Indian Institute of Science (IISc)
Doctor of Philosophy - PhD, Aerospace engineering
Jul 2012 - May 2020
Master of Engineering - Aeronautical Engineering
Aug 2010 - Jun 2012
Park College of Engineering and Technology logo
Park College of Engineering and TechnologyPark College of Engineering and Technology
Bachelor of Engineering - BE, Aeronautical Engineering
2006 - May 2010
RESEARCH INTERESTS
spray characterization of aerospace injectors, low and high-speed aerodynamics, turbomachines etc.
16
Scopus Publications
11
Scholar Citations
2
Scholar h-index
Scopus Publications
Investigating the annealing effects on the mechanical, morphological and surface properties of 3D printed PETG/OMMT nanoclay composites Prashanthkumar Hadi, Athul Joseph, Vinyas Mahesh, Vishwas Mahesh, Dineshkumar Harursampath Journal of Thermoplastic Composite Materials, 2026 Fused Filament Fabrication (FFF) is a highly sought-after manufacturing method that builds parts layer by layer using thermoplastic and/or composite filaments. However, it is characterised by weak interlayer adhesion, resulting in low interlaminar strength in printed structures. Recent research suggests that post-processing heat treatments can address this issue by lowering internal thermal stresses and increasing interlayer bonding, thereby improving part properties. This study investigates the effect of annealing heat treatment on a composite consisting of glycol-modified polyethylene terephthalate (PETG) and organically modified montmorillonite nanoclay (OMMT-NC). The annealing temperature was set at 90°C, and the time duration was varied to 60, 120, and 180 minutes. The mechanical, morphological and surface properties of the OMMT-NC reinforced PETG composite were compared with those of pure PETG. Also, annealing effect on the glass transition temperatures was determined by differential scanning calorimetry (DSC). Atomic Force Microscopy (AFM) was used to investigate the change in surface roughness resulting from annealing. The experimental results show that PETG reinforced with 3 wt.% OMMT nanoclay improved the tensile, compression, flexural, and impact strength by 6.9%, 22.9%, 30.3%, and 87.5%, respectively, after annealing. The hardness also increased across all PETG composites by at least 5%, due to improved interlayer adhesion. Morphological studies were conducted to correlate the deformation behaviour and assess the impact of annealing. The findings of this work indicate that PETG/OMMT-NC composites are a potential candidate for structural applications.
Experimental investigation of the in-plane quasi-static mechanical behaviour of additively-manufactured polyethylene terephthalate/organically modified montmorillonite nanoclay composite auxetic structures Vinyas Mahesh, Prasad G Maladkar, Gangu SS Sadaram, Athul Joseph, Vishwas Mahesh, et al. Journal of Thermoplastic Composite Materials, 2023 Apart from the inherent anomalous behaviour under tensile and compressive structures, auxetic structures have shown improved energy absorption characteristics that are of prime interest to various fields of study. This is further exemplified by additive manufacturing (AM) techniques and polymer composites to tailor the shape, geometry and form of these structures. Consequently, this paper aims to characterise the in-plane compressive behaviour and negative Poisson’s ratio (NPR) of the most prominent auxetic structures fabricated additively used polymer nanocomposite materials. The study incorporates the use of glycol-modified polyethylene terephthalate (PETG) and nanocomposites of PETG filled with organically modified montmorillonite (OMMT) nanoclay particles to produce auxetic structures fabricated through fused filament fabrication (FFF). Different structures such as hexagonal re-entrant honeycomb structures, peanut-shaped honeycombs, chiral honeycomb structures and missing rib structures are characterised for their compressive performance through experimental approaches involving mechanical testing and digital image correlation (DIC). Different parameters such as the peak crushing strength, average crushing strength, NPR, specific energy absorption (SEA), and crush force efficiency (CFE) of these structures are evaluated at different strain rates/loading rates for varying concentrations of nanoclay and PETG. It is observed that higher loadings of nanoclay particles lower the compressive strength of the structures. Additionally, the NPR decreases with increasing strain rates and is also influenced by the composition and the resultant stiffness. Moreover, the geometrical parameters of the structure largely influence its strain energy absorption. The results have shown that such material-structure combinations can produce structures of high-performance capabilities suitable for aerospace applications.
