The role of interfacial properties on the intralaminar and interlaminar damage behaviour of unidirectional composite laminates: Experimental characterization and multiscale modelling

Abstract

The development of the latest generation of wide-body passenger aircraft has heralded a new era in the utilisation of carbon-fibre composite materials. One of the primary challenges facing future development programmes is the desire to reduce the extent of physical testing, required as part of the certification process, by adopting a 'certification by simulation' approach. A hierarchical bottom-up multiscale simulation scheme can be an efficient approach that takes advantage of the natural separation of length scales between different entities 2 (fibre/matrix, ply, laminate and component) in composite structures. In this work, composites with various fibre/matrix and interlaminar interfacial properties were fabricated using an autoclave under curing pressures ranging from 0 to 0.8 MPa. The microstructure (mainly void content and spatial distribution) and the mechanical properties of the matrix and fibre/matrix interface were measured, the latter by means of nano-indentation tests in matrix pockets, and fibre push-in tests. In addition, the macroscopic interlaminar shear strength was determined by means of three-points bend tests on short beams. To understand the influence of interfacial properties on the intralaminar failure behaviour, a high-fidelity microscale computational model is presented to predict homogenized ply properties under shear loading. Predicted ply material parameters are then transferred to a mesoscale composite damage model to reveal the interaction between intralaminar and interlaminar damage behaviour of composite laminates.

Micromechanical analysis of interlaminar crack propagation between angled plies in mode I tests

“…The material properties for the interface are presented in Table 3. Acknowledging the challenge in determining interfacial strength and toughness, the parameters used in this work are based on available experimental data [36,37,38] and on previous micromechanical simulations [21,24,39,40].…”

A multiscale methodology quantifying the sintering temperature‐dependent mechanical properties of oxide matrix composites

“…In addition, the interface fracture energies in the shear modes were set equal to the matrix cracking fracture energy, G IIc = 100 J/m 2 , a value similar to the one used . A sensitivity study of these values indicates their effect on material behavior was only limited in the damage propagation regime …”

“…26 A sensitivity study of these values indicates their effect on material behavior was only limited in the damage propagation regime. 29 The RVE was discretized using wedge and brick finite elements for fibers and matrix with full Gauss integration (C3D6 and C3D8). It consisted of %20 000 elements which represented a discretization fine enough to capture the large stress gradients between neighboring fibers.…”

Nonlinear-Elastic Orthotropic Material Modeling of an Epoxy-Based Polymer for Predicting the Material Behavior of Transversely Loaded Fiber-Reinforced Composites

“…As the micromechanical damage mechanism in transversally loaded UD plies is a key aspect of the damage of laminates, researchers have focused on the modeling of these phenomena in recent years (e.g., [5][6][7][8][9][10][11][12][13][14][15][16]). While having insight into the micro-scale damage mechanisms, micromechanical modeling is used for predicting the composite stiffnesses and strengths of FRP based on the known material behavior of the fibers and the matrix.…”