Quasi-static – cyclic and fatigue properties of carbon-innegra/pineapple multi-material laminates

Abstract

Natural fiber-reinforced polymer composites possess impressive advantages; however, they often fall short of meeting the demand for high-strength applications. Consequently, hybrid composites, combining natural and synthetic fibers, have gained significant attention for their tailorable properties. In this study, carbon-innegra hybrid fabrics (CI) and pineapple fabrics were utilized to fabricate hybrid multi-material compo sites. The use of CI hybrid fabrics in hybrid composites has yet to be explored. Composite laminates with varied stacking sequences of CI and pineapple fabrics were developed. Mechanical testing demonstrated that composites with high-stiff materials as the skin layer exhibited superior tensile and flexural strengths of 136.28 MPa and 284.08 MPa, respectively. Complex mechanical analyses, including quasi-cyclic flexural analysis, revealed promising properties, with the composite showing a lower strain of 0.029 and a maximum flexural strength of 147.48 MPa after the 50th cycle. Dynamic mechanical analysis revealed that the storage modulus was almost similar for pure CI composites and with CI layers in the outer stacks. Fatigue analysis demonstrated the durability of the composites, with the CI outer stack exhibiting lower deformative strain at the 4×10^4th cycle. At the same time, the alternate sequence of CI and pineapple layers displayed enhanced energy absorption during puncture impact. These findings suggest that the developed composite holds promise for semi-structural applications, with the flexibility to adjust stacking sequences based on specific requirements. A motorcycle battery cover was fabricated using the composite with CI as the outer stack to validate its potential.