Faculty Publications
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Item Multi-objective Optimization of FSW Process Variables of Aluminium Matrix Composites Using Taguchi-Based Grey Relational Analysis(Springer Nature, 2019) Prabhu B, S.R.B.; Shettigar, A.K.; Herbert, M.A.; Rao, S.S.Successful joining of aluminium alloys using friction stir welding (FSW) opens a new window research in extending this technique to join aluminium matrix composites (AMCs). Current research is focused on optimization of process variables for multiple responses simultaneously. Experiments were performed using tool pin profile, rotational speed (RS) and welding speed (WS) as ideal process variables for multi-objective optimization in FSW of AMCs. Tensile strength, macro-hardness and elongation are considered as multi-response behaviour. Grey relational grade for the chosen multiple responses are obtained using grey analysis. Analysis of variance was utilized to understand the influence of process variables on the grey relational grade. Analysis reveals that RS and WS were the most influencing process variables on the output responses. Confirmation experiments were performed at optimized process variables to validate the present study. Predicted values were in good agreement with the experimental results. © 2019, Springer Nature Singapore Pte Ltd.Item Influence of Process Variables on the Ultimate Tensile Strength of Friction Stir Welded AA6061 Matrix Composite(Springer Nature, 2021) Shettigar, A.; Prabhu B, S.R.; Herbert, M.A.; Rao, S.S.The present study is focused on the application of the friction stir welding process (FSW) to weld aluminium matrix composites (AMCs). Joints are formed by varying FSW process variables such as tool revolving speed (TRS), tool traverse speed (TTS) and the tool pin geometry (TPG). Influence of these parameters on the ultimate tensile strength (UTS) of the joints is investigated. Process variable optimization is done using Taguchi L18 orthogonal array design. Optimum process variables are determined and confirmed by confirmation tests based on the analysis of variance. © 2021, Springer Nature Singapore Pte Ltd.Item Mechanical Properties and Microstructural Characteristics of Friction Stir Welded Aluminium Matrix Composite(Springer Nature, 2021) Subramanya, B.; Shettigar, A.; Herbert, M.A.; Rao, S.S.Nowadays, friction stir welding process appears a promising technique to weld difficult materials by conventional welding techniques. Present study aims to analyse the significance of process variables on the mechanical behaviour of aluminium matrix composite joined by friction stir welding (FSW) technique. FSW is carried out at different welding conditions using conventional threaded cylindrical tool (TC). Microstructural study indicates several tiny reinforced particles are uniformly distributed in the nugget region. Recrystallization and grin refinement are observed in the weld area. Nugget region exhibits higher hardness compared to the base material. Joint efficiency of up to 89% is obtained for the FS-welded composite. The fracture surface reveals that the matrix undergoes a ductile fracture whereas reinforced particles exhibit brittle fracture. © 2021, Springer Nature Singapore Pte Ltd.Item An Industry 4.0 Approach: Data Acquisition and Machine Monitoring for Welding Machines(Springer Nature, 2024) Narendra Reddy, T.N.; Ponnappa, N.P.; Prasad, P.; Vinod, P.; Herbert, M.A.; Rao, S.S.The research introduces an innovative application of Industry 4.0 principles in welding by employing IIoTbased performance monitoring equipment. One the important aspect of Industry 4.0 adaption is understanding the requirement from the customer and develop/ provide the acceptable solution to them is crucial. An attempt has been made to develop a solution which can be used for any kind of welding machines including legacy welding machines. The developed solution delivers real-time updates on shop floor welding processes with the help of Operational Technology (OT) and Information technology (IT) with the help of hall effect sensors and voltage transducers by connecting them to the Programmable logic controller (PLC). Additionally, it facilitates real-time feedback, alerts, and report generation. The study comprehensively assesses the effectiveness and production capacity of an industrial welding system, presenting a detailed design overview and practical demonstration. Potential enhancements, such as integrating machine learning, emphasizing remote monitoring, evaluating energy efficiency, addressing cybersecurity, and assessing scalability, are explored. The research includes a cost–benefit analysis for the shopfloor and provides insights into the real-world effectiveness of IIoT-based welding performance monitoring in industrial contexts. The developed solution has been tested, validated, and deployed in one of the welding industries, and it has helped in real-time monitoring, scheduling the work and data analytics. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Item Correlational Study of Ultimate Tensile Stress and Hardness of Friction Stir-Welded Al–Ce–Si–Mg Aluminum Alloys(Springer Nature, 2024) D’Souza, A.D.; Herbert, M.A.; Rao, S.S.In this research article, an analysis of correlation between mechanical properties of aluminum alloy such as ultimate tensile stress and Vickers hardness is carried out. Research analysis shows that hardness and UTS have a direct relationship. Tool rotation speed also directly impacts hardness and UTS values by controlling the amount of heat generated and hence extent of plasticization and grain refinement in the region of the weld. According to the research results, the plane surfaces of the square profiled pin of the tool aid in introducing a pulsing effect, which contributes to improved strength of weld connection. When compared to other tool profiles, a higher dynamic-to-static ratio attained with the triangular profiled pin tool results in greater material sweeping. As a result, the highest UTS and hardness values were obtained for welding connections created with the triangular profile pin tool. The study shows that the various input process parameters pertaining to tool revolving velocity, welding velocity, and tool-pin profile have a similar relationship on both hardness and ultimate tensile strength of weldment connection obtained with friction stir weld process. Hence, a similar trend or correlation has been observed in the variation of hardness and UTS. