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Damage assessment of composite structures using Particle Swarm Optimization
Jebieshia, T.R.,Maiti, D.K.,Maity, D. The Society for Aerospace System Engineering 2015 International Journal of Aerospace System Engineer Vol.2 No.2
Composite materials are highly sensitive to the presence of manufacturing and service-related defects that can reach a critical size during service condition and thereby may affect the safety of the structure. When the structure undergoes some kind of damage, its stiffness reduces, in turn the dynamic responses change. In order to avoid safety issues early detection of damage is necessary. The knowledge of the vibration behavior of a structure is necessary and can be used to determine the existence as well as the location and the extent of damage.
Frequency-Based Damage Assessment of Composite Members Using Unified Particle Swarm Optimization
T. R. Jebieshia,D. K. Maiti,D. Maity 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.1
A numerical procedure is presented to detect and quantify damages in laminated composite beam and plate-like structures using unified particle swarm optimization (UPSO) technique. The presence of damage in any structure alters its integrity and performance (causes reduction in stiffness and strength) and thus changes the vibration response parameters such as frequency, mode shapes, damping ratio, and frequency response functions (FRFs). These changes in structural response parameters can be used for the identification of flaws in composite structures with the help of an optimization technique. For the present study, natural frequency is used as the diagnostic parameter and UPSO has been used as the optimization technique. An in-house Matlab code has been developed using finite element analysis (FEA) and has been used to extract the vibration responses of undamaged and damaged composite structures. Since composite materials are anisotropic in nature, effect of anisotropic damage on vibration characteristics of damaged composite structures is also presented. It is observed that the anisotropic damage exhibits strong orthogonality and in general, the occurrence of damage changes the vibration characteristics of the structure. It is also observed that as the damage intensity and damage area increase, there is considerable reduction occurring in the natural frequencies. The efficacy of the proposed methodology to identify damages is demonstrated using some numerically simulated composite beam and plate structures with single and multiple damages.
Study on Heat Transfer Characteristics in the Channel Flow with Rectangular Winglet Pair
Hemant Naik,T R Jebieshia,Shaligram Tiwari,Heuy Dong Kim 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
Longitudinal vortices generated by winglet type vortex generators play an important role in improvement of thermal performance of heat exchangers. Heat transfer may be enhanced by placing an appropriate configuration of winglet pair. In present study, three-dimensional numerical investigations have been carried out for flow through a channel with rectangular winglet pair (RWP) mounted on its bottom wall. Effect of angle of attack of RWP on flow and heat transfer characteristics has been investigated for a fixed value of flow Reynolds number. Flow and temperature field characteristics are presented using streamlines and temperature contours near the plate surface. Enhancement in heat transfer has been examined by using Nusselt number. Secondary flows generated by winglets are analyzed with the help of secondary flow intensity, which also helps in the estimation of heat transfer enhancement.