Fibre direction and stacking sequence measurement in carbon fibre composites using Radon transforms of ultrasonic data

Abstract

Stacking sequence and, more generally, fibre orientation, are critical parameters in fibrous composite materials since they govern mechanical performance. This paper presents a method, based on the ultrasonic pulse-echo non-destructive technique, that can map the stacking sequence in unidirectional carbon-fibre composites. In-plane fibre orientation is measured using a Radon-transform method applied to local 2D images extracted from the 3D dataset formed from a 2D scan of pulse-echo responses. The ability to align these local 2D images to the plies in the region being assessed makes this technique suitable even in laminates where out-of-plane ply wrinkling is present. The Radon-transform method is shown to provide interpretable stacking-sequence maps, allowing ply lay-up sequence and both in-plane waviness and out-of-plane wrinkling to be visualised and quantified.

Exploiting the optical reflectance behaviour of carbon fibre composites for low-cost inspection and orientations analysis

“…Common Non-Destructive Inspection (NDI) methods, such as ultrasound, are generally unable to determine fibre orientations due to resolution limitations. Although some effort has been made to characterise out-of-plane wrinkling inside continuous fibre reinforced composites with focussed probes [4,5] and laser ultrasound methods [6].…”

“…Common non-destructive inspection methods, such as ultrasound, are generally unable to determine fibre orientations due to resolution limitations. Although some effort has been made to characterise out-of-plane wrinkling inside continuous fibre reinforced composites with focussed probes 4,5 and laser ultrasound methods. 6 Some success for in-plane orientation measurement has also been reported using active thermography and ultrasonic spectroscopy with guided Lamb waves, 7 but was specific to a glass fibre sheet moulded compound (SMC) material reinforced by carbon fibre tapes.…”

Phase-contrast and dark-field imaging for the inspection of resin-rich areas and fiber orientation in non-crimp vacuum infusion carbon-fiber-reinforced polymers

“…Therefore, particularly for safety critical parts used in aviation and aerospace applications, fast and reliable non-destructive investigation methods are essential. X-ray microcomputed tomography (XCT) is a widely established method for damage detection and characterization in CFRP [4,5] but also other techniques such as ultrasonic testing [6][7][8] and thermography [9,10] have proven suitable for the detection of internal pores and defects. In contrast, the segmentation of resin-rich areas and carbon fiber bundles is more challenging as contrast between fibers and matrix material (resin) is usually insufficient using XCT.…”

A cooperative mobile robot and manipulator system (Co-MRMS) for transport and lay-up of fibre plies in modern composite material manufacture

“…Due to the requirement of accurate localisation and fibre orientation detection, an efficient vision system is of great importance for autonomous robotic system in advanced composite manufacturing. Fibre orientation detection is challenging due to the high surface reflectivity and fine weaving of the material, and thus, it has still predominantly been accomplished manually in practice [31,41]. Traditional machine vision methods for fibre orientation detection of textiles prefer to utilise diffused lighting [45], such as diffuse dome [39] and flat diffuse [22] illumination measuring techniques.…”