TJ911 : Experimental investigation of ultrasonic vibration on frictional behavior of the sheet mextals during the draw bending process baxsed on the measuring of deformation distribution
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2023
Authors:
Mohammad Jorvand Khosroabadi [Author], Mahdi Gerdooei[Supervisor], Mahdi Vahdati[Supervisor]
Abstarct: Basically, when the surfaces of two objects slide on each other, the friction occurs between them. Applying ultrasonic vibrations to one of these objects reduces the friction force between them, which has significant benefits in the forming and machining processes. Therefore, ultrasonic vibrations can be introduced as a lubricant with higher efficiency and less pollution. In this research, ultrasonic vibrations on the forming force, friction coefficient, and plastic strain in the stretch- bending process were experimentally studied. Experimental tests in dry condition and with nylon lubricant were designed. To produce, transmit, and apply ultrasonic vibrations, it is necessary to use ultrasonic equipment consisting of a generator, transducer, booster, and horn which was added to the forming tools. The experiment is performed on DC04 steel sheet such a way that after cutting the samples, meshing was done on them by a silk screening method. Stretch-bending was performed in the states with and without lubricant as well as with and without the presence of ultrasonic vibrations for two forming depths of 15 and 21 mm. It showed that the application of ultrasonic vibrations at a depth of 15 mm results in a reduction of 12.5 and 4.5 percent of forming, respectively, in the conditions of with and without lubricant. Also, applying ultrasonic vibrations at a depth of 21 mm will reduce the forming force by 7.95% and 13.45%, respectively, under the conditions of with and without the use of lubricant. In addition, the application of ultrasonic vibrations to the punch reduces the friction coefficient by 44% and 50%, respectively, in the condition without use and with the use of nylon. Also, it was found that by assisting the vibration, more continuous distribution of strain was obtained leading to higher formability of the sheet.
Keywords:
#Stretch-bending #Ultrasonic vibrations #DC04 sheet #Forming force #Friction coefficient. Keeping place: Central Library of Shahrood University
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