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Item Preparation and evaluation of mechanical properties of Al-6061 reinforced with graphite and fly ash of seed husk (Honge) particulate metal matrix composite(Institution of Engineering and Technology jbristow@theiet.org, 2013) Edrard, C.; Kapilan, N.; Herbert, M.A.The aim of this work is to study the mechanical properties of Aluminium alloy Metal Matrix Composites (MMCs) as they are gaining wide spread acceptance for automobile, industrial, and aerospace applications because of their low density, high strength and good structural rigidity. In the present work an attempt has been made to synthesize Al- 6061 with Graphite and fly ash of seed husk (Honge seeds) particulate metal matrix composites by using stir casting technique. The addition level of reinforcement is being varied from 0,4,6,8wt%. Preheated particle reinforcements are added to Al 6061 Alloy to improve wettability and distribution. Microstructural analysis was carried out for the above prepared composites by taking specimens from central portion of the casting to ensure homogeneous distribution of particles. Micro-hardness, tensile properties of the composites were studied as per the ASTM (E8M) standards. Microstructural characterization revealed fairly uniform distribution in the matrix. The Micro-Vickers hardness of the composite was found to decrease with increase in filler content in the composite. The density of both theoretically and experimentally of FA is higher then Gr. The tensile strength of the composites was found to increase confirming the dispersed graphite and fly-ash in Al-6061 alloy contributed in enhancing the tensile strength and wear resistance too of the composites.Item Effect of centrifugal and gravity casting technique over metallographic and mechanical properties of spheroidal graphite iron(2013) Desai Gowda, H.S.; Mukunda, P.G.; Herbert, M.A.The mechanical properties of cast iron depend on the graphite morphology and characteristics of metallic matrix. In spheroidal graphite iron these properties are affected by the nodule count, nodule percentage, nodularity, nodules per square mm, nodule types and size distribution. In this work an attempt is made to study of the effect of centrifugal and gravity casting process on the morphology and mechanical properties. A comparison of microstructure and mechanical properties of specimens of the cast are studied. It has been observed that the centrifugal effect produces an increase in rupture strain but hardness is unaffected. In microstructure it has been observed that the centrifugal effect produces an increase in the number of bigger nodules and decrease in the number of smaller nodules and an increase of nodules per square mm. It has no effect on nodularity percentage. The centrifugal casting process produces better mechanical properties.Item Experimental study on linear displacement measurement sensor using RGB color variation technique with PID controller(Institute of Electrical and Electronics Engineers Inc., 2017) Murthy, A.; Rao, S.S.; Herbert, M.A.; Karanth P, P.This study is based on experimental approach to linear displacement measurement using RGB color coding algorithm. This system is based on the auto-calibration procedure which can be implemented in a circuit, based on the temporal changes in the intensity of light, with the help of a light dependent resistor (LDR). The system consists of two LDRs and an LED placed on one side and an RGB color coded reflective paper on the opposite side. PIC microcontroller is used for powering the LED, processing of data for feedback control and to display the output on an LCD. LDR1 reading is used for displaying the relative linear distance, by mapping the voltage as a function of distance. This reading is used as a feedback to a PID controller to correct for the deviation in the measurement. Extensive experimental observations are conducted to analyze the reliability of the results in accordance to the wavelength of light reflected, the signal voltage and power output of the system. Investigation of the optimum positioning of the LED and the reflective RGB color coded paper is performed by repeatability analysis and hysteresis effects. Furthermore, the efficiency of the system is increased by implementing a PID controller upon investigating the different controller design, viz. P, PI and PID. A high resolution of 0.1 [mm] is obtained for such a simple and economical system, thereby making it highly efficient, in both minute measurements as well as over the entire bandwidth range of the visible light spectrum. © 2017 IEEE.Item Influence of modified cutting inserts in machining of Ti-6Al-4V alloy using PCD insert(Elsevier Ltd, 2018) Rao, R.; Rao, S.S.; Herbert, M.A.In modern manufacturing industries, the emerging needs of modern metal cutting operation are to increase the tool life with good surface finish and higher material removal rate. These objectives can be achieved by reducing the cutting temperature at the cutting zones with proper cooling system. The present work involves the experimental study of MQL application through the micro-holes drilled on the cutting inserts during turning of Ti-6Al-4V alloy using PCD inserts. The effect of the micropool lubrication of cutting insert on cutting temperature, surface roughness and tool wear have been compared with normal insert machining. It has been observed that in micropool lubrication method, cutting temperature was reduced by 30-33% over normal insert machining. Micropool lubrication reduced the flank wear to a maximum of about 20-30% over normal insert machining. The experimental result of the current research work indicates considerable benefits of surface roughness and tool wear through reduction in cutting temperature due to the perforation of the cutting insert. © 2018 Elsevier Ltd. All rights reserved.Item Active Upper Arm Exoskeleton - Design and Kinematic Analysis(Institute of Electrical and Electronics Engineers Inc., 2019) Santra, P.; Mukhopadhyay, A.; Debnath, B.; Herbert, M.A.; Bhaumik, S.The authors present a design of an exoskeleton with 6 active degrees of freedom (DOF) and 5 passive DOFs for rehabilitation of stroke survivors. Emphasis has been laid on making the model light weight and more ergonomic. Thus, concentration is mainly on 3D modeling of that device so that the mechatronic approach is compatible with human hand. The main choice of material for fabrication has been Nylon 6/10, owing to its lightweight and durable properties. The model was developed completely by the use of Computer Aided Design (CAD) and Computer Aided Engineering (CAE). Our model focuses on proposing a new actuation principle for better development of ergonomic shoulder design by incorporation of compliant passive springs and one passive revolute joint. Joints of the exoskeleton have been taken as simple revolute, possessing desired motion limits. Also forward kinematics has been established and the general workspace of the model has been developed. © 2019 IEEE.