On the transverse shear failure in unidirectional fibre-hybrid composite laminae using periodic microstructures
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Giuseppe GIUSEPPE ROMANO (UNITED KINGDOM), Yang YANG YANG (UNITED KINGDOM), Kali KALI BABU-KATNAM , Zhenmin ZHENMIN ZOUAbstract :
Thermosetting composites are known for their poor damage tolerance, and in this context, fibre hybridization emerges as a cost-effective solution to enhance both structural performance and durability. Katnam et al. [1] experimentally proved that fibre hybridization, combining PP and glass fibre in epoxy, exhibits higher compressive residual strength (measured in compression after impact) compared to a non-hybrid glass/epoxy composite. This study delves into the matrix yielding and failure behaviour of a thermosetting unidirectional fibre-hybrid composite lamina, utilising repeating unit cells with periodic microstructures. The primary focus of this investigation is on the transverse failure of the fibre-hybrid composite lamina under transverse shear, fig. 1.
The chosen composite configuration involves a hexagonal fibre packing comprising glass, epoxy, and an idealised secondary fibre with fibre volume fractions set to 0.3 for each fibre type. This configuration is compared against its non-hybrid counterpart (i.e., glass/epoxy) with the fibre volume fraction set to 0.6, to explore the potential benefits and alterations in mechanical behaviour resulting from a diverse fibre composition. The idealised secondary fibre is assumed to have the same Poisson’s ratio as the glass fibre but with a different Young’s modulus. Material properties are taken from Yang, 2015, table 1. The analysis adopts a 2D plane-strain model, wherein micro-stress fields, transverse elastic modulus, and strength properties are estimated. To validate the model, results are compared against well-established analytical models (e.g., Chamis and Mori-Tanaka) and experimental data. The periodic microstructure is characterised by fibres with the same diameter, ensuring consistency throughout the composite with the implementation of periodic boundary conditions. Fibres are assumed to behave linearly elastically with no failure; no fibre failure is expected to take place. Perfect interfacial bonding between the fibre and matrix is assumed. A computational study was conducted using a Python script with Abaqus/Standard and Digimat. Matrix yielding is implemented using Drucker-Prager criteria. Thus, the behaviour of the fibre-hybrid laminate can be studied by comparing the homogenised lamina properties and the different transverse failure modes under the implemented failure criteria, respectively.
This study serves as a foundational step towards comprehending the impact of fibre hybridization on the micromechanical behaviour of unidirectional composite laminates. By utilising a periodic microstructure, this research endeavours to unravel the intricate interplay between various fibre types and their influence on the overall mechanical integrity of the composite material.
The chosen composite configuration involves a hexagonal fibre packing comprising glass, epoxy, and an idealised secondary fibre with fibre volume fractions set to 0.3 for each fibre type. This configuration is compared against its non-hybrid counterpart (i.e., glass/epoxy) with the fibre volume fraction set to 0.6, to explore the potential benefits and alterations in mechanical behaviour resulting from a diverse fibre composition. The idealised secondary fibre is assumed to have the same Poisson’s ratio as the glass fibre but with a different Young’s modulus. Material properties are taken from Yang, 2015, table 1. The analysis adopts a 2D plane-strain model, wherein micro-stress fields, transverse elastic modulus, and strength properties are estimated. To validate the model, results are compared against well-established analytical models (e.g., Chamis and Mori-Tanaka) and experimental data. The periodic microstructure is characterised by fibres with the same diameter, ensuring consistency throughout the composite with the implementation of periodic boundary conditions. Fibres are assumed to behave linearly elastically with no failure; no fibre failure is expected to take place. Perfect interfacial bonding between the fibre and matrix is assumed. A computational study was conducted using a Python script with Abaqus/Standard and Digimat. Matrix yielding is implemented using Drucker-Prager criteria. Thus, the behaviour of the fibre-hybrid laminate can be studied by comparing the homogenised lamina properties and the different transverse failure modes under the implemented failure criteria, respectively.
This study serves as a foundational step towards comprehending the impact of fibre hybridization on the micromechanical behaviour of unidirectional composite laminates. By utilising a periodic microstructure, this research endeavours to unravel the intricate interplay between various fibre types and their influence on the overall mechanical integrity of the composite material.