Purpose

The purpose of this paper is to introduce a methodology aimed to detect debonding induced by low impacts energies in typical aeronautical structures. The methodology is based on high frequency sensors/actuators system simulation and the application of elliptical triangulation (ET) and probability ellipse (PE) methods as damage detector. Numerical and experimental results on small-scale stiffened panels made of carbon fiber-reinforced plastic material are discussed.

Design/methodology/approach

The damage detection methodology is based on high frequency sensors/actuators piezoceramics system enabling the ET and the PE methods. The approach is based on ultrasonic guided waves propagation measurement and simulation within the structure and perturbations induced by debonding or impact damage that affect the signal characteristics.

Findings

The work is focused on debonding detection via test and simulations and calculation of damage indexes (DIs). The ET and PE methodologies have demonstrated the link between the DIs and debonding enabling the identification of position and growth of the damage.

Originality/value

The debonding between two structural elements caused in manufacturing or in-service is very difficult to detect, especially when the components are in low accessibility areas. This criticality, together with the uncertainty of long-term adhesive performance and the inability to continuously assess the debonding condition, induces the aircrafts’ manufacturers to pursuit ultraconservative design approach, with in turn an increment in final weight of these parts. The aim of this research’s activity is to demonstrate the effectiveness of the proposed methodology and the robustness of the structural health monitoring system to detect debonding in a typical aeronautical structural joint.

中文翻译：

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先进的航空航天复合结构脱粘检测技术

目的

本文的目的是介绍一种方法，旨在检测典型航空结构中由低冲击能量引起的脱粘。该方法基于高频传感器/执行器系统模拟以及椭圆三角测量 (ET) 和概率椭圆 (PE) 方法作为损伤检测器的应用。讨论了由碳纤维增强塑料材料制成的小型加筋板的数值和实验结果。

设计/方法/方法

损坏检测方法基于支持 ET 和 PE 方法的高频传感器/执行器压电陶瓷系统。该方法基于超声波导波在结构内的传播测量和模拟，以及由影响信号特性的脱粘或冲击损伤引起的扰动。

发现

这项工作的重点是通过测试和模拟以及损伤指数 (DI) 的计算来检测脱粘。ET 和 PE 方法已经证明了 DI 和剥离之间的联系，能够识别损坏的位置和增长。

原创性/价值

在制造或使用中引起的两个结构元件之间的脱粘非常难以检测，尤其是当组件位于低可达区域时。这种临界性，加上长期粘合性能的不确定性和无法持续评估脱粘条件，促使飞机制造商追求超保守的设计方法，从而增加这些部件的最终重量。本研究活动的目的是证明所提出的方法的有效性和结构健康监测系统的稳健性，以检测典型航空结构接头中的脱粘。