Faculty Publications
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Item Hydroelastic analysis of articulated floating elastic plate based on Timoshenko–Mindlin plate theory(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2018) Praveen, P.; Karmakar, D.; Guedes Soares, C.G.The wave interaction with articulated floating elastic plate is investigated considering the Timoshenko–Mindlin thick plate theory for both finite and shallow water depths. The elastic plates are modelled as finite flexible floating structure interconnected with vertical linear/rotational spring stiffness. The eigenfunction expansion method along with the orthogonal mode-coupling relation is used to analyse the hydrodynamic behaviour of the interconnected structure. The study is performed for different articulated edge conditions for varying plate thickness and water depths to understand the behaviour of articulation under the action of an ocean wave. The hydroelastic response of the interconnected floating elastic plate with different connector stiffness is observed to compare well with the result available in the literature. The present study provides an insight into the effect of articulated joints with varying spring stiffness for the suitable design of the structure. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.Item Wave Interaction With Floating Elastic Plate Based on the Timoshenko-Mindlin Plate Theory(American Society of Mechanical Engineers (ASME) infocentral@asme.org, 2019) Praveen, K.M.; Karmakar, D.; Guedes Soares, C.In the present study, the wave interaction with the very large floating structures (VLFSs) is analyzed considering the small amplitude wave theory. The VLFS is modeled as a 2D floating elastic plate with infinite width based on Timoshenko-Mindlin plate theory. The eigenfunction expansion method along with mode-coupling relation is used to analyze the hydroelastic behavior of VLFSs in finite water depth. The contour plots for the plate covered dispersion relation are presented to illustrate the complexity in the roots of the dispersion relation. The wave scattering behavior in the form of reflection and transmission coefficients are studied in detail. The hydroelastic performance of the elastic plate interacting with the ocean wave is analyzed for deflection, strain, bending moment, and shear force along the elastic plate. Further, the study is extended for shallow water approximation, and the results are compared for both Timoshenko-Mindlin plate theory and Kirchhoff's plate theory. The significance and importance of rotary inertia and shear deformation in analyzing the hydroelastic characteristics of VLFSs are presented. The study will be helpful for scientists and engineers in the design and analysis of the VLFSs. © 2019 by ASME.Item Surface gravity wave scattering by multiple energy absorbing structures of variable horizontal porosity(Taylor and Francis Ltd., 2020) Venkateswarlu, V.; Praveen, P.; Karmakar, D.The oblique wave scattering by fully-extended two-layered, three-layered and submerged two-layered porous structures occupying finite width is reported using an analytical model based on the eigenfunction expansion method. The fully extended two-layered structure is composed of two porosities and friction factors in the surface porous layer and the bottom porous layer. In addition, the three-layered energy-absorbing structure is composed of two-porous layers along with the bottom rigid layer to replace the natural seabed variation. Further, the study is extended for multiple energy-absorbing structures to report the impact of free spacing available between the two subsequent structures on fluid resonance. The two-layered porous structure dispersion relation is derived and solved using step approach and Newton-Raphson method. The derived analytical results are validated with the published results of notable authors. The effect of the surface and bottom layers porosity, friction factor, free spacing, structural width, number of structures, and angle of contact on the wave scattering is reported. Finally, the comparative study between the single and multiple energy absorbing structures of multiple horizontal layers is discussed. Further, the significance of the critical angle of contact and fluid resonance for better wave blocking is presented precisely, which is essential for the coastal engineers to design offshore structures. © 2020 Japan Society of Civil Engineers.Item Hydroelastic response of floating elastic plate in the presence of vertical porous barriers(Taylor and Francis Ltd., 2022) Praveen, K.M.; Venkateswarlu, V.; Karmakar, D.The attenuation of the incident wave interacting with a very large floating structure (VLFS) in the presence of vertical barriers is analysed considering small amplitude wave theory. The VLFS is considered to be articulated and is modelled based on Timoshenko-Mindlin plate theory. The eigenfunction expansion method along with the orthogonal mode-coupling relation is employed for the case of finite water depth. The numerical study is performed to analyse the wave reflection, transmission and dissipation characteristics due to the articulated floating plate for the case of bottom standing and surface piercing vertical porous barriers. The hydroelastic behaviour in terms of deflection and strain for an articulated floating thick elastic plate in the presence of porous barriers is analysed. The study reveals that the magnitude of wave attenuation is enhanced due to the presence of vertical porous barriers and also provides an understanding in mitigating the structural response. © 2020 Informa UK Limited, trading as Taylor & Francis Group.Item Dissipation of Gravity Waves Due to Submerged Porous