Experimental and three-dimensional mesoscopic investigation of coral aggregate concrete under dynamic splitting-tensile loading
Experimental and three-dimensional mesoscopic investigation of coral aggregate concrete under dynamic splitting-tensile loading
复制标题
动态劈裂拉伸荷载作用下珊瑚骨料混凝土的实验及三维细观研究
DOI：
10.1617/s11527-020-1447-5
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发表时间：
2020-02-03
影响因子：
3.8
通讯作者：
Yue, Chengjun
中科院分区：
文献类型：
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作者：
Ma, Haiyan;Wu, Zhangyu;Yue, Chengjun
采用试验和细观模拟相结合的方法，研究了珊瑚骨料混凝土（CAC）的动态劈拉性能。采用MTS试验机和Split-Hopkinson压杆装置，分别对不同单轴抗压强度（30-70 MPa）的CAC进行了静、动态劈拉强度和破坏形态的试验研究。本文建立了一个三维随机细观模型，模拟了不同应变率（1-200 s-1）条件下CAC的劈拉强度和破坏，并通过对比试验和数值计算结果进行了验证。试验和数值计算结果表明，混凝土强度和应变率对劈拉强度和破坏形态有显著影响。从混凝土和骨料的局部化破坏形态解释了试件外部破坏比内部严重、试件中心断裂比边缘严重的动态劈裂破坏机理。此外，还可以看出，CAC的拉伸动力增加因子对应变率的敏感性显著，这对进一步研究礁CAC结构具有重要意义。
An investigation that combines both experimental tests and mesoscopic modelling is conducted to characterize the dynamic splitting-tensile behavior of coral aggregate concrete (CAC). Static and dynamic splitting-tensile strength and failure patterns of CAC with different uniaxial compressive strength (30–70 MPa) are tested by means of MTS machine and Split-Hopkinson pressure bar device, respectively. A three-dimensional (3D) randomly mesoscopic model for the simulation of the splitting-tensile strength and failure of CAC under different strain rates (1–200 s−1) is developed and validated by contrasting tested and numerical results. The experimental and numerical results indicate that the splitting-tensile strength and failure pattern are significantly affected by concrete strength and strain rate. The dynamic splitting failure mechanism that the damage outside the specimen is more serious than the inside, and the fracture in the center of the specimen is more severe than the edge, has been explained from the localized failure patterns of concrete and aggregates. Furthermore, it can be learned from the tensile dynamic increase factor of CAC is sensitive to strain rate significantly, which has a profound significance in the further investigation of reef CAC structures.