M. Rajesh

Bio: M. Rajesh is an academic researcher from VIT University. The author has contributed to research in topics: Natural fiber & Composite number. The author has an hindex of 11, co-authored 34 publications receiving 450 citations. Previous affiliations of M. Rajesh include National Institute of Technology, Karnataka.

Natural Fiber Composite for Structural Applications

Abstract: With emerging focus on sustainable product development researchers are now focusing on consumption of Natural Fibres (NF) directly or as reinforcement materials in polymer based materials. Natural fibers are being used since ages but in recent decades there exist a need to explore the properties of these fibres for varied applications subject to the requirement. Natural Fibre Reinforced Polymers (NFRP) are utilized in manufacturing several automotive, marine and aerospace low level structural applications. In order to use natural fibres in high level structural applications, it is necessary to understand the structural, mechanical and thermal properties of the fibre. But as the natural fibre are obtained in irregular size and shapes in their longitudinal direction and cross section its quite difficult to study their properties unlike advanced composites. Hydrophilic and hydrophobic properties of Natural Fibres (NF) distress the bonding interaction between the fibre and matrix. This chapter tries to analyse the different characteristics with respect to the application of Natural Fibers (NF) for real time applications and attempts to provide an insight for researchers and design engineers to understand the requirements of utilizing Natural Fibres Composites (NFC) for construction applications in future. This chapter also summarize the advantages of natural fibres on their bio degradability aspects.

Influence of glass fibre reinforced polymer composite pin reinforcement on shear and dynamic behaviour of composite joint manufactured through co-cure technique

Abstract: The co-cure technique efficiently joins composite components in wings, ailerons, skins, ribs and spars in aeronautical applications. The present study investigates the effect of through-thickness reinforcement of glass fibre reinforced polymer composite pin on shear and dynamic properties of co-cured composite joints. The experimental results exhibited that through-thickness reinforcement with 2% composite pin volume significantly improved the shear strength and elongation limit by 38.4% and 102.4% compared to unpinned joints. Furthermore, composite pin reinforcement changed the catastrophic failure of co-cured joints to progressive failure due to the tougher bridging traction of composite pins. The comparison of fractured surfaces exposed that debonding, composite pin pull-out and shear fracture of pins are the major failure mechanisms involved in enhanced shear strength and progressive failure of co-cured composite joints. The experimental modal analysis avowed that through-thickness reinforcement with 2% composite pin volume improved the fundamental natural frequency of the co-cure joints, while co-cure joint reinforced with higher volume (4%) of composite pins had higher damping value due to excessive fibre damage, which increased interaction between composite adherent and adhesive.

Biodegradation properties and thermogravimetric analysis of 3D braided flax PLA textile composites

Abstract: Recent advances in the development and application of bio-based (natural fiber and biopolymer) composites are gaining broad attention because the resulting polymer completely degrades and does not ...

Deformation characteristics of functionally graded composite panels using finite element approximation

Abstract: Finite element solutions to the static responses of functionally graded plates and shell panels are investigated in this chapter. The overall material properties of metal/ceramic functionally graded material are considered to be temperature independent and modeled via power-law based Voigt's material scheme. The present functionally graded curved panels are modeled and analyzed in the commercially available finite element tool ANSYS APDL via eight-noded serendipity element (SHELL281). The mesh refinement test is executed followed by the validation test by comparing the present results with the reported results. The influences of the volume fractions, boundary conditions, curvature ratios, and thickness ratios on the central deflections and the axial stresses of functionally graded curved shell panels are illustrated and discussed in detail.

Influence of manufacturing process and GFRP pin loading on shear and dynamic behaviour of composite joints

Abstract: ABSTRACT An efficient manufacturing technique and high-strength composite structures are essential in weight-sensitive applications. The current study examines the combined effect of manufacturing techniques and GFRP pin insertion on shear and dynamic behaviour of composite joints. Shear analysis revealed that shear strength of the composite joint is intensely reliant on their manufacturing technique and improved in order: secondary bonding (least effective), co-bonding method, and co-cure joining (highly effective). The fracture mode and joint strength are also reliant on the volume fraction of fibreglass pins. The free vibrational analysis asserted that co-cure joining with a 2% volume fraction of fibreglass pins increased the fundamental natural frequency of composite joints due to the formation of an extrinsic crack bridging zone in the adhesive layer developed a stronger interface between adherent and adhesive. The present study exposes that enhancement in shear properties and free vibrational behaviour can be achieved by selecting the proper manufacturing technique and appropriate volume of fibreglass pins. The co-cure joining with 2% volume fractions of fibreglass pins provided the greatest enhancement in shear properties and natural frequencies of composite joints.

Recent progress on natural fiber hybrid composites for advanced applications: A review

Abstract: Natural fibers, as replacement of engineered fibers, have been one of the most researched topics over the past years. This is due to their inherent properties, such as biodegradability, renewability and their abundant availability when compared to synthetic fibers. Synthetic fibers derived from finite resources (fossil fuels) and are thus, affected mainly by volatility oil prices and their accumulation in the environment and/or landfill sites as main drawbacks their mechanical properties and thermal properties surpass that of natural fibers. A combination of these fibers/fillers, as reinforcement of various polymeric materials, offers new opportunities to produce multifunctional materials and structures for advanced applications. This article intends to cover recent developments from 2013-up to date on hybrid composites, based on natural fibers with other fillers. Hybrid composites preparation and characterization towards their applicability in advanced applications and the current challenges are also presented.