Toughening the Epoxy Matrix of Fibre Composites with Rigid and Soft Nanomaterials
Topic(s) : Special Sessions
Co-authors :
Wenkai CHANG , Louis ROSE (AUSTRALIA), Anthony KINLOCH (UNITED KINGDOM), Chun WANG (AUSTRALIA)Abstract :
Toughening the Epoxy Matrix of Fibre Composites with Rigid and Soft Nanomaterials
Wenkai Chang1, Francis Rose1, Anthony Kinloch2, Chun Wang1
1 School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
2 Department of Mechanical Engineering, Imperial College of London, UK.
Toughening the epoxy matrix of fibre-reinforced composites using nanoparticles is an effective strategy to extend their applications in extreme environments, such as storing liquid hydrogen. Recent experimental studies have demonstrated that the fracture toughness of epoxies and their composites can be effectively enhanced by incorporating nanoparticles, either stiffer or softer than the matrix material. At room temperature, the toughening of nanoparticles has been attributed to different mechanisms, with debonding and cavitation being the primary mechanism for rigid (stiffer) particles or soft particles, respectively. However, there is a lack of understanding of how the modulus of the nanoparticles affects the toughening efficacy, especially at cryogenic temperatures where thermal residual stresses and reduced matrix toughness can affect how the different mechanisms contribute to the overall toughening. Existing models mostly consider the case of perfectly rigid particles or open voids.
This study presents an investigation of the effects of the stiffness of the nanoparticles on the toughening efficiency at room and cryogenic temperatures. Experimental investigations and multiscale modelling have been carried out to understand how the nanomaterial’s stiffness affects the different toughening mechanisms, which include debonding, void growth, and shear banding of the surrounding matrix. A cohesive zone model is employed to model the particle-matrix interface, which leads naturally to a size effect for toughening for a given stiffness.
The modelling results reveal, for the first time, the presence of optimum particle stiffnesses that yield the highest toughening effect in both low- and high-stiffness ranges. The modelling results are compared with available experimental observations, demonstrating that the multi-scale modelling approach can quantitatively predict the effect of nanoparticle stiffness on the toughening of epoxies. As a result, this multi-scale model offers a powerful tool for optimising and identifying novel toughening strategies for enhancing the performance of fibre composites such as the storage of cryogenic liquid hydrogen for the advancement of net-zero aviation.
Wenkai Chang1, Francis Rose1, Anthony Kinloch2, Chun Wang1
1 School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia
2 Department of Mechanical Engineering, Imperial College of London, UK.
Toughening the epoxy matrix of fibre-reinforced composites using nanoparticles is an effective strategy to extend their applications in extreme environments, such as storing liquid hydrogen. Recent experimental studies have demonstrated that the fracture toughness of epoxies and their composites can be effectively enhanced by incorporating nanoparticles, either stiffer or softer than the matrix material. At room temperature, the toughening of nanoparticles has been attributed to different mechanisms, with debonding and cavitation being the primary mechanism for rigid (stiffer) particles or soft particles, respectively. However, there is a lack of understanding of how the modulus of the nanoparticles affects the toughening efficacy, especially at cryogenic temperatures where thermal residual stresses and reduced matrix toughness can affect how the different mechanisms contribute to the overall toughening. Existing models mostly consider the case of perfectly rigid particles or open voids.
This study presents an investigation of the effects of the stiffness of the nanoparticles on the toughening efficiency at room and cryogenic temperatures. Experimental investigations and multiscale modelling have been carried out to understand how the nanomaterial’s stiffness affects the different toughening mechanisms, which include debonding, void growth, and shear banding of the surrounding matrix. A cohesive zone model is employed to model the particle-matrix interface, which leads naturally to a size effect for toughening for a given stiffness.
The modelling results reveal, for the first time, the presence of optimum particle stiffnesses that yield the highest toughening effect in both low- and high-stiffness ranges. The modelling results are compared with available experimental observations, demonstrating that the multi-scale modelling approach can quantitatively predict the effect of nanoparticle stiffness on the toughening of epoxies. As a result, this multi-scale model offers a powerful tool for optimising and identifying novel toughening strategies for enhancing the performance of fibre composites such as the storage of cryogenic liquid hydrogen for the advancement of net-zero aviation.