Quantitative Detection of Low Energy Impact Damage in a Sandwich Composite Wing

Abstract

This work describes damage detection in a foam core composite wing (1320 mm  152.4 mm  13.4 mm) following a series of low energy impacts. Thirteen impacts (68 J deposited energy) were applied at adjacent locations approximately 1/4 of the way out from the wing center. Following every one or two impacts, the wing was tested using static tip deflection and dynamic vibrational excitation. Static and dynamic strains were measured using eight fiber Bragg grating sensors. Dynamic acceleration was also monitored using three conventional accelerometers. The estimated bicoherence was used to detect the presence of damage-induced non-linearity in time-series data recorded from each sensor. Receiver operating characteristic (ROC) curves were constructed for each sensor based on 15 or more dynamic measurements made for each damage case. The ROC curves provide a quantitative, statistical approach to evaluating the damage detection capabilities of the various sensors.

Low-velocity impact damage monitoring of a sandwich composite wing

“…This article extends the damage quantification work on composite wing sections using FBG sensors initiated by Seaver et al (2010). A new feature selection methodology for impact damage detection and quantification using kernel method and a guided wave–based active sensing approach is developed.…”

Triple correlation for detection of damage-related nonlinearities in composite structures

“…In addition, detection of small delaminations in composite specimens is questionable, as discussed in [1]. Recent examples related to composite materials include studies of nonlinear response characteristics [45], reciprocity analysis [46,47], curvatures and mode shapes [48], modal filtering [49], nonlinear time series [50], nonlinear interactions [51] and higher-order spectra [40,52]. The latter is particularly attractive for the detection of small quadratic nonlinearities.…”

“…Recent examples in the field-related to composite materials-include studies based on higher harmonics generation [27][28][29], nonlinear Lamb waves [30], nonlinear vibro-acoustic wave modulations [31][32][33][34][35][36], non-classical, nonlinear modulation transfer [37], analysis of fast/slow dynamics [38] and bispectral analysis [39,40].…”