Browsing by Author "Chakraborty, Sadananda"

Filter results by typing the first few letters
Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    A Study in Friction Stir Welding on Marine Grade Dissimilar Metals
    (Indian Maritime University, Kolkata Campus, 2024) C, Harshit; Chakraborty, Sadananda
    Friction Stir Welding is an advanced technique for joining dissimilar materials, mitigating traditional welding issues like solidification cracking and distortion. This study explores friction stir welding for marine-grade Aluminium Alloy 6063-T4 (AL6063-T4) and Magnesium Alloy AZ31B (MG AZ31B), highlighting their lightweight and corrosion-resistant properties suitable for marine environments. Chapter 1 provides a comprehensive background, goals, and benefits of the study. It includes detailed analyses of relevant journal articles and modifications of general articles pertinent to this project. To improve both the weld quality and the efficiency of the friction stir welding process. Chapter 2 goes into detail about Tool geometry which is critically examined to enhance weld quality and friction stir welding efficiency. Steady-state temperature analysis identifies the optimal tool shape using "SolidWorks" for superior mechanical and thermal performance. The tool assembly includes a high-speed steel (HSS) drill bit and an H13 tool steel shoulder. In Chapter 3 a custom vertical milling machine welds two alloy plates, modelled independently in ANSYS for thermal analysis. The study uses SOLID70 elements for three dimensional thermal analysis, with precise boundary conditions to ensure accurate predictions. A tetrahedral mesh captures high-temperature gradients and stress concentrations, providing insights into deformation, stresses, temperature, and welding properties. In Chapter 4, AL 6063-T4 and MG AZ31B alloys are joined using friction stir welding, with specific surface preparation and butt joint configurations. Mechanical testing includes Vickers microhardness and tensile tests, revealing variations in joint hardness and intricate stress-strain behaviours. Failure analysis identifies TMAZ as the primary failure site, emphasizing its diverse texture structures and fracture initiation. Chapter 5 focuses on optimizing hardness and tensile strength through experimental and Computational Fluid Dynamics (CFD) analysis. ANOVA assesses the impact of rotational and travel speeds on tensile strength, finding rotational speed significantly influences tensile strength. Verification runs confirm the effectiveness of optimized parameters, with minor discrepancies suggesting areas for CFD model improvement. Lastly, friction stirs welding successfully welds 6063 T4 and AZ31B alloys at 430–490°C, enhancing microhardness and joint integrity. While joint tensile strength is lower than base materials, optimization at 1120 rpm and 63 mm/min improves yield strength. Future research should explore microstructural analysis, material innovation, application-specific studies, environmental impact, and standardization, underscoring friction stir welding's potential across various sectors.
  • No Thumbnail Available
    Item
    CFD analysis of marine propeller using duct and testing thrust performance over various duct configurations
    (Indian Maritime University, Kolkata Campus, 2022-11) Chakraborty, Kartik; Chakraborty, Sadananda
  • No Thumbnail Available
    Item
    Evaluation of response characteristics using sensitivity analysis and TLBO technique of powder mixed wire EDM of Ti6Al4V alloy
    (Elsevier, 2023-11-29) Chakraborty, Sadananda
    The development of Powder Mixed Wire Electric Discharge Machining (PMWEDM) aims to enhance both precise dimension and surface quality, making it a more efficient method for the cost-effective production of precise dies and tools compared to conventional Wire Electric Discharge Machining (WEDM. This approach effectively eliminates the need for secondary operations. The present study is focused on the parametric influence of surfactant with powder mixed WEDM process parameters during die corner cutting on Ti6Al4V material in the presence of surfactant and powder with dielectric. A sensitivity analysis was conducted to determine the significant influence of machining parameters and powder properties in conjunction with the dielectric. To empirically explore these variables, a central composite full factorial design based on response surface methodology was utilized. The design involved varying the pulse on-time (Ton) within the range of 30–90 µs, pulse off-time (Toff) within 3–11 µs, gap voltage (GV) within 40–80 V, and powder concentration (PC) within 2–10 g/L. The mathematical model was developed to predict the responses such as corner inaccuracy (CI) and surface roughness (SR) using RSM. The results conclude that the sensitiveness of powder concentration is highest. Apart from this, positive sensitiveness towards surface roughness is determined for three inputs: pulse on time, pulse off time, and powder concentration. In comparison, powder concentration shows positive sensitiveness towards corner inaccuracy. An artificial intelligence technique namely, Teaching learning-based optimization (TLBO) algorithm has been used to determine the best output. The minimum output for both responses, i.e. corner inaccuracy of 12982.67 µm2 and surface roughness of 1.199 µm, was obtained using TLBO technique. Further improvement for surface finish and corner accuracy in addition powder (3 g/L) with dielectric in WEDM process is found to be a value of 50.77% and 23.01%, respectively, compared with conventional WEDM process. SEM was employed to observe and analyze the topographical changes that occurred during powder mixed and without powder mixed in WEDM process.
  • No Thumbnail Available
    Item
    Optimizing ship resistance by modifying hull vane geometry using CFD simulation
    (2023-07) Ubhare, Rajat C.; Chakraborty, Sadananda
    This study focuses on optimizing ship resistance by modifying the geometry of a Hull vane using Computational Fluid Dynamics (CFD) simulations. The resistance reduction potential of various Hull vane designs is investigated by comparing the results obtained from the simulations. The study employs CFD techniques to analyse different Hull vane geometries flow characteristics and resistance. Parameters such as maximum camber and thickness are systematically varied to determine their influence on ship resistance. The simulation results demonstrate that specific modifications to the Hull vane geometry can significantly reduce ship resistance, leading to improved fuel efficiency and speed performance. The findings highlight the importance of considering geometric parameters in the design of Hull vanes for minimizing resistance and optimizing ship performance. The presented results offer valuable insights into the potential benefits of using CFD simulations to optimize ship resistance through Hull vane geometry modifications, providing guidance for future design and optimization studies in the maritime industry. In this work, the effect of changing the geometry of the Hull vane on ship resistance will be investigated using CFD software. This study will explore how modifications to the Hull vane geometry could further enhance this device's resistance-reducing capabilities and contribute to improved ship performance and efficiency. Validation is conducted as well and presented in the section below to authenticate the current work.