Effect of loading rates on the in-plane compressive properties of additively manufactured ABS and PLA-based hexagonal honeycomb structures Athul Joseph, Vishwas Mahesh, Vinyas Mahesh Journal of Thermoplastic Composite Materials, 2023 Honeycomb structures find numerous applications in automotive, aerospace, sports, and other similar engineering fields. Such incorporation is made possible by the excellent crushing resistance and specific energy absorption capabilities. However, manufacturing such structures through conventional processes is highly laborious and expensive. Such a drawback can be largely mitigated by the adoption of additive manufacturing (AM) processes. Consequently, in this study, hexagonal honeycomb structures are subjected to experimental tests to determine their compressive strength under different loading rates. In addition to this, attempts have also been made to evaluate the effect of different materials and the unit cell dimensions on the compressive properties. The test specimens of different wall thicknesses are manufactured by fused deposition modelling (FDM) using PLA and ABS as the base materials. The samples are then subjected to compressive tests using a standard UTM to quantify the effect of the cell geometrical parameters and the loading rate on the overall compressive nature of the structures. The results show that the compression properties are primarily affected by the loading rate, material properties and the cell-wall thickness of the structures. The initial compressive yield stress and plateau stress generally increase up to a given value of loading rate, after which the strength decline. The cell-wall thickness of the structure influences the threshold loading rate. Therefore, this study provides a preliminary understanding of the compressive properties of AM hexagonal honeycomb structures to analyse the prospects for application in real-world engineering applications. It is proposed that such structures find profound applications in structural components of aerospace equipment, automotive parts, sports gear, and other similar areas of interest where high strength and energy absorption are of predominant importance.
Crashworthiness of biocomposites in automotive applications Athul Joseph, Vishwas Mahesh, Vinyas Mahesh, Dineshkumar Harursampath, MAR Loja, et al. Biocomposites for Industrial Applications Construction Biomedical Transportation and Food Packaging, 2023
Spray morphology and droplet characteristics in gas centered swirl coaxial (GCSC) atomizers J Athul 2020
Experimental Characterization of Sprays in a Recessed Gas-Centered Swirl Coaxial Atomizer A Joseph, R Sakthikumar, D Sivakumar Journal of Fluids Engineering 142 (4) , 2020 2020 Citations: 9
Effect of Orifice Recess on the Droplet Size Distribution of Sprays Discharging from Gas-Centered Swirl Coaxial Atomizers A Joseph, P Nandagopalan, TJ Tharakan, D Sivakumar Fluid Mechanics and Fluid Power–Contemporary Research, 1091-1100 , 2017 2017 Citations: 2
Characterization of Sprays Discharging from Gas-Centered Swirl Coaxial (GCSC) Atomizer Using PDI A Joseph, R Sakthikumar, D Sivakumar ILASS-Asia 2016, 18 th Annual Conference on Liquid Atomization and Spray … , 2016 2016
Liquid Sheet Breakup in Recessed Gas-Centered Swirl Coaxial (GCSC) Atomizers A Joseph, R Sakthikumar, D Sivakumar ILASS – Europe 2016, 27th Annual Conference on Liquid Atomization and Spray … , 2016 2016
MOST CITED SCHOLAR PUBLICATIONS
Experimental Characterization of Sprays in a Recessed Gas-Centered Swirl Coaxial Atomizer A Joseph, R Sakthikumar, D Sivakumar Journal of Fluids Engineering 142 (4) , 2020 2020 Citations: 9
Effect of Orifice Recess on the Droplet Size Distribution of Sprays Discharging from Gas-Centered Swirl Coaxial Atomizers A Joseph, P Nandagopalan, TJ Tharakan, D Sivakumar Fluid Mechanics and Fluid Power–Contemporary Research, 1091-1100 , 2017 2017 Citations: 2
Spray morphology and droplet characteristics in gas centered swirl coaxial (GCSC) atomizers J Athul 2020
Characterization of Sprays Discharging from Gas-Centered Swirl Coaxial (GCSC) Atomizer Using PDI A Joseph, R Sakthikumar, D Sivakumar ILASS-Asia 2016, 18 th Annual Conference on Liquid Atomization and Spray … , 2016 2016
Liquid Sheet Breakup in Recessed Gas-Centered Swirl Coaxial (GCSC) Atomizers A Joseph, R Sakthikumar, D Sivakumar ILASS – Europe 2016, 27th Annual Conference on Liquid Atomization and Spray … , 2016 2016
