Department of Mechanical engineering

Permanent URI for this collectionhttp://localhost:4000/handle/123456789/1921

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Subject: search.filters.subject.Design of experiments (DoE)

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Now showing 1 - 5 of 5
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    Multi-objective optimisation in the microturning of cobalt chromium with coated and uncoated tools using the grey relational analysis
    (Inder Science, 2015-06) Mathew, Nitin Tom
    In this work, the microturning of cobalt chromium has been carried out using coated and uncoated tungsten carbide inserts. The experiments were conducted as per the design of experiments (DoEs) approach using the L9 orthogonal array by varying the spindle speed (S), feed (F) and depth of cut (Dcut) at three levels. The output parameters considered are the material removal rate (MRR), surface roughness (Ra) and tool wear (TW). The significant parameters and their levels were identified using analysis of variance (ANOVA) and response graphs. It is observed that the significant microturning process parameters are found to be different for different tool/workpiece combinations, for achieving a higher MRR, lower Ra and low TW individually. Therefore, a multi-objective optimisation using the grey relational analysis was performed considering MRR, Ra and TW together and the optimum level of input parameters were identified to achieve high MRR, low Ra and low TW together.
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    Optimization of process variables to improve the mechanical properties of FDM structures
    (IOP, 2019) Kala, Prateek
    This paper presents, the experimental methodology to optimize the process variable for Fused deposition modeling (FDM) fabricated parts. Process variable plays an important role to influence the mechanical and physical properties of a component. In this study, 3 important process variables, i.e., layer thickness, infill percentage, and print speed were considered to carry out their effect on Tensile and compressive strength of ABS (Acrylonitrile Butadiene Styrene) fabricated specimens. The experiments process based on Design of experiment (DOE) methodology. The recent studies only focused one process variable at a time, and its effect on mechanical properties of FDM processed part. But the present study gives an insight into 3 process variable influence on the FDM manufactured components. Obtained results were analyzed by the DOE and optimization techniques. The experimental results highlighted that, out of the 3-process variable, layer thickness and infill percentage have a major impact on the mechanical properties of FDM structures. The remaining one process variable has less influencing characteristics, but it comes into effect in a certain domain. The results give the functional relationship between process variables and the mechanical properties of the component. This study shows very promising results to enhance the strength of a part fabricated by using FDM technology.
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    Experimental Investigation Using Response Surface Methodology for Condition Monitoring of Misaligned Rotor System
    (ASME, 2021-08) Marathe, Amol; Jalan, Arun Kumar
    Misalignment is one of the key reasons for vibrations in most of the rotating system. The present study focuses on interactions among speed, load, and defect severity by investigating their effect on the system vibration. Response surface methodology (RSM) with root-mean-square (RMS) as a response factor is used to understand the influence of such interactions on the system performance. Experiments are planned using design of experiments, and analysis is carried out using analysis of variance (ANOVA). It is observed that speed has a remarkable effect on RMS value in both parallel and angular types of misalignment and affects the system performance. RSM results revealed that a change in load has less impact on vibration amplitude in case of horizontal and vertical directions, but there is a significant variation in RMS value in axial direction for both types of misalignment. A slight increase in the RMS value with an increase in defect severity is observed in the axial direction. These observations will help to understand the misalignment defect and its effect in a better way.
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    Condition Monitoring of Misaligned Rotor System Using Acoustic Sensor by Response Surface Methodology
    (ASME, 2022) Jalan, Arun Kumar; Marathe, Amol
    Misalignment is among the most common causes of vibrations in rotary machinery. Modern machinery is complicated and installing a sensor might be tricky at times. As a result, noncontact type sensors are critical in such situations. The present study investigates the influence of combinations between speed, load, and fault severity upon system vibration by employing acoustic sensor. Although acoustic sensor is used in angular fault diagnosis, however, this is the first attempt to combine the noncontact type of sensor and response surface methodology (RSM) to study the influence of misalignment upon system vibration and the factors that induce system vibrations in a misaligned rotor system. To investigate the effect of these interactions on system performance, RSM with root-mean-square (RMS) as a response factor is used. Design of experiments is used to prepare experiments, while analysis of variance (ANOVA) is used to analyze the results. Speed has a significant impact on RMS value in both parallel and angular types of misalignments and it severely affects the system's performance. According to the RSM findings, a change in load influences vibration amplitude. With increasing defect severity, the change in RMS value was not particularly significant. The outcome of RSM using acoustic sensor was found well aligned with the conclusion drawn using RSM study with vibrational sensor.