TJ892 : Numerical and experimental analysis of Jamming Phenomenon in Positioning of Circular-Section Workpiece on Horizontal Surface
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2023
Authors:
Sattar Hazrati [Author], Hadi Parvaz[Supervisor], Seyed Vahid Hosseini[Advisor]
Abstarct: Workpiece jamming in a fixture may cause improper positioning, damage to the workpiece, and even the fixturing elements. Jamming is defined as the sudden and unwanted immobilization of a workpiece during its loading/unloading into the fixture. Investigation of workpiece jamming in the fixture and prediction of its occurrence during the fixture design process induce modification of the fixturing plan, reduction of the fixture fabrication costs, and decreasing jamming-related consequences. The present study focuses on the numerical and experimental analysis of workpiece jamming with the circular cross-section in a fixture to calculate the jamming-in travel of the workpiece. For this purpose, numerical analysis of circular workpiece on the horizontal surface is conducted using Abaqus software. A theoretical model that was developed in the previous study is used to validate the predictions of the suggested numerical model. The main validation of the numerical predictions is conducted through the experimental tests. For validation of the numerical predictions, an experimental setup is designed and fabricated with three circular cross-section workpieces with diameters of 40, 50, and 60 mm. Experimental tests were conducted to measure the friction coefficient between the circular workpiece, baxse plate, and palm. The friction coefficient measurement tests were repeated 18 times for each workpiece at two angles of zero and 180 degrees. After the measurement of the friction coefficients, the jamming-in travel of the workpiece was measured using image processing techniques and a calibrated ruler installed on the laboratory set, and data collection with an angular encoder. These experiments were also repeated 10 times for each workpiece and data were collected. According to the obtained experimental values, the numerical analysis of the process was done with Abaqus software. By comparing the experimental results of jamming-in travel to the predictions of the suggested numerical model, the worst-case error values were determined as 12.4% for the workpiece with a diameter of 40 mm and 6.18% for the workpiece with a diameter of 50 mm and 8.53% for the workpiece with a diameter of 60 mm.
Keywords:
#Jamming Phenomenon #Peg in hole #Fixture #Friction Coefficient #Fixture Design #Circular workpiece #Jamming analysi Keeping place: Central Library of Shahrood University
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