Direct tensile behavior of amorphous metallic fiber-reinforced cementitious composites: Effect of fiber length, fiber volume fraction, and strain rate
Direct tensile behavior of amorphous metallic fiber-reinforced cementitious composites: Effect of fiber length, fiber volume fraction, and strain rate
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DOI：
10.1016/j.compositesb.2019.107430
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发表时间：
2019-11-15
影响因子：
13.1
通讯作者：
Nam, Jeongsoo
中科院分区：
文献类型：
--
作者：
Kim, Hongseop;Kim, Gyuyong;Nam, Jeongsoo
研究了纤维长度、纤维体积分数和应变速率对非晶金属纤维增强水泥基复合材料（AFRCC）的影响。实验结果表明，在静态和高应变速率条件下，长度为30 mm的非晶金属纤维由于其表面粗糙、比表面积大、长径比大，与基体的结合性能优异。然而，由于纤维的薄板形状易受剪切力的影响，因此纤维不会从基质中拔出并发生断裂。另一方面，具有15 mm长度的非晶金属纤维由于低纵横比和混合纤维数量的增加而表现出与基体的结合效率降低，并且纤维从基体中被拉出。随着纤维长度的增加，拉伸强度，应变能力，和拉伸韧性增加，因为应力分散效果的增加，同时增加的内部结合力和交联反应范围内的矩阵。对于动态增加因子（DIF），具有30 mm长度的非晶金属纤维表现出断裂而不从基体中拔出。然而，具有15 mm长度的非晶金属纤维从基体中拉出，从而增加了受应变速率影响的纤维-基体界面的结合效率。因此，发现AFRCC-L15具有较高的拉伸强度、应变能力和拉伸韧性的DIF。
In this study, the effects of the fiber length, fiber volume fraction, and strain rate on amorphous metallic fiber-reinforced cementitious composites (AFRCCs) were investigated. The experimental results showed that the amorphous metallic fibers with a 30 mm length had excellent bonding performance with the matrix because of the rough fiber surface, large specific surface area, and high aspect ratio under both static and high strain rate conditions. The fibers, however, were not pulled out from the matrix and were subjected to fracture because the thin-plate shape of the fibers was vulnerable to shear force. On the other hand, the amorphous metallic fibers with a 15 mm length exhibited decreased bonding efficiency with the matrix because of the low aspect ratio and the increased number of mixed fibers, and the fibers were pulled out from the matrix. As the fiber length increased, the tensile strength, strain capacity, and tensile toughness increased because the stress dispersion effect increased alongside the increase in the internal binding force and the crosslinking reaction range inside the matrix. As for the dynamic increase factor (DIF), the amorphous metallic fibers with a 30 mm length exhibited fracture without being pulled out from the matrix. The amorphous metallic fibers with a 15 mm length, however, were pulled out from the matrix, thereby increasing the bonding efficiency of the fiber-matrix interface that is affected by the strain rate. Therefore, it was found that AFRCC-L15 had a higher DIF for the tensile strength, strain capacity, and tensile toughness.