BITS Faculty Publications

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Author: search.filters.author.Kala, PrateekSubject: search.filters.subject.Mechanical Engineering

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Now showing 1 - 10 of 25
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    Effect of Arc Polarity on the Quality of Deposition in GTAW Welding-Based Additive Manufacturing Process: A Preliminary Study
    (World Scientific, 2022) Kala, Prateek
    A Gas tungsten arc welding (GTAW)-based additive manufacturing has a potential for manufacturing metallic parts with better dimensional accuracy and dense structure. This paper discusses the issues in the GTAW-based metal deposition process for the positive and negative polarity of the welding electrode in the direct current circuit. The effect of direct current electrode positive (DCEP) and direct current electrode negative (DCEN) polarity on GTAW-based metal deposition process has been discussed. The experimental study has been done with a constant voltage source of ESAB Caddy 2200i welding machine and the metal beads were deposited on the substrate plate of mild steel. The results of these experiments showed that the metal deposited using DCEN polarity has a better dimensional accuracy over DCEP polarity due to its stability in arc formation and proper transmission of heat. The experimental investigation showed that the DCEP polarity causes the deterioration of the tungsten electrode after a few trials. The work done in this paper will help to distinguish between the use of DCEP polarity and DCEN polarity in GTAW-based additive manufacturing process for depositing the metal with better dimensional accuracy and better surface finish.
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    An Investigation into Dimensional and Mechanical Properties of Multilayered Metallic Structure Deposited Using TIG Based WAAM Process
    (Springer, 2022-03) Kala, Prateek
    The wire and Arc Additive Manufacturing process has marked attention due to its higher deposition rates and lower fabrication cost. Many of the researchers have investigated the effect of process parameters of arc-based process like current, wire feeding speed, distance between two adjacent beads i.e. scan spacing on the forming quality and geometry of the deposited thin walled structures. This article gives an impression on the potential of the Wire Arc Additive Manufacturing process to manufacture a fully dense3D metallic structure. The experiments are carried out for the deposition of a fully dense 3D metallic structure with fine dimensional accuracy. A cuboid shaped structure has been successfully deposited by using GTAW based additive manufacturing system. The dimensional accuracy of the cuboid structure deposited by GTAW based additive manufacturing process has been evaluated in this paper. The results showed that the developed process can produce dense metallic structure with enhanced dimensional accuracy and mechanical properties.
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    Experimental investigations of TIG welding based additive manufacturing process for improved geometrical and mechanical properties
    (IOP, 2019) Kala, Prateek
    The welding based additive manufacturing process has a potential for producing functional 3D metallic component in a cost effective manner. Out of many welding based alternatives available TIG (Tungsten Inert Gas) based additive manufacturing process is one of the efficient processes. This article aims at developing TIG welding based additive manufacturing process for producing metallic parts with improved geometrical and mechanical properties. In this work authors have identified a process parameter condition by which components with good geometrical properties can be produced. The work reports least bead width deposited, for 1.2 mm filler wire, using wire arc based additive manufacturing system. The study performed on residual stress analysis of the deposited material showed compressive residual stresses throughout the sample. Usually welding process produces tensile stresses in the specimen which may reduce the product life. The compressive stresses reported in this study are considered good as they tend to increase product life. Authors have also addressed the reason for this unusual but favourable behaviour. This work would also help to develop automated TIG welding based metal deposition system to produce thin walled structures with improved mechanical and geometrical properties.
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    A Phase-wise Analysis of Machine Learning based Human Activity Recognition using Inertial Sensors
    (IEEE, 2020) Kala, Prateek
    Advancements in sensor technology, expanded analytical skills, and advancement in the field of Machine Learning (ML) and Deep Learning (DL), have all resulted in a substantial increase in popularity and wearable sensor performance for Human Activity Recognition (HAR). The real challenge is to spot the events in an unsupervised environment. In this study, we have tried to build a user-friendly, as well as an effective HAR system using an inertial sensor for eight everyday activities performed. The data was collected by our research team, using a single inertial sensor in a fully unsupervised setup. The eight tasks include: standing, sitting, sleeping, running, walking, cycling, upstairs and downstairs. This paper aims to present a detailed analysis and comparison for three primary aspects of a general HAR which contributes to the overall system performance. This involves analyzing the effects of pre-processing, comparing several extraction and selection methods for generating features from time-series data, and finally building and validating the performance of various classification methods to obtain the best combination of the three. The classification methods included in this study are Logistic Regression, K-Nearest Neighbors, Support Vector Machines and Artificial Neural Networks. After choosing the best parameters and techniques, we achieve a remarkable performance for recognizing the eight activities with an overall accuracy of 93.6%.
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    Development of a deposition framework for implementation of a region-based adaptive slicing strategy in arc-based metal additive manufacturing
    (Emerald, 2022-03) Kala, Prateek
    This study aims to develop and demonstrate a deposition framework for the implementation of a region-based adaptive slicing strategy for the Tungsten Inert Gas (TIG) welding-based additive manufacturing system. The present study demonstrates a deposition framework for implementing a novel region-based adaptive slicing strategy termed as Fast Interior and Accurate Exterior with Constant Layer Height (FIAECLH).
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    Process window identification for 3D printing low melting point alloy (LMPA) using fused deposition modelling (FDM)
    (Emerald, 2022-10) Kala, Prateek
    Fused deposition modelling (FDM) has gained popularity owing to its capability of producing complex and customized profiles at relatively low cost and in shorter periods. The study aims to extend the use of FDM printers for 3D printing of low melting point alloy (LMPA), which has applications in the electronics industry, rapid tooling, biomedical, etc.
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    Bibliometric Analysis-Based Review of Fused Deposition Modeling 3D Printing Method (1994–2020)
    (Mary Ann Liebert, 2021-08) Kala, Prateek
    This study aimed at the detailed bibliometric analysis (BA) of fused deposition modeling (FDM) to understand the trend and research area. Web of Science database was used for extracting data using keywords, and 2793 documents were analyzed. From the analysis, the most influential and productive authors, countries, sources, and so on were identified and corresponding interrelations were represented by a three-field plot. Lotka's law was derived for author productivity and its reliability was verified by the Kolmogorov–Smirnov (K–S) test. Bradford's law was used for identifying the core sources contributing to the field of FDM. From the trend topic analysis, it was found that initially the research was focused upon removing error related to deposition as well as part orientation, but with the course of time, it diversified to include topics such as optimization of printing parameters, materials, and applications. Based on the inferences from BA, the article also discusses on current research trend and highlights certain future areas for research work.
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    Trends, opportunities, and challenges in the integration of the additive manufacturing with Industry 4.0
    (Springer, 2022-09) Kala, Prateek
    The current study skims the trends, opportunities, and challenges in integrating additive manufacturing with Industry 4.0. The critical points of the existing review studies have also been discussed. The search query related to AM and Industry 4.0 was used for obtaining the information from two databases: Web of Science and Scopus. The papers were screened for duplicity and irrelevancy according to the topic of study. The bibliometric software R studio, Hiscite and Vosviewer were used for the analysis of downloaded articles. The bibliometric information related to the most-cited and productive authors, countries, sources, and universities was extracted. Lotka’s and Bradford’s law applicability to authors and sources, respectively, have been demonstrated. The interconnections between the authors, their respective countries and universities were represented with the help of three-field plot. The trend topics, keywords, and thematic evolution form the basis of a review of the cited work. The critical issues related to AM for achieving Industry 4.0 were reviewed. The insight of the case studies powering industry 4.0 was also presented. The challenges and limitations of AM’s implementation with respect to Industry 4.0 were highlighted. The conclusions were drawn out, and future scope was pointed out.
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    Experimental investigations of chemo-ultrasonic assisted magnetic abrasive finishing process
    (Inder Science, 2015-12) Kala, Prateek
    Chemo-ultrasonic assisted magnetic abrasive finishing (CUMAF) is a compound finishing process, which integrates the use of chemo-mechanical polishing (CMP), ultrasonic vibrations and magnetic abrasive finishing (MAF), to finish surfaces up to nanometre order within a short span of time. The present work is focused on design and fabrication of experimental set up to perform CUMAF. Using the developed set up, experiments were conducted on copper alloy work piece and the effects of five process parameters on percentage change in average surface roughness value (ΔRa) was recorded. The experiments were planned using response surface methodology. Experimental data were analysed using analysis of variance to understand contribution of various process factors and interactions on process response. Regression model was developed to predict the percentage change in surface roughness in terms of significant process factors and interactions. Further the developed model was validated and optimised using genetic algorithm to maximise the performance of the developed process
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    Experimental investigations into ultrasonic-assisted double-disk magnetic abrasive finishing of two paramagnetic materials
    (Sage, 2015-05) Kala, Prateek
    This article evaluates the finishing performance of ultrasonic-assisted double-disk magnetic abrasive finishing process on two paramagnetic materials (copper alloy and stainless steel) with different mechanical properties such as flow stress, hardness, shear modulus, and so on. The finishing experiments were performed based on response surface methodology. The results obtained after finishing have been analyzed to determine the effect of different process parameters such as working gap, rotational speed, and pulse-on time of ultrasonic vibration for both work materials and to study various interaction effects that may significantly affect the finishing performance by the process. The outcome of analysis for the two different work materials has been critically compared to understand the effect of the considered process parameters on the finishing performance of the process based on mechanical properties of the workpiece such as hardness. Furthermore, the scanning electron microscopy and atomic force microscopy were carried on the workpiece surface to understand the possible mechanism of material removal and the surface morphology produced after the finishing process.