An integrated numerical model for investigating guided waves in impact-damaged composite laminates

Abstract

This paper presents a novel numerical technique that combines predictions of impact-induced damage and subsequent ultrasonic guided-wave propagation in composite laminates, with emphasis on the development and verification of the modelling framework. Delamination and matrix cracking are considered in the modelling technique, which is validated by experimental measurements on a carbon-fibre/epoxy plate using a drop-weight impact tower and a scanning laser vibrometer. Good agreement has been found between simulations and experiments regarding the impact response and globallocal wavefields. Effects of these two damage modes, damage extent and multiple impacts on guided waves are studied using the modelling tool. Matrix cracking leads to lower wavefield scattering compared with delamination, particularly in un-damaged regions.The modelling strategy can provide valuable guidelines for optimising health-monitoring arrangements on composite structures that are susceptible to impacts, and the guidedwave model can also be integrated with other numerical models for predicting internal flaws in composite laminates.

3D Modelling of the Scattering of the Fundamental Anti-Symmetric Lamb Mode (A0) Propagating within a Point-Impacted Transverse-Isotropic Composite Plate

“…With S 0 being three times faster than A 0 , one can easily choose the propagating distance to avoid any overlapping between the generated modes. Furthermore, the ratio of amplitudes between S 0 to A 0 is around 4%, which suggests neglecting the S 0 contribution, in accordance with the literature [25]. Therefore, the received mode will be almost a pure A 0 mode with negligible interference of the S 0 mode.…”

“…The delamination reshapes the wavefield in the damaged and undamaged regions. In particular, it was found that the contribution of the delamination in the scattered wavefield is ~50% higher than the one corresponding to the matrix cracks [25].…”

“…Different techniques and approaches have been used in order to model the propagation of ultrasonic guided waves within impacted composite plates. Zhang et al proposed a modelling that combines low-velocity impact damage with the analysis of guided wave propagation, where delamination and matrix cracking are both directly meshed in the guided-wave model [25]. However, different types of damage could be created when composites are submitted to a low velocity impact.…”

Characterization of multilayer delaminations in composites using wavenumber analysis: numerical and experimental studies

“…Previous investigators have reported the use of numerical simulations to study guided wave propagation and interaction with delaminations. [35][36][37][38][39][40][41][42][43][44] Guo and Cawley 35 used a two-dimensional (2D) finite element method (FEM) with plane strain assumption to study the reflection of the S0 mode from a delamination in unidirectional and cross-ply laminates. Ramadas et al 36,37 investigated the A0 mode interaction with the symmetric and asymmetric delaminations using a 2D model.…”

“…Leckey and Seebo 42 conducted a preliminary simulation to investigate differences in trapped energy for multilayer delaminations, and their studies showed that the trapped energy increases at the composite surface when additional delaminations exist through the composite thickness. In addition, 3D modeling of guided wave propagation and interaction with the actual impact damage was investigated in Leckey et al 43 and Zhang et al 44 These studies have facilitated our understanding of guided wave-based delamination detection using wavefield analysis. However, the numerical and experimental characterization of guided wave interactions with multilayer delaminations using wavenumber analysis and their sensitivity to the delamination severity are very limited.…”