Ji Sang-Won, Yeon Yeong-Mo, Hong Ki-Nam
Department of Civil Engineering, Chungbuk National University, Cheongju 28644, Korea.
Materials (Basel). 2022 Feb 24;15(5):1703. doi: 10.3390/ma15051703.
In this study, the shear performance of a reinforced concrete (RC) beam with Fe-based shape memory alloy (Fe-SMA) stirrups was evaluated experimentally and analytically. Five specimens that had a possibility of shear failure under four-point loading were prepared. The major experimental variables were the spacings (300 and 200 mm) between the Fe-SMA stirrups and whether the stirrups were activated or non-activated. The shear strength of the specimen reinforced with the Fe-SMA stirrups at a spacing of 200 mm was 27.1% higher than that of the specimen reinforced at a spacing of 300 mm. The activation of the Fe-SMA stirrups, which produced active confining pressure, increased the shear strength by up to 7.6% and decreased the number of shear cracks compared to the case of the non-activated specimen. Therefore, the use of Fe-SMA stirrups could significantly improve the usability of concrete members by increasing their shear strength and initial stiffness and by controlling crack formation. Furthermore, finite element method (FEM) analysis was conducted using LS-DYNA, a commercial software program, to predict the shear performance of the RC beam reinforced with the Fe-SMA stirrups. The ultimate load and displacement of each specimen were predicted with errors less than 1.4 and 9.4%, respectively. Furthermore, the FEM predicted the change in failure mode and the stiffness improvement due to the activation of the Fe-SMA stirrups. Therefore, the proposed finite element analysis model can effectively predict the behavior of an RC beam reinforced with Fe-SMA stirrups.
在本研究中，对配置铁基形状记忆合金（Fe-SMA）箍筋的钢筋混凝土（RC）梁的抗剪性能进行了试验和分析评估。制备了五个在四点加载下可能发生剪切破坏的试件。主要试验变量为Fe-SMA箍筋之间的间距（300和200mm）以及箍筋是否激活。间距为200mm的Fe-SMA箍筋增强试件的抗剪强度比间距为300mm的增强试件高27.1%。与未激活试件相比，激活产生主动围压的Fe-SMA箍筋可使抗剪强度提高7.6%，并减少剪切裂缝数量。因此，使用Fe-SMA箍筋可通过提高混凝土构件的抗剪强度和初始刚度以及控制裂缝形成来显著提高其适用性。此外，使用商业软件程序LS-DYNA进行了有限元方法（FEM）分析，以预测配置Fe-SMA箍筋的RC梁的抗剪性能。各试件的极限荷载和位移预测误差分别小于1.4%和9.4%。此外，有限元方法预测了由于Fe-SMA箍筋激活导致的破坏模式变化和刚度提高。因此，所提出的有限元分析模型能够有效地预测配置Fe-SMA箍筋的RC梁的性能。
