Multifractal analysis of crack patterns in reinforced concrete shear walls
Multifractal analysis of crack patterns in reinforced concrete shear walls
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DOI：
10.1177/1475921715624502
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发表时间：
2016-01
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影响因子：
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通讯作者：
Arvin Ebrahimkhanlou;A. Farhidzadeh;S. Salamone
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文献类型：
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作者：
Arvin Ebrahimkhanlou;A. Farhidzadeh;S. Salamone
传统上，钢筋混凝土剪力墙的评估依赖于人工目视评估，这种评估既耗时又严重依赖于检查人员的技能。使用配备高分辨率摄像头和无线通信的飞行和爬行机器人来获取数字图像并进行高级图像处理以提取裂纹模式的自动化评估的发展，为实现基于从结构获取的视觉信号确定结构损坏的自动化系统铺平了道路。由于将裂纹模式与结构完整性相关联的研究很少（如果有的话），因此本文建议使用多重分形分析来分析裂纹模式。该方法首先在合成裂缝模式上进行测试，然后应用于在受控反向循环荷载作用下测试两个大型钢筋混凝土剪力墙时收集的一组实验数据。每个样本的结构响应数据用于将多重分形参数与两个样本的结构性能联系起来。注意到多重分形参数与裂纹模式的演化和机制之间的关系。结果表明，随着裂纹图案的延伸和生长，多重分形参数向更高的值移动。当机械响应显示出严重的刚度损失时，参数会跳跃。在本研究中，没有尝试自动化从图像中映射裂缝的过程。
Conventionally, the assessment of reinforced concrete shear walls relies on manual visual assessment which is time-consuming and depends heavily on the skills of the inspectors. The development of automated assessment employing flying and crawling robots equipped with high-resolution cameras and wireless communications to acquire digital images and advance image processing to extract crack patterns has paved the path toward implementing an automated system which determines structural damage based on visual signals acquired from structures. Since there are few, if any, studies to correlate crack patterns to structural integrity, this article proposes to analyze crack patterns using a multifractal analysis. The approach is initially tested on synthetic crack patterns, and then it is applied to a set of experimental data collected during the testing of two large-scale reinforced concrete shear wall subjected to controlled reversed cyclic loading. The structural response data available for each specimen are used to link the multifractal parameters with the structural performance of the two specimens. A relationship between the multifractal parameters and the crack patterns’ evolution and mechanism is noted. The results show that as the crack patterns extend and grow, multifractal parameters move toward higher values. The parameters jump as the mechanical response shows severe stiffness loss. In this study, no attempt is made to automate the process of mapping cracks from images.