鉴于现行结构抗爆设计规范中采用简化的线性衰减爆炸荷载模式,其等效作用时长小于爆炸荷载真实作用时长。本文以等冲量、等超压峰值为条件,采用级数型爆炸荷载模式,建立真实作用时长与等效作用时长关系,求解结构弹塑性振动微分方程,推导出一三次项、二三次项两种级数型爆炸荷载等效静载动力系数。结合现行规范中简化的动力系数对比,通过典型工况计算算例表明:整体上,级数型爆炸荷载比等冲量线性爆炸荷载求出的动力系数数值低;延性比β<2.5且结构荷载参数θi<1.2时,级数型爆炸荷载与等冲量线性爆炸荷载动力系数差异小于2%,可直接采用规范简化公式;β<2.5且θi≥1.2时,一三次项级数型爆炸荷载动力系数整体偏小;β≥2.5且θi<1.2时,一三次项与二三次项级数型爆炸荷载动力系数差异可忽略,两者与规范简化公式差异在8%以上;β≥2.5且θi≥1.2时,动力系数与衰减曲线波形系数a及级数荷载类型相关性较高。
Abstract
In view of the simplified linear attenuation blast loading model used in current structural anti-explosion design codes, the equivalent duration is less than the true duration of overpressure blast loading. Under the condition of equal impulse and equal overpressure peak, the series curve attenuation function is adopted as conventional weapon chemical blast loading. The relationship between true duration and equivalent duration is established. Both one-three and two-three term dynamic coefficients of series curve attenuation blast loading is derived from structural elastic-plastic vibration equation. Based on the simplified dynamic coefficient in current code, some typical calculation situations show that the value from this paper is lower than the vale from the current code. When the ductility ratio β<2.5 and structural load is<1.2, the calculation result difference from this paper and the current code is 2% so that the formula from current code can be directly used. When β<2.5 and mi≥1.2, the dynamic coefficients of one-three term series blast loading are relatively small. When β≥2.5 and in<1.2, the difference between one-third term series and second-third series is negligible, and the maximum difference between the series formula and simplified formula is more than 8%. When β≥2.5 and θi≥1.2, the dynamic coefficient has a high correlation with curve shape factor a and series type of blast loading.
关键词
常规武器 /
爆炸荷载 /
动力系数 /
延性比 /
作用时长
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Key words
conventional weapon /
blast loading /
dynamic coefficient /
ductility ratio /
loading duration
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参考文献
[1] TM5-1300. Structures to Resist the Effects of Accidental Explosions[S]. Washington DC,USA: USA Army Corps of Engineering,1990.
[2] TM5-855-l. Fundamentals of Protective Design for Conventional Weapons[S]. Washington DC, USA:US Army Corps of Engineers,1986.
[3] UFC 3-340-02. Structures to Resist the Effects of Accidental Explosions[S]. Washington DC,USA: USA Army Corps of Engineering,2008.
[4] CSA/S 850-12 Design and assessment of buildings subjects to blast loads[S]. Ontario,Canada: Canadian Standards Association,2012.
[5] 人民防空地下室设计规范: GB 50038-2005[S]. 北京:中国建筑工业出版社,2005.
Code for design of civil air defence basement: GB 50038-2005[S]. Beijing: China Architecture & Building Press,2005.
[6] 建筑结构荷载规范:GB 50009-2012[S]. 北京: 中国建筑工业出版社, 2012.
Load code for the design of building structures: GB 50009-2012[S]. Beijing: China Architecture & Building Press,2012.
[7] BIGGS J M. Introduction to structure dynamics [M]. New York: McGraw-Hill Book Company, 1964: 315-327.
[8] 杨科之, 王年桥. 化爆条件下地面结构等效静载计算方法 [J].防护工程, 2001, 23(2): 1-7.
YANG Kezhi, WANG Nianqiao. Equivalent static load calculation method for ground structures under chemical explosion [J].Protective Engineering, 2001, 23(2): 1-7.
[9] 方秦,陈力,张亚栋,等.爆炸荷载作用下钢筋混凝土结构的动态响应与破坏模式的数值分析[J].工程力学,2007, 24(S2):135-144.
FANG Qin, CHEN Li, ZHANG Yadong, et al. Numerical investigation for dynamic response and failure modes of RC structures due to blast loading[J]. Engineering Mechanics, 2007, 24(S2):135-144.
[10] 柳锦春,荣超,陈力.爆炸作用下钢筋混凝土-钢板组合梁动力响应分析[J].建筑结构学报,2015,36(S1): 349-354.
LIU Jinchun, RONG Chao, CHEN Li. Dynamic responses analysis of steel-backed reinforced concrete composite beams subjected to blast loading[J]. Journal of Building Structures, 2015,36(S1): 349-354.
[11] NAGATA M, BEPPU M, ICHINO H. Method for evaluating the displacement response of RC beams subjected to close-in explosion using modified SDOF model[J]. Engineering Structures, 2018,157(04):105- 118.
[12] 师燕超,张浩,李忠献.钢筋混凝土梁式构件抗爆分析的改进等效单自由度方法[J].建筑结构学报, 2019, 40(10):8-16.(SHI Yanchao, ZHANG Hao, LI Zhongxian. Improved equivalent single degree of freedom method for blast analysis of RC beams[J]. Journal of Building Structures,2019,40(10):8-16.
[13] 李忠献,路建辉,师燕超,等.不确定爆炸荷载作用下钢梁的可靠度分析[J].工程力学,2014,31(04):112-118. LI Zhong xian, LU Jianhui, SHI Yanchao, et al. Reliability analysis of steel beam under uncertain blast loads[J]. Engineering Mechanics, 2014, 31(04):112- 118.
[14] STOCHINO F. RC beams under blast load: reliability and sensitivity analysis[J]. Engineering Failure Analysis, 2016,66(03):544-576.
[15] 耿少波, 葛培杰, 刘亚玲,等. 化学爆炸等效单自由度结构体系抗力动力系数分析[J]. 振动与冲击, 2019, 38(6):166-171.
GENG Shaobo, GE Peijie, LIU Yaling,et al. Dynamical coefficient of resistance of an equivalent SDOF structural system under chemical explosion load [J]. Journal of Vibration and Shock, 2019,38(6):106-111.
[16] 耿少波,葛培杰,李洪,等.爆炸荷载结构等效静载动力系数研究[J].兵工学报,2019, 40(10): 2088-2095. GENG Shaobo, GE Peijie, LI Hong, et al. Equivalent static load dynamic coefficient for blast load[J]. Acta Armamentarii, 2019, 40(10): 2088-2095.
[17] GANTES J, PNEVMATIKOS G. Elasticplastic response spectra for exponential blast loading [J]. International Journal of Impact Engineering, 2004, 30(3): 323-343.
[18] YI F, LI C, QIN F, et al Blast resistance of Externally Prestressed RC Beam: A Theoretical Approach. Engineering Structures. 2019,179(07): 211-224.
[19] LI Y, AOUDE H. Blast response of beams built with high strength concrete and high strength ASTM A1035 bars[J]. International Journal of Impact Engineering, 2019,130(08):41-67.
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