Abstract: FRP patches are adhesive bonded to damaged metallic hulls in an effort to repair and rehabilitate damaged/cracked metallic naval structures. Inspite of the existing technology, the performance of these patches are not reliable under standard marine conditions which includes salt water and cold weather exposure. There have been reports of delamination of these adhesive bonded patches from the metallic surface. It appears that there is a lack of fundamental knowledge of bonding between the FRP patches and metallic plates in literature which will be addressed in this study through coordinated experimental investigation and numerical simulation at the molecular/atomistic level. A probabilistic model will also be developed to assess the failure probability of the patches given numerous input parameters associated with loading, material and geometric features in addition to data obtained at the molecular level via simulations. It is anticipated that the coordinated experimental-molecular-simulation based study will also help in future development of proper constitutive models for bonds at the continuum level.
Funded: Office of Naval Research [ONR] (2022-2025)
Relevant Publications:
- Prasad, D., Mitra, N. (2025). “Catalytic effects of water solvated metal cations in epoxy-amine curing through hydrogen bonds and metal-ligand interactions.” Journal of Physical Chemistry B. 129:3464-3481. Link
- Prasad, D., Mitra, N. (2025). “Adsorption mechanisms in polymer-ceramic interfaces: DFT investigations.” Journal of Physical Chemistry C. 129:4597-4613. Link
- Prasad, D., Mitra, N. (2024). “Non-covalent interactions define global properties of HTPB isomers.” Journal of Physical Chemistry B. 128(34): 8238-8245. Link
Abstract: As a shock wave passes through a medium, it can alter the physical characteristic of the medium. Since shock waves are quite ubiquitous in air and water medium for numerous defense and hypersonic related applications, the changes in the medium needs to be accounted for and well characterized.
Funded: Office of Naval Research Global [ONR Global] (2018-2021) 
Relevant Publications:
- Rawat, S., Mitra, N. (2023). “Atomistic insight into the shock-induced bubble collapse in water” Physics of Fluids,35(9):097114. Link
- Prasad, D., Mitra, N. (2022). “High temperature-high pressure plastic phase of ice at the boundary of liquid water and ice VII.” Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 478(2260): 20210958. Link
- Pal, S., Mitra, N. (2021). “Shock wave propagation through air: A reactive molecular dynamics study.” Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 477(2247): 20200676. Link
Abstract: Structural health monitoring (SHM) in Sandwich composites is difficult since none of the conventional techniques (such as Eddy currents, Ultrasound C-scan, Acoustic emission) work as the impulse generated from source are absorbed by the foam layers. In an effort to develop alternative measures, embedded fiber optics can be utilized to provide a real time determination of the health of the structure in operation.
Funded: Indian Space Research Organization [ISRO] (2014-2017) 
Relevant Publications:
- Mitra, N., Patra A., Singh, S.P., Mondal S., Datta, P.K., Varshney, S.K. (2020). “Interfacial delamination in glass-fiber/polymer-foam-core sandwich composites using Singlemode-multimode-singlemode optical fiber sensors: Identification based on experimental investigation.” Journal of Sandwich Structures and Materials. 22(1). 40-54. Link
- Mitra, N., Patra A., Mondal, S., and Datta, P.K. (2019). “Interfacial delamination crack profile estimation in polymer foam-cored sandwich composites.” Engineering Structures, 189, 635-643. Link
Abstract: Sandwich composite panels are utilized by several naval defense organizations throughout the world (e.g. mine counter measure vehicles [MCMV]). However, the physics of shock wave propagation, reflection through water as well as energy absorption by sandwich panels are not well understood in comparison to significant improvements with respect understanding of shock wave propagation and reflection in air due to aerospace and hypersonics community. The study will investigate explosion induced non-contact shock wave propagation and reflection underwater as well as its effect on sandwich composite panels used in submarines and surface naval ships.
Funded: Naval Research Board, India [NRB] (2011-2015) 
Relevant Publications:
- Ghoshal, R., and Mitra, N. (2020). “Underwater Oblique shock wave reflection from submerged hydraulic structures.” Ocean Engineering, 209, 107324.
- Ghoshal, R., and Mitra, N. (2018). “Underwater Oblique shock wave reflection.” Physical Review Fluids. 3, 013403.
- Neogi, A., and Mitra, N. (2016). “Shock induced Phase transition in water: Molecular Dynamic investigation.” Physics of Fluids. 28, 027104
- Ghoshal, R., and Mitra, N. (2016). “Underwater explosion induced shock loading of structures: Influence of water depth, salinity and temperature.” Ocean Engineering. 126, 22-28.
- Ghoshal, R., and Mitra, N. (2014). “On core compressibility of sandwich composite panels subjected to intense underwater shock loads.” Journal of Applied Physics, 115(2), 024905.
- Ghoshal, R. Mitra, N. (2012). “Non-contact near field underwater explosion induced shock wave loading of submerged rigid structures: nonlinear compressibility effects in fluid structure interaction.” Journal of Applied Physics, 112(2), 024911.