TJ652 : Feasibility study on piercing of mextallic tubes by using elastomeric tools pressure
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2019
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Abstarct: Piercing of mextal tubes is a process to create a hole in the tube to produce multi-way industrial joints. Using traditional methods of this process doesn't result in optimal cutting edges quality. Traditional methods of piercing such as using drills have disadvantages such as pre-drilling, impossibility of clamping at the inner surface of the tube, circular shape restriction and cutting edge protrusion. This process has recently been performed using fluid as a piercing tool. Using of fluid has also problems such as sealing and expensive tools and equipments. In order to overcome the above mentioned problems; in this study, the piercing of aluminum tube was investigated experimentally and numerically using elastomeric tooling in a new method. The elastomeric tooling is widely used in the aerospace and automotive industries due to its high flexibility, creation optimum surface quality and reduced manufacturing cost. Numerical analysis of the process was carried out in ABAQUS software assuming that the elastomeric tool is a non-compressible hyperelastic material with the Moony-Rivlin behavioral model. To predict the ductile fracture of tube, the Gurson-Tvergaard-Needleman (GTN) damage model was used as a micromechanical model in ductile fracture of porous mextals. In order to determine the parameters describing the GTN fracture model, firstly, the experimental tensile test of the standard specimens and the finite element simulation were performed by applying the GTN failure criterion and comparing the force-displacement diagram of the experimental tensile test. The parameters of this damage model were determined by the inverse calibration method. Finally, the obtained parameters were used to simulate the piercing process in piercing die. In the tube piercing tests, the maximum force of the process, tube geometry especially thickness, and also effect of hardness of the used elastomers were investigated. The material used was 6061 aluminum alloy tube with three types of thickness 1 mm, 1.4 mm and 1.8 mm. The hole diameter was assumed to be 12 mm in the piercing process. The results showed that if the process parameters such as material, geometry and thickness of the tube and suitable hardness of elastomeric tool are selected correctly, the use of elastomeric tools for mextal tube piercing is possible and results in a good quality cutting surface. Also, the amount of piercing force in the experimental tests for different tube thicknesses and different harnesses of the elastomeric tools is in good agreement with the results of numerical simulation.
Keywords:
#mextal tube piercing #Elastomeric tool #Finite element simulation #GTN damage model #Aluminum tube Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
Visitor: