Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
Browse
20 results
Search Results
Item Analysis of light weight natural fiber composites against ballistic impact: A review(KeAi Publishing Communications Ltd., 2023) Doddamani, S.; Kulkarni, S.M.; Joladarashi, S.; Mohan Kumar, M.K.; Gurjar, A.K.The main factors in the ballistic impact mechanism, an incredibly complicated mechanical process, are the target material's thickness, toughness, strength, ductility, density, and projectile parameters. Creating resilient, high-strength, and high-modulus fibers has made it possible to use natural fibers and their composite laminates for various impact-related applications today. Kinetic energy absorption, penetration depth, and residual velocity were the parameters affecting the performance of natural fiber composites used in the armor systems. This review aims to comprehend the several influencing factors that significantly impact the target's ballistic impact performance. In addition to experimental study efforts, many analytical, numerical modeling, and empirical technique-based research approaches have also been considered while analyzing the various components. The paper also examines several factors that determine how well natural fiber composite functions, including internal factors like material composition, characteristics of matrix and reinforcement, the kind and choice of fiber/matrix, failure modes, impact energy absorption, and external factors such as residual velocity, and various projectile nose angles. It also emphasizes the ways to improve composites for high performance and ballistic efficiency, as well as the economic cost analysis of switching out synthetic fibers for natural ones in a ballistic composite. © 2023 The AuthorsItem Effect of addition of TiC nanoparticles on the tensile strength of Al7075-graphene hybrid composites(MIM RESEARCH GROUP, 2023) Lingaraju, L.S.; Channabasappa, M.; Doddamani, S.In the current work, the effect of the addition of titanium carbide and graphene nanoparticles on the tensile strength of the aluminum 7075 matrix composites is investigated. The preparation of the mentioned composites is made using a novel ultrasonic stir casting process. The reinforcements used are 0.25wt% graphene nanoparticles and 0.5wt% to 2.5wt% of titanium carbide nanoparticles. Ultrasonic stir casting techniques are used to enhance the wettability of TiC and graphene nanoparticles. To quantify the microstructure of the prepared composites, SEM and EDS are used. An experimental investigation has been carried out to determine the influence of the addition of TiC and graphene nanoparticles on the tensile strength of the mentioned composite. From the SEM analysis, it is observed that the prepared composites have a uniform distribution of the reinforcements and the EDS analysis confirms the existence of reinforcing elements in the Al7075-TiC/Graphene composites. Experimental results show that the addition of TiC and graphene enhances the hardness and tensile strength. This enhancement is lost with the ductility of the Al7075-TiC/Graphene composites. The fractographic samples of the Al7075- TiC/graphene composites shows cracks in the vicinity of the matrix and reinforcements and also show a brittle fracture. © 2023 MIM Research Group. All rights reserved.Item Structural and modal analysis of crankcase of single cylinder diesel engine(Springer-Verlag Italia s.r.l., 2023) Dhummansure, V.; Doddamani, S.; Jamadar, N.I.; Mohamed Kaleemulla, K.Among the most critical components, crankcase the housing for the crankshaft is used for effective and precise working of the internal combustion engine. The main aim of this work is to analyze the structural and modal parameters of the crankcase of diesel engine of existing and modified model. Solid model of the crankcase is generated using the commercially available software packages, as per the dimensional details of existing crankcase. Static and vibrational analysis of the crankcase is carried out using commercially available software packages for the boundary conditions in accordance with engine specifications and mounting conditions. The modified model of the crankcase is also modeled, analyzed and compared with the existing model of the crankcase. The modified model is prepared for the experimentation using the fast fourier transformer (FFT) analyzer. Simulation results show that the modified model of the crankcase demonstrates the reduced stresses (by 10%) and deformation by (40%) with the existing model also absorb more vibrations. © 2022, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.Item Optimization of process parameters for ballistic impact response of hybrid sandwich composites(Springer-Verlag Italia s.r.l., 2023) Mohan Kumar, T.S.; Joladarashi, S.; Kulkarni, S.M.; Doddamani, S.The low-cost, eco-friendly ballistic impact resistance materials are gaining more importance in defense applications. The present work investigates the findings of ballistic impact behavior of a Jute-Rubber-Jute-Epoxy (Sand)-Jute-Rubber-Jute (JRJ-ES-JRJ) hybrid sandwich composite for different core thicknesses (10, 15, 20 mm) and different filler composition (0, 20, 40%) subjected to impact at 350 mps using different shaped projectiles like flat (F), conical (C), and hemispherical (H) using a numerical and parametric approach. Hybrid JRJE(%S)JRJ sandwich composites is modeled and simulated using commercially available dynamic explicit software, with the projectile as a rigid body and the target as a deformable material. Simulations are performed as per Taguchi's design of experiments approach for the L27 orthogonal array. The results show that filler composition and core thickness are the most critical factors determining ballistic behavior for the proposed hybrid sandwich composite structure. The Hybrid JRJ-ES-JRJ sandwich composites impacted with a conical-shaped projectile absorb the maximum energy, but the composite impacted with a flat-shaped projectile suffers more severe and immediate damage. © 2022, The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.Item Investigation of impact energy absorption of AA6061 and its composites: role of post-aging cooling methods(Gruppo Italiano Frattura, 2023) Krishna Reddy, G.V.; Naveen Kumar, B.K.; Hareesha, G.; Rajesh, A.M.; Doddamani, S.Al6061 and its composites are widely employed in applications requiring high strength and impact resistance. Heat treatment, particularly ageing, is a well-established method for enhancing the mechanical properties of these composites. However, the influence of post-ageing cooling methods on the impact energy absorption capacity of Al6061 and its composites is not well understood. This investigation aims to examine the impact energy absorption of Al6061 and its composites after ageing at 460°C for 2 hours, employing different cooling methods, including furnace cooling, air cooling, and water cooling. The composites were produced using the stir casting technique with varying weight fractions of graphite and SiC particles based on Taguchi's design of experiments. Charpy impact tests were conducted using a specialised testing machine. The results reveal that the impact energy absorption capacity of the composites is influenced by the cooling method used after the ageing treatment. Furnace cooling demonstrated the highest impact energy absorption capacity compared to the other cooling methods, exhibiting a 28% increase relative to the monolithic aluminium alloy. Furthermore, it was observed that the impact energy absorption capacity of the composites did not improve with an increase in the weight fraction of SiC particles, while the addition of graphite negatively impacted the absorption capacity. © 2023, Gruppo Italiano Frattura. All rights reserved.Item Fracture toughness investigations of AA6061-SiC composites: Effect of corrosion parameters(Elsevier Ltd, 2023) Ramesh, R.S.; M.v, S.K.; Begum, Y.; Doddamani, S.; K, M.K.The research gap in this problem lies in the limited understanding of how corrosion parameters, such as reinforcement composition, exposure time, and concentration of the corrosive agent, affect the fracture toughness of AA6061-SiC composites. Investigating these factors can provide valuable insights into the corrosion behaviour of AA6061-SiC composites and help optimise their mechanical properties for specific applications in harsh environments. The study aimed to optimise the parameters and find the best combination of composition, normality, and exposure time that improves fracture toughness. The study's results showed that normality (37%), and exposure time (47%) significantly affected the material's fracture toughness. Fracture toughness tests showed Case 1 had higher fracture toughness (18.35 MPa√m) due to lower normality and shorter exposure time, indicating a less aggressive corrosive environment. In contrast, Case 3 had lower fracture toughness (14.86 MPa√m) due to higher normality and longer exposure time, suggesting increased corrosion severity. In particular, increasing the exposure time and concentration of the corrosive agent decreased the fracture toughness. The composite was exposed to a 3.5% NaCl solution, which caused severe damage and formed a protective oxide layer. However, pitting corrosion occurs and causes decreasing in fracture toughness. © 2023 Elsevier B.V.Item Development of rubber-sand composite for enhanced impact resistance: Implications of vulcanization(Elsevier B.V., 2024) Doddamani, S.; Kulkarni, S.M.; Joladarashi, S.; Gurjar, A.K.; Mohan Kumar, T.S.Developing rubber-sand composites for enhanced impact resistance faced challenges in material selection, optimisation of vulcanisation, interfacial bonding, and understanding underlying mechanisms. This study provides insights into the effect of vulcanisation on the energy absorption of rubber-sand composites and the potential benefits of adding sand particles as reinforcement, sulfur as a vulcanising agent and carbon black as reinforcement filler. Rubber-sand composites are made from the vulcanisation of natural rubber latex and reinforced with sand particles. Taguchi's design of experiments was used to vary the contents of sulfur (2, 3 and 4) and carbon black (30, 40 and 50) parts per hundred rubber (phr) and sand particles (0, 5 and 10 vol%). After vulcanisation, the composite blocks were prepared using the hot compression moulding technique for experimentation. The shore A hardness and low-velocity drop weight tests have been carried out to investigate the Rubber-sand composite's hardness and energy absorption properties, respectively. The results showed that the increment in the sulfur content increases the hardness of the rubber-sand composite. Additionally, sand particles and carbon black improved the composite's shore A hardness and energy absorption. Multiscale modelling techniques effectively simulated the experimental behaviour of the rubber-sand (Ru-San) composite, with a 3 – 11% error, demonstrating its capability to capture the structural response and damage characteristics under projectile impact conditions. The optimised composite has potential applications in industries that require impact resistance, such as the military, automotive and sports industries. © 2024 Karabuk UniversityItem Investigation of mechanical properties of luffa fibre reinforced natural rubber composites: Implications of process parameters(Elsevier Editora Ltda, 2024) Gurjar, A.K.; Kulkarni, S.M.; Joladarashi, S.; Doddamani, S.Natural fiber-reinforced composite materials are highly beneficial due to their excellent strength-to-weight ratio, and the compression molding process is frequently used to prepare natural fiber composites. The primary objective of the present work is to optimize the process parameters of the compression molding method to prepare luffa fiber-reinforced natural rubber composite and investigate the influence of process parameters on mechanical properties. Pre-processing parameters, specifically oven-dry temperature and time, processing parameters such as soaking temperature, time, and compression pressure, and post-processing parameters, such as oven-dry temperature and time, were considered to optimize. Natural rubber in its latex phase is utilized as a matrix material, and luffa fiber is used as reinforcement. The Plackett-Burman screening design technique was employed to identify the impact of different processing parameters on the mechanical properties of the luffa fiber-reinforced natural rubber (LNR) composite, and based on Taguchi's design of experiments, several process parameters were utilized to create L27 orthogonal array and the mentioned composites prepared accordingly. The ASTM standard is followed while testing the composite samples to determine their density, shore A hardness, and tensile strength. The density of the composite is unaffected by the process parameters; however, the shore A hardness of the composite is significantly affected. All the processing parameters most significantly impacted the tensile strength of LNR composites. The optimized process parameters for preparing LNR composite are the pre-oven temperature of 65 °C and time of 150min, the soaking temperature of 75 °C and time of 5min, compression pressure of 1.5 MPa, and the post-oven dry temperature of 55 °C and time of 45min. LNR composite can absorb energy due to its rubber matrix, making it useful for high-impact applications. © 2024 The AuthorsItem Experimental and numerical investigation on low-velocity impact response of sandwich structure with functionally graded core(John Wiley and Sons Inc, 2024) Mohan Kumar, T.S.; Joladarashi, S.; Kulkarni, S.M.; Doddamani, S.The present research investigates optimizing the impact resistance of functionally graded sandwich structures using experimental and numerical approaches. The low-velocity impact (LVI) responses of functionally graded sandwich composite (FGSC) with different configurations with skin material jute/rubber/jute (JRJ) and core material having epoxy and sea sand by volume fraction of sea sand at 0%, 10%, 20%, and 30%. Sandwich structures were impacted with LVI (5.89, 10.92, and 15.18 m/s), with the impactor dropped from heights of 0.5, 1, and 1.5 m with precompressed spring loads. FGSC samples are considered a deformable body, and the impactor is modeled as a rigid body using commercially accessible dynamic explicit software. The burn-out test and weight method were used to test the core's gradience; both methods' results substantially matched, and the variance in gradation could be observed. The proposed sandwich structure characteristics are examined by energy absorption, peak force, energy loss percentage, and coefficient of restitution. Results showed that SC30S provides greater energy absorption and superior damage resistance when tested on LVI. To evaluate the accuracy of experimental findings in predicting the indentation behavior of the sandwich structure, the finite element analysis was used to compare with the experimental results. According to the examination of these proposed FGSC overall performance, they could potentially be employed as sacrificial materials for LVI applications like claddings to shield major structural components. The systematic approach used in this work serves as a standard for choosing and using FGSC effectively for LVI applications. Highlights: Low-velocity impact behavior of sandwich structures was investigated. Combining flexible skin and epoxy core enhances energy absorption. Based on impact energy levels, impact damage areas were determined. Examined sandwich structure advantages in structural and aerospace uses. In terms of time and cost, the numerical analysis method would be useful. © 2023 Society of Plastics Engineers.Item Investigation on the Hardness of Al6061 Alloys: Implications of Seawater Corrosion(Springer, 2024) Begum, Y.; Doddamani, S.This study aims to investigate the impact of seawater corrosion on the hardness of Al-Mg-Si alloys, providing insights into the mechanical alterations induced by exposure to corrosive marine environments. Al-Mg-Si alloys are widely used in marine environments because of their high strength-to-weight ratio and excellent corrosion resistance. However, exposure to seawater can lead to corrosion, which can alter their mechanical properties, including hardness. In this study, Al6061 alloy specimens were exposed to seawater for different periods (3–30 days), and their hardness was measured using Vickers hardness testing. The corrosion rate was determined by weight loss analysis. The results showed that the corrosion rate of Al6061 alloys increased with increased exposure time in seawater, up to 20%. The hardness versus corrosion rate plot analysis indicates an inverse relationship, with scatter points aligning well with a linear regression model. The Vickers' hardness of the samples decreased as the corrosion rate increased. This hardness decline in Al6061 alloys under escalating corrosion rates is attributed to material loss, heightened porosity, and microstructural transformations arising from corrosion product formation. Comprehensive corrosion micrographs unveiled advanced corrosion stages, marked by dynamic pit and crack expansion, oxide layer degradation, pit coalescence, and emergence of distinct corrosion patterns. © The Minerals, Metals & Materials Society 2024.