Department of Fundamentals of Machinery Design, Faculty of Mechanical Engineering, Silesian University of Technology, Konarskiego 18A, 44-100 Gliwice, Poland.
Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia.
Sensors (Basel). 2021 Dec 14;21(24):8342. doi: 10.3390/s21248342.
The problem of characterizing the structural residual life is one of the most challenging issues of the damage tolerance concept currently applied in modern aviation. Considering the complexity of the internal architecture of composite structures widely applied for aircraft components nowadays, as well as the additional complexity related to the appearance of barely visible impact damage, prediction of the structural residual life is a demanding task. In this paper, the authors proposed a method based on detection of structural damage after low-velocity impact loading and its classification with respect to types of acting stress on constituents of composite structures using the developed processing algorithm based on segmentation of 3D X-ray computed tomograms using the package, real-oriented dual-tree wavelet transform and supporting image processing procedures. The presented algorithm allowed for accurate distinguishing of defined types of damage from X-ray computed tomograms with strong robustness to noise and measurement artifacts. The processing was performed on experimental data obtained from X-ray computed tomography of a composite structure with barely visible impact damage, which allowed better understanding of fracture mechanisms in such conditions. The gained knowledge will allow for a more accurate simulation of structural damage in composite structures, which will provide higher accuracy in predicting structural residual life.
表征结构剩余寿命的问题是当前现代航空中应用的损伤容限概念中最具挑战性的问题之一。考虑到当今广泛应用于飞机部件的复合材料结构的内部结构的复杂性，以及与几乎不可见的冲击损伤出现相关的额外复杂性，预测结构剩余寿命是一项艰巨的任务。在本文中，作者提出了一种方法，该方法基于在复合材料结构的组成部分上的作用应力的类型对低速冲击载荷后的结构损伤进行检测和分类，该方法使用基于的 3D X 射线计算机断层扫描分割的开发处理算法、面向实值的双树小波变换和支持图像处理过程。所提出的算法允许从 X 射线计算机断层扫描中准确区分定义的损伤类型，并且对噪声和测量伪影具有很强的鲁棒性。该处理是在复合材料结构带有几乎不可见的冲击损伤的 X 射线计算机断层扫描实验数据上进行的，这使得在这种情况下更好地理解了断裂机制。所获得的知识将允许更准确地模拟复合材料结构中的结构损伤，从而在预测结构剩余寿命方面提供更高的准确性。
