT_ADD_EROSION was used to define the failure of concrete.The reliability of numerical simulation method was verified with the test data.Finally,the effects of TNT equivalent,detonation location,concrete strength,and reinforcement ratio on the explosion resistance of the box girder were analyzed.The results show that when a TNT grain of 3 kg is detonated at 0.4 m above the center of the middle chamber of the box girder,an elliptical penetration breach is formed in the center of top plate of the middle chamber,with the length values along the transverse and l

关 键 词：桥梁工程 钢筋混凝土箱梁 近场爆炸 爆炸响应 

分 类 号：O383[理学—流体力学] U447[理学—力学]