Dynamic impact behaviors and constitutive model of super-fine stainless wire reinforced reactive powder concrete
Dynamic impact behaviors and constitutive model of super-fine stainless wire reinforced reactive powder concrete
复制标题
超细不锈钢丝增强活性粉末混凝土动态冲击行为及本构模型
DOI：
10.1016/j.conbuildmat.2018.07.027
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发表时间：
2018-09-30
影响因子：
7.4
通讯作者：
Ou, Jinping
中科院分区：
文献类型：
--
作者：
Dong, Sufen;Han, Baoguo;Ou, Jinping
通过分离式霍普金森压杆试验，研究了超细不锈钢丝增强活性粉末混凝土在应变率为94/S~926/S范围内的动态冲击行为。通过计算机断层扫描和扫描电子显微镜分析，揭示了SSW对RPC动态冲击性能的改善机理。试验结果表明，SSW增强RPC的动态冲击抗压强度随应变率的增加而提高。SSW降低了RPC的抗压强度动态增长系数，削弱了RPC的应变率加固效应。在305/S应变率下，SSW加固RPC的最大动态峰值应变达到34,070µepsilon，由于SSW的侧向约束作用，RPC的极限应变减小。SSW加固RPC的应力应变曲线分为弹性阶段、弹塑性阶段和下降阶段。加入SSW后，RPC的动态冲击韧性和冲击耗散能分别提高了43.5%和58.2%。增加SSW体积分数使更多的SSW抑制RPC中裂缝的产生和扩展，从而导致破坏程度的降低。束间锚固界面的形成提高了RPC对裂缝发展的抵抗能力。基于修正的粘弹性和损伤理论建立的动态冲击本构模型能够很好地描述不同应变率下SSW增强RPC的应力应变关系，其中应变门槛值同时由应变率和SSW体积分数决定。(C)2018爱思唯尔有限公司。保留所有权利。
The dynamic impact behavior of super-fine stainless wire (SSW) reinforced reactive powder concrete (RPC) was studied through split hopkinson pressure bar test with the strain rate range from 94/s to 926/s in this paper. The modification mechanisms of SSW to the dynamic impact performance of RPC were revealed via computed tomography and scanning electron microscope analysis. Experimental results showed that the dynamic impact compressive strength of SSW reinforced RPC increases with the strain rate. The dynamic increase factor of compressive strength is decreased and the strain-rate strengthening effect of RPC is weakened by SSW. The maximum dynamic peak strain of SSW reinforced RPC reaches up to 34,070 mu epsilon at the strain rate of 305/s. The limit strain of RPC is decreased because of the lateral confinement effect of SSW. The stress-strain curves of SSW reinforced RPC include elastic stage, elastic-plastic stage and descending stage. The addition of SSW leads 43.5% and 58.2% of increase in dynamic impact toughness and impact dissipate energy of RPC, respectively. Increasing SSW volume fraction makes more SSW to inhibit the generation and propagation of cracks in RPC, thus leading to the decrease of destruction degree. The formation of inter-anchored interface among bundling SSW increases the resistance of RPC to crack development. The dynamic impact constitutive model established on the basis of revised visco-elastic and damage theory can well describe the stress-strain relationship of SSW reinforced RPC at different strain rates, in which the strain threshold is governed by strain rate and SSW volume fraction simultaneously. (C) 2018 Elsevier Ltd. All rights reserved.