Plate Coupled With Porous Structures(American Society of Mechanical Engineers (ASME), 2023) Krishna, K.R.A.; Abdulla, K.; Karmakar, D.The present study focuses on wave trapping due to the submerged horizontal porous plate combined with the bottom-standing porous structure and surface-piercing porous structure. The submerged plate thickness is considered to be negligible as compared to the incident wavelength and water depth, and the porous structure is considered to be of finite width. The study is performed based on the eigenfunction expansion method, and the wave interaction with the combined structure is investigated using the small amplitude wave theory. The orthogonal mode-coupling relation is used to analyze the wave interaction with the combined structure. The reflection, transmission, and dissipation coefficients along with wave force on the porous structure are investigated to analyze the hydrodynamic performance of the composite porous breakwater system. Further, the effect of porosity of submerged plate and structure, submergence depth of plate and structure, angle of incidence, and the submerged plate length are investigated to analyze the effective wave dissipation by the composite breakwater. In addition, the comparative study of the numerical method is performed with the results available in the literature. The study noted that the wave damping due to the submerged porous plate backed by surface-piercing porous structure is more as compared to the submerged porous plate backed by the bottom-standing porous structure. The study performed will be helpful to scientists and engineers in the design of suitable composite breakwater systems and also assists in selecting the best structural configuration for attenuation of wave height and to protect the offshore facility from high waves in the coastal region. © 2023 American Society of Mechanical Engineers (ASME). All rights reserved.Item Hydrodynamic performance of H-shaped floating breakwater in the presence of a partially reflecting seawall(Taylor and Francis Ltd., 2025) Panda, A.; Muduli, R.; Karmakar, D.; Rao, M.The present study examines the hydrodynamic interaction of surface gravity waves with freely floating H-shaped porous structure situated close to a partially reflecting seawall and without seawall using Multi-Domain Boundary Element Method (MDBEM). The study is performed to examine the performance of the H-shaped floating breakwater for sway, heave, and roll motion, as well as the effects of a seawall on the hydrodynamic parameters associated with the floating body. The horizontal wave force, added mass, radiation damping coefficients, and the horizontal, vertical, and moment acting on the floating structure are analysed under different structural configurations. The numerical model developed using MDBEM approach is validated using the results available in the literature. The primary findings demonstrate that reducing the structural moments and added mass and wave force coefficients, and constructing a seawall adjacent to the breakwater, greatly enhances performance in deep water. The reflection coefficient by the seawall greatly impact damping in shallow water depth but have minimal effect in deep water region, indicating that water depth significantly impacts the wave transformation. The present study provides important insights for developing marine infrastructure in various coastal and offshore environments by demonstrating the potential for customised engineering solutions to reduce wave impacts successfully. © 2025 Informa UK Limited, trading as Taylor & Francis Group.Item Influence of seabed topography on hydroelastic behavior of VLFS integrated with porous breakwater(Elsevier Ltd, 2025) Hemanth, S.; Karmakar, D.The present study investigates the effect of seabed topography on the hydroelastic behaviour of a Very Large Floating Structure (VLFS) integrated with porous floating breakwaters for inclined, irregular, stepped and irregular stepped seabed conditions. The real-world marine environments feature complex topographies that significantly influence wave-structure interactions. The integrated system combines a flexible VLFS with porous floating breakwaters designed to attenuate wave energy and mitigate structural responses. A coupled Multi-Domain Boundary Element Method (MDBEM) for fluid dynamics and the Finite Difference Method (FDM) for structural analysis is employed for the computation, allowing for accurate modelling of wave-structure-seabed interactions. The numerical model developed for the MDBEM-FDM approach is validated against established benchmark results available in the literature. The key parameters, such as seabed slope, seabed irregularity, breakwater porosity, and placement, are analysed to evaluate their impact on hydrodynamic forces, bending moments, and strain distributions. The numerical results indicate that irregular seabed can amplify localized bending stresses by up to 30 % compared to flat beds, while inclined seabed alters wave reflection patterns, intensifying asymmetric loads. However, porous breakwaters effectively reduce transmitted wave energy by 40–50 %, suppressing adverse hydroelastic responses. The study emphasizes the importance of considering seabed topography while designing VLFSs integrated breakwater. The presence of the breakwater helps in the reduction of the stresses brought on by uneven seabed conditions by strategically placing them and optimizing their porosity. The findings from the present study can contribute to the development of resilient VLFS systems in real-world marine environments, ensuring structural integrity under varying seabed conditions. © 2025 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.