Detection and evaluation of barely visible impact damage in woven glass fabric reinforced polyamide 6.6/6 composite using ultrasonic imaging, X-ray tomography and optical profilometry

Abstract

The present experimental work investigates the response of woven glass fabric reinforced polyamide 6.6/6 subjected to drop weight impact loading. The main objective is the development and the introduction of a new experimental procedure/approach, based on different complementary detection techniques, that aims at investigating the damage induced by impact loading in thermoplastic woven fabric composites. The developed approach is intended to be generalized to other types of composite materials. The main idea is to assess all the experimental results obtained through the developed procedure with a direct investigation method. The latter consists in the Permanent Indentation (PI) measurement providing an indicator of the damage criticality in the composite sample. To this end, several non-destructive testing methods are carried-out and their experimental findings are analyzed and cross-linked. The identification of the different damage mechanisms, caused by the drop weight impact, is performed using X-Ray micro-computed tomography (µCT). C-scan ultrasonic investigation is conducted according to two types: transmission and reflection for the detection of the impact damage and the identification of the induced degradation area. B-scan imaging are then obtained through specific post-processing of the impacted surface to extract the permanent indentation (PI). The latter is validated through surface flatness measurement using the highly resolved 3D optical profilometry. The correlation between the X-Ray tomography results and the permanent indentation measurement is then established. It correlates the PI level with the damage mechanisms of a barely visible impact damage (BVID) in woven glass reinforced polyamide 6.6/6 composite.

Failure mechanism of Ω-shape 3D orthogonal woven composite component under transverse low-velocity impact and subsequent axial compression load

“…Different from the damage repairability of self-healing materials (Han et al., 2021; Zhou and Ju, 2019), permanent damages (Miqoi et al., 2020) are retained inside the fiber-reinforced epoxy resin composites after being subjected to impact loads, which directly affects the residual mechanical properties of composite structures. It is necessary to consider the irreversible deformation structure and material damage of LVI as the initial geometry boundary of the CAI model.…”

Constitutive modelling of a self-healing composite matrix polymer material

“…Due to a heterogeneous structure, it occurs at several length scales (laminate, lamina, fibre-matrix, interface etc.). In (Miqoi et al, 2021) it is shown that at low velocity impacts, matrix cracking occurs first.…”

Experimental and Numerical Analysis of Multiple Low-Velocity Impact Damages in a Glass Fibered Composite Structure

“…The engineering industry offers many methods for analyzing the defects in the structures. The NDT analysis of glass fibers using a combination of X-ray tomography, ultrasonic imaging, and optical proliferometry was proposed by Miqoi et al [ 7 ] and on carbon fibers using digital image correlation (DIC) and scanning electron microscopy by Sarasini et al [ 8 ], in addition to experimental compression after impact tests by Talreja et al [ 9 ]. SHM finds its way in detecting such impact damage by performing continuous health monitoring of structures 1.…”