Delamination Damage Detection in Laminated Composite by LDR-Based Multi-frequency Method

基于LDR多频信息融合的复合材料分层缺陷检测

Local defected resonance(LDR)is a recently-developed non-destructive testing method,which identifies damage by detecting the vibrational response of the structural surface under the wideband ultrasonic excitation. The concept of LDR is studied and applied for damage imaging of delamination in composite laminates. Aiming at the problem of poor anti-noise ability and inaccurate damage identification in traditional detection process,an LDR-based multi-frequency method is proposed. Experimental results show that the proposed method can realize the localization and imaging of delamination damage in composite materials.

缺陷局部共振(Local defect resonance,LDR)方法是近年来提出的一种基于结构振动特征识别的新型无损检测技术,通过检测结构表面在宽频超声信号激励下的振动响应特征来识别损伤。为此基于LDR效应,对有分层缺陷的复合材料层合板进行检测。针对传统的依据LDR振型进行损伤检测的方法抗噪能力较差以及缺陷面积识别不准确的问题,提出了近LDR频带的多频损伤信息融合方法。实验结果表明,利用所提出的方法可显著提高损伤识别过程中的抗噪能力,实现复合材料层合板中分层缺陷的准确定位和成像。