Integrating Fiber Overbraids in Hybrid Composites for Enhanced Compressive Performance
Topic(s) : Special Sessions
Co-authors :
Iheoma C. NWUZOR (UNITED KINGDOM), Laura Rhian PICKARD (UNITED KINGDOM), Nicolas DARRAS (UNITED KINGDOM), Bohao ZHANG , Giuliano ALLEGRI , Michael R. WISNOM (FRANCE), Richard S. TRASK (UNITED KINGDOM)Abstract :
The development of hybrid composites offers a viable route toward structural material advancement, combining various fibrous and matrix elements for synergistic beneficial effects. Fibre-reinforced composites are extensively used in high-performance applications for their remarkable strength-to-weight ratios. The compressive performance of composites is essentially controlled by fibre misalignment that can cause micro buckling. Several research studies have been reported on braided fibre-reinforced composites [1-3]. However, to improve the compressive performance of polymer composites, this study aims to investigate a novel synergistic hierarchical structured approach which combines hybridized fibre overbraids (FOBs) with single rod and rod-bundle architectures (Fig.1).
In this study, fibre hybridization was extensively investigated on different FOBs, configurations, lay lengths and fibre volume fractions to obtain the most promising over-braiding architecture to maximize compressive performance. Consequently, FOB structures with high performance were judiciously integrated using epoxy resin in to maximize their resistance to compressive failures. This was achieved using a pultruded rod of 0.8 mm diameter as the core component of the FOB architecture. A Resin Transfer Moulding (RTM) manufacturing technique was employed for the infiltration of the dry preform as shown in the experimental setup detailed in Fig. 2. This method involved the controlled injection of liquid resin into a mould containing the fibre overbraided rod bundles at a controlled pressure at 50 oC and maintains a similar standard composite density within the range [4]. The material samples were subjected to Non-Destructive Testing (NDT), via micro CT scan to determine the position and volume of the interior defects and rank the specimens’ integrity once subjected to compressive loading. The compressive performance of the different material hybrid combinations was assessed using a test method developed by the University of Bristol (based on buckling) to measure the compressive strength and modulus of elasticity of the manufactured struts under controlled conditions. Strain gauges and Digital Image Correlation (DIC) were used to determine the strain, displacement and deformation of the material during mechanical evaluation.
In conclusion, the designed approach used in this study demonstrated an adaptable and easily implementable way to enhance the compressive performance of overbraided continuous fibre-reinforced composite systems. In the future, this method offers the potential to create a novel class of hybrid composite materials to meet the demands of different industrial applications.
In this study, fibre hybridization was extensively investigated on different FOBs, configurations, lay lengths and fibre volume fractions to obtain the most promising over-braiding architecture to maximize compressive performance. Consequently, FOB structures with high performance were judiciously integrated using epoxy resin in to maximize their resistance to compressive failures. This was achieved using a pultruded rod of 0.8 mm diameter as the core component of the FOB architecture. A Resin Transfer Moulding (RTM) manufacturing technique was employed for the infiltration of the dry preform as shown in the experimental setup detailed in Fig. 2. This method involved the controlled injection of liquid resin into a mould containing the fibre overbraided rod bundles at a controlled pressure at 50 oC and maintains a similar standard composite density within the range [4]. The material samples were subjected to Non-Destructive Testing (NDT), via micro CT scan to determine the position and volume of the interior defects and rank the specimens’ integrity once subjected to compressive loading. The compressive performance of the different material hybrid combinations was assessed using a test method developed by the University of Bristol (based on buckling) to measure the compressive strength and modulus of elasticity of the manufactured struts under controlled conditions. Strain gauges and Digital Image Correlation (DIC) were used to determine the strain, displacement and deformation of the material during mechanical evaluation.
In conclusion, the designed approach used in this study demonstrated an adaptable and easily implementable way to enhance the compressive performance of overbraided continuous fibre-reinforced composite systems. In the future, this method offers the potential to create a novel class of hybrid composite materials to meet the demands of different industrial applications.