Numerical study on dynamic response and spall damage of filter concrete under impact load
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摘要: 借鉴局域共振材料的工作机制,通过在混凝土基体中嵌入滤波单元,设计出具有应力波衰减特性的滤波混凝土。通过将滤波混凝土结构简化为质量弹簧力学系统来分析滤波混凝土对应力波的衰减机制。采用数值模拟方法,对比研究了冲击荷载作用下普通混凝土模型和滤波混凝土模型中应力波的传播特性和层裂破坏模式。通过参数分析,研究了滤波单元的材料和几何属性对其储能效果的影响。研究结果表明:滤波单元有效降低了混凝土基体中应力波的传播速度和应力峰值;滤波单元的储能机制有效降低了混凝土基体中的能量;金属球的质量越大,滤波单元的储能效果越好,但弹性层的弹性模量和厚度需要通过适当分析进行设计以实现滤波单元的储能最大化;滤波混凝土基体的局部损伤耗散了荷载中的大量能量,有效降低了结构自由面附近的破坏程度。Abstract: Based on the working mechanism of local resonance materials, a filter concrete with stress wave attenuation characteristics is designed by embedding metal balls wrapped with elastic layer (filter units) in the concrete matrix. First, the stress wave attenuation mechanism of filter concrete is analyzed by simplifying the filter concrete structure into a mass-spring mechanical system. Then, the propagation velocity and peak stress of stress wave in normal concrete model and filter concrete model under impact load are compared by using numerical simulation approach. Through parameter analysis, the influence of the density of metal ball, elastic modulus and thickness of elastic layer on the energy storage of filter units are studied. Finally, the spalling damage patterns of normal concrete model and filter concrete model under impact load are compared. The results show that the filter units can effectively reduce the stress wave propagation velocity and magnitude of peak stress in the concrete matrix. The vibration of the metal balls and the deformation of the elastic layer form a good energy storage mechanism for filter units and effectively reduce the energy exerted by the impact load on the concrete matrix. The larger the mass of the metal balls, the better the energy storage effect of the filter units, while the elastic modulus and thickness of the elastic layer need to be designed through a proper analysis to maximize the energy storage of the filter units. The concrete matrix around the elastic layer has obvious stress concentration and local damage may occur, but the local damage of the filter concrete matrix dissipates a large amount of energy produced by the load, effectively reducing the degree of destruction near the free surface of the structure. Combined with the attenuation effect of the filter units on the stress wave, the filter concrete has achieved good impact resistance.
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Key words:
- filter concrete /
- local resonance /
- spalling damage /
- stress wave /
- energy storage mechanism
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表 1 混凝土的材料参数
Table 1. Material parameters of concrete
ρ/(kg·m−3) σc/MPa σt/MPa E/GPa μ a0y/MPa a1y 2 440 34 2.7 30 0.156 8.93 0.625 a2y/MPa−1 a0/MPa a1 a2/MPa−1 a1f a2f/MPa−1 6.437×10−3 11.82 0.446 2.02×10−3 0.442 2.957×10−3 表 2 滤波单元的材料参数
Table 2. Material parameters of a filter unit
材料 ρ/(kg·m−3) E/GPa μ 铅 11400 160 0.44 天然橡胶 900 0.047 0.42 表 3 滤波混凝土模型的几何参数
Table 3. Geometric parameters of the filter concrete model
L/mm D/mm l/mm r/mm T/mm 500 74 75 22 2 -
[1] WU J, ZHOU Y, ZHANG R, et al. Numerical simulation of reinforced concrete slab subjected to blast loading and the structural damage assessment [J]. Engineering Failure Analysis, 2020, 118: 104926. DOI: 10.1016/j.engfailanal.2020.104926. [2] 汪维. 钢筋混凝土构件在爆炸载荷作用下的毁伤效应及评估方法研究 [D]. 长沙: 国防科学技术大学, 2012.WANG W. Study on damage effects and assessments method of reinforced concrete structural members under blast loading [D]. Changsha, Hunan, China: National University of Defense Technology, 2012. [3] CHEN G, HAO Y F, HAO H. 3D meso-scale modelling of concrete material in spall tests [J]. Materials and Structures, 2015, 48(6): 1887–1899. DOI: 10.1617/s11527-014-0281-z. [4] 郭弦. 冲击作用下混凝土中应力波传播规律研究 [D]. 