Rezapour Moein, Ghassemieh Mehdi, Motavalli Masoud, Shahverdi Moslem
School of Civil Engineering, University of Tehran, 16th Azar Street, Tehran 11155-4563, Iran.
Swiss Federal Laboratories for Materials Science and Technology, Empa, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
Materials (Basel). 2021 May 30;14(11):2961. doi: 10.3390/ma14112961.
This study presents a new way to improve masonry wall behavior. Masonry structures comprise a significant part of the world's structures. These structures are very vulnerable to earthquakes, and their performances need to be improved. One way to enhance the performances of such types of structures is the use of post-tensioning reinforcements. In the current study, the effects of shape memory alloy as post-tensioning reinforcements on originally unreinforced masonry walls were investigated using finite element simulations in Abaqus. The developed models were validated based on experimental results in the literature. Iron-based shape memory alloy strips were installed on masonry walls by three different configurations, namely in cross or vertical forms. Seven macroscopic masonry walls were modeled in Abaqus software and were subjected to cyclic loading protocol. Parameters such as stiffness, strength, durability, and energy dissipation of these models were then compared. According to the results, the Fe-based strips increased the strength, stiffness, and energy dissipation capacity. So that in the vertical-strip walls, the stiffness increases by 98.1%, and in the cross-strip model's position, the stiffness increases by 127.9%. In the vertical-strip model, the maximum resistance is equal to 108 kN, while in the end cycle, this number is reduced by almost half and reaches 40 kN, in the cross-strip model, the maximum resistance is equal to 104 kN, and in the final cycle, this number decreases by only 13.5% and reaches 90 kN. The scattering of Fe-based strips plays an important role in energy dissipation. Based on the observed behaviors, the greater the scattering, the higher the energy dissipation. The increase was more visible in the walls with the configuration of the crossed Fe-based strips.
本研究提出了一种改善砌体墙性能的新方法。砌体结构在世界建筑结构中占很大一部分。这些结构极易受到地震影响，其性能需要改进。提高这类结构性能的一种方法是使用后张法加固。在本研究中，使用Abaqus中的有限元模拟研究了形状记忆合金作为后张法加固对原始无筋砌体墙的影响。所开发的模型根据文献中的实验结果进行了验证。铁基形状记忆合金条通过三种不同的配置安装在砌体墙上，即交叉或垂直形式。在Abaqus软件中对七面宏观砌体墙进行了建模，并使其承受循环加载协议。然后比较了这些模型的刚度、强度、耐久性和能量耗散等参数。根据结果，铁基条提高了强度、刚度和能量耗散能力。在垂直条墙中，刚度增加了98.1%，在交叉条模型位置，刚度增加了127.9%。在垂直条模型中，最大阻力等于108kN，而在最后一个循环中，这个数字几乎减半，达到40kN，在交叉条模型中，最大阻力等于104kN，在最后一个循环中，这个数字仅下降13.5%，达到90kN。铁基条的分散在能量耗散中起重要作用。根据观察到的行为，分散越大，能量耗散越高。在交叉铁基条配置的墙体中，这种增加更为明显。
