Faculty Publications
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Item Buckling and free vibrations behaviour through differential quadrature method for foamed composites(Elsevier B.V., 2023) Duryodhana, D.; Waddar, S.; Bonthu, D.; Jeyaraj, P.; Powar, S.; Doddamani, M.The current work focuses on predicting the buckling and free vibration frequencies (fn) of cenosphere reinforced epoxy based syntactic foam beam under varying loads. Critical buckling loads (Ncr) and fn are predicted using the differential quadrature method (DQM). Ncr and fn have been calculated for beams of varying cenosphere volume fractions subjected to axial load under clamped-clamped (CC), clamped-simply (CS), simply-simply (SS), and clamped-free (CF) boundary conditions (BC′s). Upon increasing the cenosphere volume fraction, Ncr and fn of syntactic foam composites increases. These numerical outcomes are compared with the theoretical values evaluated through the Euler-Bernoulli hypothesis and further compared with experimental outcomes. Results are observed to be in precise agreement. The results of the DQM numerical analysis are given out for the different BC′s, aspect ratios, cenosphere volume fractions, and varying loads. It is perceived that depending on the BC′s, the type of axial varying loads and aspect ratios has a substantial effect on the Ncr and fn behaviour of the syntactic foam beams. A comparative study of the obtained results showed that the beam subjected to parabolic load under CC boundary conditions exhibited a higher buckling load. © 2023 The AuthorsItem Influence of subsequent thermomechanical cycles on shape memory behavior of 4D printed PEKK(Elsevier B.V., 2023) Ojha, N.; Kumar, S.; Ramesh, M.R.; Balan, A.S.S.; Doddamani, M.The current study identifies and investigates the shape memory response of poly ether ketone ketone (PEKK) for the first time. 4D printed PEKK are subjected to annealing, crystalline behavior, and shape memory studies under susquent thermomechanical cycles. Scanning electron microscopy (SEM) revealed seamless bonding between the printed layers, confirming the suitability of the chosen printing parameters. Differential scanning calorimetry (DSC) results showed higher Tg (161.20 °C) and Tm (339.03 °C). Shape fixity ratio (Rf) is observed to be lower in the higher cycles (∼10% lower in cycle 8 compared to cycle 1), while the shape recovery ratio (Rr) is noted to be decreasing in each cycle ( 20% decreased in cycle 8 compared to cycle 1) due to reduction in storage modulus. The 4D printed PEKK exhibited excellent shape memory properties as compared to PEEK, making them potential materials in automotive and aerospace applications. © 2023 Elsevier B.V.Item Numerical and experimental stress analysis of spur gears for weight reduction using radial holes(Springer-Verlag Italia s.r.l., 2024) Sutar, S.S.; Kumar, G.C.M.; Doddamani, M.Geometric optimization for the optimal use of material and the weight reduction of gear is possible by removing material from the gear teeth. The current research focuses on the stress analysis of gear with radial holes drilled through the gear tooth to reduce the weight of standard gear. The radial holes from the tip of the gear tooth for different depths are introduced. A standard gear with holes is analyzed using ANSYS, and the magnitude of stresses near the root of the gears for similar loading and boundary conditions are studied. New efforts have been made to study the stress distribution by photoelastic technique to supplement FEA results and confirm the stress distribution of gear with and without radial holes. This process achieves a volume reduction of up to 6.1% compared to an AGMA standard spur gear without affecting much of the stress distribution. These holes may be helpful for adequate lubrication and cooling of gears by fluid circulation. © The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature 2023.