New Ductile Fracture Model of Hexagon Flange Nut in Cold Forging

• Main Authors: SHEN,YU-HOW, 沈昱豪
• Other Authors: HSH,CHAO-HO
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/55k4zz

碩士 === 國立高雄應用科技大學 === 模具工程系 === 106 === This study mainly predicts the crack position of the outer hexagonal flange nut during cold forging, and finds that most of the fracture forms exhibit shear stress damage close to 45°, instead of the tensile force proposed by Cockcroft and Latham stress caused damage, so a new ductile failure mode was proposed to verify The new ductile failure mode is mainly based on the ductile failure caused by the strain energy generated when the maximum shear stress occurs, and the theoretical integral is converted into a sub-program and added to the ductile failure module of the finite element analysis software DEFORM. The composite extrusion case is simulated to predict whether the fracture form meets the requirements. Then, based on the discussion of this paper, the hex flange nut forming is used to simulate the fracture form and stress analysis, and finally the forging failure mode commonly used for forging is Normalized Cockcroft and Latham as a comparison of its applicability. After comparing the results of the previous two examples, it is found that the Normalized Cockcroft and Latham modes are consistent with the new ductile failure mode in predicting the rupture position, and the new ductile failure mode is more accurate in predicting the rupture trend.