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Aircraft goes through various high-speed hindrances like bird attacks, etc. Kevlar is increasingly used in the aviation industry to overcome such hindrances. Kevlar, an organic fibre from the family of aromatic polyamides consists of Kevlar 29, Kevlar 129, Kevlar 49 and Kevlar 149. This paper focuses on the use of Kevlar 29 and Kevlar 129 due to its low stiffness in comparison with Kevlar 49 and Kevlar 149. When pure Kevlar 29 and Kevlar 129 with 20 layers each are impacted with a 9g bullet at 900m/s velocity, the bullet perforates the laminate completely. Hence, the Kevlar layers are reinforced with graphene nanoplates. The bullet impact simulation of the ‘single-layer Kevlar 29 reinforced with single-layer graphene nanosheet’ (K29G), ‘single layer Kevlar 129 reinforced with single-layer graphene nanosheet’ (K129G), ‘double layer Kevlar 29 reinforced with double-layer graphene nanosheets’ (KK29GG) and ‘double layer Kevlar 129 reinforced with double-layer graphene nanosheets’ (KK129GG) is carried out using LS-DYNA. Maximum principal stress, effective stress, absorbed energy and displacement of the composite laminates (K29G, K129G, KK29GG and KK129GG) are used to compare the performance of these four laminates in the targeted applications. Due to its higher maximum principal stress, effective stress and lower displacement, the composite laminate K29G proves to be the apt laminate for its usage in aircrafts.

The purpose of this study is to improve the cooling of brake disc by modifying the wheel rim by fitting it with an axial ventilator. The orientation angle of these blades in axial ventilator is varied between 0 and 10. The numerical investigation is carried out using commercial CFD code ANSYS Fluent. The pressure difference induced in 5 model is maximum leading to a better air flow through the wheel rim resulting with enhanced cooling of the brake disc. The 5 model reduced the brake disc temperature from 450C to 207.84C which is nearly 54%. The surface heat transfer coefficient and Nusselt number of 5 model is found to be maximum. The resulting improvement in heat dissipation enhances the performance and hence the lifetime of the brake disc. Therefore, the wheel rim with axial ventilator 5 model is found to the suitable configuration so as to achieve enhanced convective cooling of brake disc.

Because of increase in threat from militant groups and during war exposure to blast wave from improvised explosive devices, Traumatic Brain Injury (TBI), a signature injury is on rise worldwide. During blast, the biological system is exposed to a sudden blast over pressure which is several times higher than the ambient pressure causing the damage in the brain. The severity of TBI due to air blast may vary from brief change in mental status or consciousness (termed as mild) to extended period of unconsciousness or memory loss after injuries (termed as severe). The blast wave induced impact on head propagates as shock wave with the broad spectrum of frequencies and stress concentrations in the brain. The primary blast TBI is directly induced by pressure differentials across the skull/fluid/soft tissue interfaces and is further reinforced by the reflected stress waves within the cranial cavity, leading to stress concentrations in certain regions of the brain. In this paper, an attempt has been made to study the behaviour of a human brain model subjected to blast wave based on finite element model using LSDYNA code. The parts of a typical human head such as skull, scalp, CSF, brain are modelled using finite element with properties assumed based on available literature. The model is subjected to blast from frontal lobe, occipital lobe, temporal lobe of the brain. The interaction of the blast wave with the head and subsequent transformation of various forms of shock energy internally have been demonstrated in the human head model. The brain internal pressure levels and the shear stress distribution in the various lobes of the brain such as frontal, parietal, temporal and occipital are determined and presented.

Aircraft undergoes various low-velocity impacts such as bird strike, runway debris, foreign tools drop, etc. on its structure. Kevlar is widely used in several components and structure of the aircraft as Kevlar is an organic fiber from an aromatic polyamide family. Carbon fiber has advantages like high stiffness and properties like that of kevlar. The present study focuses on the analysis of low-velocity impact properties of kevlar 149-carbon fiber reinforced polymer matrix composite material. In this analysis, kevlar 149-carbon fiber, pure kevlar 149 by 10 layers of laminate and pure carbon fiber by 10 layers of laminate are impacted by ball material with a mass of 8g at velocity of 9m/s. The ball impact on the laminate is simulated using LS-DYNA. The max. principal stress, absorbed energy, velocity and displacement of K149C, CK149, KK149CC, CCKK149, KK149 and CC are obtained and compared with all the six composite laminates. The composite laminate, K149C, proves to be the best laminate for aircrafts as it possesses a higher max. principal stress and lower displacement.

The focus of this study is to improve the material properties like Poisson's ratio and flexural strength of a sandwich plate by adding carbon nanotubes. A comparative analysis is carried out between sandwich plate with and without addition of carbon nanotubes. Nastran / Patron are the main tools used for this analysis. The experimental work focuses on the behaviour of the sandwich plate while applying tensile and compressive loads. The reduction of displacement in orthogonal sides under compressive stress and tensile stress are observed for carbon nanotubes enriched sandwich plate. This is due to increased face sheet relative difference of lateral strain with longitudinal strain. It is also observed that the mechanical properties of carbon nanotubes enriched sandwich plate are improved in comparison to sandwich plate without carbon nanotubes. It is concluded that the Poisson's ratio for the sandwich panel enriched with carbon nanotubes is advantageous than sandwich panel without carbon nanotubes.

The focus of this study is to improve the material properties like Poisson's ratio and flexural strength of a sandwich plate by adding carbon nanotubes. A comparative analysis is carried out between sandwich plate with and without addition of carbon nanotubes. Nastran / Patran are the main tools used for this analysis. The experimental work focuses on the behaviour of the sandwich plate while applying tensile and compressive loads. The reduction of displacement in orthogonal sides under compressive stress and tensile stress are observed for carbon nanotubes enriched sandwich plate. This is due to increased face sheet relative difference of lateral strain with longitudinal strain. It is also observed that the mechanical properties of carbon nanotubes enriched sandwich plate are enhanced in comparison to sandwich plate without carbon nanotubes. It is found that, for feasible applications, the sandwich plate enhanced with carbon nanotubes, possess greater face sheet relative difference of lateral strain with longitudinal strain. It is concluded that the Poisson’s ratio for the sandwich panel enriched with carbon nanotubes is advantageous than sandwich panel without carbon nanotubes.