长沙: 国防科学技术大学, 2010.GUO X. Stress wave propagation in concrete structure under impact loading [D]. Changsha, Hunan, China: National University of Defense Technology, 2010. [5] 巫绪涛, 廖礼. 脆性材料中应力波衰减规律与层裂实验设计的数值模拟 [J]. 爆炸与冲击, 2017, 37(4): 705–711. DOI: 10.11883/1001-1455(2017)04-0705-07.WU X T, LIAO L. Numerical simulation of stress wave attenuation in brittle material and spalling experiment design [J]. Explosion and Shock Waves, 2017, 37(4): 705–711. DOI: 10.11883/1001-1455(2017)04-0705-07. [6] 俞鑫炉, 付应乾, 董新龙, 等. 混凝土一维应力层裂实验的全场DIC分析 [J]. 力学学报, 2019, 51(4): 1064–1072. DOI: 10.6052/0459-1879-19-008.YU X L, FU Y Q, DONG X L, et al. Full field DIC analysis of one-dimensional spall strength for concrete [J]. Chinese Journal of Theoretical and Applied Mechanics, 2019, 51(4): 1064–1072. DOI: 10.6052/0459-1879-19-008. [7] LIU Z Y, ZHANG X X, MAO Y W, et al. Locally resonant sonic materials [J]. Science, 2000, 289(5485): 1734–1736. DOI: 10.1126/science.289.5485.1734. [8] LIU Z Y, CHAN C T, SHENG P. Analytic model of phononic crystals with local resonances [J]. Physical Review B, 2005, 71(1): 014103. DOI: 10.1103/PhysRevB.71.014103. [9] MITCHELL S J, PANDOLFI A, ORTIZ M. Metaconcrete: designed aggregates to enhance dynamic performance [J]. Journal of the Mechanics and Physics of Solids, 2014, 65: 69–81. DOI: 10.1016/j.jmps.2014.01.003. [10] MITCHELL S J, PANDOLFI A, ORTIZ M. Investigation of elastic wave transmission in a metaconcrete slab [J]. Mechanics of Materials, 2015, 91: 295–303. DOI: 10.1016/j.mechmat.2015.08.004. [11] 张恩, 路国运, 杨会伟, 等. 超材料混凝土的带隙特征及对冲击波的衰减效应 [J]. 爆炸与冲击, 2020, 40(6): 063301. DOI: 10.11883/bzycj-2019-0252.ZHANG E, LU G Y, YANG H W, et al. Band gap features of metaconcrete and shock wave attenuation in it [J]. Explosion and Shock Waves, 2020, 40(6): 063301. DOI: 10.11883/bzycj-2019-0252. [12] JIN H X, HAO H, HAO Y F, et al. Predicting the response of locally resonant concrete structure under blast load [J]. Construction and Building Materials, 2020, 252: 118920. DOI: 10.1016/j.conbuildmat.2020.118920. [13] XU C, CHEN W, HAO H, et al. Static mechanical properties and stress wave attenuation of metaconcrete subjected to impulsive loading [J]. Engineering Structures, 2022, 263: 114382. DOI: 10.1016/j.engstruct.2022.114382. [14] OYELADE A, ABIODUN Y, SADIQ M O. Dynamic behaviour of concrete containing aggregate resonant frequency [J]. Journal of Computational Applied Mechanics, 2018, 49(2): 380–385. DOI: 10.22059/JCAMECH.2018.269048.339. [15] HUANG H H, SUN C T, HUANG G L. On the negative effective mass density in acoustic metamaterials [J]. International Journal of Engineering Science, 2009, 47(4): 610–617. DOI: 10.1016/j.ijengsci.2008.12.007. [16] LIU Z Y, CHAN C T, SHENG P. Three-component elastic wave band-gap material [J]. Physical Review B, 2002, 65(16): 165116. DOI: 10.1103/PhysRevB.65.165116. [17] 吴健, 白晓春, 肖勇, 等. 一种多频局域共振型声子晶体板的低频带隙与减振特性 [J]. 物理学报, 2016, 65(6): 064602. DOI: 10.7498/aps.65.064602.WU J, BAI X C, XIAO Y, et al. Low frequency band gaps and vibration reduction properties of a multi-frequency locally resonant phononic plate [J]. Acta Physica Sinica, 2016, 65(6): 064602. DOI: 10.7498/aps.65.064602. [18] EURO C. CEB-FIP model code 1990 [Z]. Lausanne, Switzerland: Thomas TelFord Sevices Ltd., 1993. DOI: 10.1680/ceb-fipmc1990.35430. [19] MALVAR L J, CRAWFORD J E. Dynamic increase factors for concrete [R]. Port Hueneme CA: Naval Facilities Engineering Service Center, 1998. [20] LI J, HAO H. Numerical study of concrete spall damage to blast loads [J]. International Journal of Impact Engineering, 2014, 68: 41–55. DOI: 10.1016/j.ijimpeng.2014.02.001. [21] WU H J, ZHANG Q M, HUANG F L, et al. Experimental and numerical investigation on the dynamic tensile strength of concrete [J]. International Journal of Impact Engineering, 2005, 32(1): 605–617. DOI: 10.1016/j.ijimpeng.2005.05.008.