ABSTRACT

A crack or any kind of damage induces a sharp discontinuity in the rotational displacement curve in a structure under load. However, if the beam is not loaded sufficiently or crack depth is very small, the discontinuity may not be possible to identify through conventional methods. This study proposes a non-destructive approach to reveal the presence of a crack in structural components based on the measurement of very small discontinuity in rotational displacement by employing a piezoelectric sensor (PZT). An analytical model of a statically loaded cracked beam with PZT attached to the beam is developed for various boundary conditions. The solution is obtained through Ritz approximation. Rotational displacements at different points along the length of the beam are determined. Subsequently, a finite element analysis on ABAQUS platform is carried out for comparison. The results obtained from these analyses are validated with the experimental data published in open literature. Two distinct techniques are employed to monitor the damage in slender and short length beams. the efficacy of the technique in the detection of small cracks in structure is established. It is also shown that the presence of multiple cracks in beams having various boundary conditions can be monitored by a single non-destructive investigation following the method.

摘要

裂纹或任何类型的损坏都会导致受载结构的旋转位移曲线出现明显的不连续性。但是，如果梁加载不充分或裂纹深度非常小，则可能无法通过常规方法识别不连续性。本研究提出了一种非破坏性方法，基于使用压电传感器 (PZT) 测量旋转位移的非常小的不连续性，揭示结构部件中是否存在裂纹。针对各种边界条件开发了一个带有 PZT 连接到梁的静载荷裂纹梁的分析模型。该解是通过 Ritz 近似获得的。确定沿梁长度的不同点的旋转位移。随后，在 ABAQUS 平台上进行有限元分析以进行比较。从这些分析中获得的结果得到了公开文献中公布的实验数据的验证。采用两种不同的技术来监测细长和短长度梁的损坏情况。确定了该技术在检测结构中的小裂纹方面的有效性。还表明，可以通过遵循该方法的单个非破坏性调查来监测具有各种边界条件的梁中多个裂纹的存在。确定了该技术在检测结构中的小裂纹方面的有效性。还表明，可以通过遵循该方法的单个非破坏性调查来监测具有各种边界条件的梁中多个裂纹的存在。确定了该技术在检测结构中的小裂纹方面的有效性。还表明，可以通过遵循该方法的单个非破坏性调查来监测具有各种边界条件的梁中多个裂纹的存在。