Athul Joseph
@alliance.edu.in
Assistant professor/Aerospace Engineering
Alliance University, Bangalore
EDUCATION
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.
Scopus Publications
Scholar Citations
Scholar h-index
Scopus Publications
Vinyas Mahesh, Prasad G Maladkar, Gangu SS Sadaram, Athul Joseph, Vishwas Mahesh, and Dineshkumar Harursampath
SAGE Publications
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.
Athul Joseph, Vishwas Mahesh, and Vinyas Mahesh
SAGE Publications
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.
Renuka Sahu, Athul Joseph, Vishwas Mahesh, Vinyas Mahesh, and Dineshkumar Harursampath
Elsevier
Renuka Sahu, Athul Joseph, Vishwas Mahesh, Vinyas Mahesh, Sumit Bhowmik, and Dineshkumar Harursampath
Elsevier
Athul Joseph, Vishwas Mahesh, Vinyas Mahesh, Dineshkumar Harursampath, MAR Loja, and Sumit Bhowmik
Elsevier
Athul Joseph
CRC Press
Athul Joseph, Vinyas Mahesh, Vishwas Mahesh, Dineshkumar Harursampath, and Vasu Mallesha
CRC Press
Athul Joseph, Vinyas Mahesh, Vishwas Mahesh, and Dineshkumar Harursampath
CRC Press
Athul Joseph, Vinyas Mahesh, Vishwas Mahesh, and Dineshkumar Harursampath
Elsevier
Athul Joseph, Vinyas Mahesh, and Dineshkumar Harursampath
Springer Science and Business Media LLC
Vinyas Mahesh, Athul S. Joseph, Vishwas Mahesh, and Dineshkumar Harursampath
Wiley
Vinyas Mahesh, Athul S. Joseph, Vishwas Mahesh, Dineshkumar Harursampath, and Chethan VN
Wiley
A. Joseph, R. Sakthikumar, and D. Sivakumar
ASME International
Abstract The characteristics of sprays from a recessed gas-centered swirl coaxial atomizer (RGCSCA) with gas to liquid momentum flux ratio, J of the spray in the range of 2–66 are studied experimentally through the analysis of spray morphologies and droplets characteristics. The process of fully developed spray (spray free from ligaments/droplets clusters and nonspherical droplets) in the atomizer is quantified. In the RGCSCA, the distance from the atomizer exit to the fully developed spray zone decreases with increase in J. Detailed measurements of size (in the range of 6–378 μm) and velocity (in the range of 35–176 m/s) characteristics of spray droplets are carried out using phase Doppler interferometry (PDI) in the fully developed spray. The spray from the RGCSCA is comprised of two distinct spray morphologies: a central dense spray of finer droplets and an outer coarse spray. The mean drop size of the central spray exhibits a decreasing trend with the increase in J whereas that of the outer coarse spray is independent of J. The radial profiles of the mean velocities of sprays at different J are presented. For the sprays with low inertia liquid sheets, the shape of mean axial velocity profiles is Gaussian.
Athul Joseph, P. Nandagopalan, T. John Tharakan, and D. Sivakumar
Springer India