Choi Eusoo, Ho Ha-Vinh, Seo Junwon
Department of Civil and Environmental Engineering, Hongik University, Seoul 04066, Korea.
Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA.
Materials (Basel). 2021 Aug 30;14(17):4933. doi: 10.3390/ma14174933.
In this study, a compressive impact test was conducted using the split Hopkinson pressure bar (SHPB) method to investigate SMA fiber-reinforced mortar's impact behavior. A 1.5% fiber volume of crimped fibers and dog-bone-shaped fibers was used, and half of the specimens were heated to induce recovery stress. The results showed that the appearance of SMA fibers, recovery stress, and composite capacity can increase strain rate. For mechanical properties, the SMA fibers reduced dynamic compressive strength and increased the peak strain. The specific energy absorption of the reinforced specimens slightly increased due to the addition of SMA fibers and the recovery stress; however, the effect was not significant. The composite behavior between SMA fibers and the mortar matrix, however, significantly influenced the dynamic compressive properties. The higher composite capacity of the SMA fibers produced lower dynamic compressive strength, higher peak strain, and higher specific energy absorption. The composite behavior of the dog-bone-shaped fiber was less than that of the crimped fiber and was reduced due to heating, while that of the crimped fiber was not. The mechanical properties of the impacted specimen followed a linear function of strain rate ranging from 10 to 17 s; at the higher strain rates of about 49-67 s, the linear functions disappeared. The elastic modulus of the specimen was independent of the strain rate, but it was dependent on the correlation between the elastic moduli of the SMA fibers and the mortar matrix.
在本研究中，采用分离式霍普金森压杆（SHPB）方法进行了压缩冲击试验，以研究形状记忆合金（SMA）纤维增强砂浆的冲击行为。使用了纤维体积分数为1.5%的卷曲纤维和狗骨形纤维，并且将一半的试样加热以诱导恢复应力。结果表明，SMA纤维的存在、恢复应力和复合能力均可提高应变率。就力学性能而言，SMA纤维降低了动态抗压强度并增加了峰值应变。由于添加了SMA纤维和恢复应力，增强试样的比能量吸收略有增加；然而，效果并不显著。然而，SMA纤维与砂浆基体之间的复合行为显著影响了动态压缩性能。SMA纤维较高的复合能力导致较低的动态抗压强度、较高的峰值应变和较高的比能量吸收。狗骨形纤维的复合行为小于卷曲纤维，并且由于加热而降低，而卷曲纤维则没有。冲击试样的力学性能在应变率为10至17 s时遵循线性函数；在约49 - 67 s的较高应变率下，线性函数消失。试样的弹性模量与应变率无关，但它取决于SMA纤维和砂浆基体弹性模量之间的相关性。
