期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2013
卷号：2
期号：9
页码：4905
出版社：S&S Publications
摘要：Forming is the most important manufacturing process. Forming is the process of converting the geometry tothe required shape. Forging, extrusion, rolling and bending are some of the important forming process. The formingprocess includes larger deformation of the structure either with temperature or without temperature application. But inthe every mechanical process certain defects exists due to the inherent resistance property of the material for forming itto the required shape. One type of defect is spring and is very important phenomenon which makes the object nonsuitablein case of rigid requirements. Spring back is mainly due to Bauchigner effect which allows the material tofollow different paths during loading and unloading cycles. All forming process will take places in the plastic region.So to analyse or to estimate spring back, nonlinear material properties which will accommodate stress strain relations inthe nonlinear regions are requiredIn the present work, spring back phenomenon with steel material is analysed using Finite element software Ansys. Twoparameters are considered for finding the spring back effect. Initially the sheet metal thickness effect on spring back isanalysed. The geometry is built and meshed with 4 noded quad elements which allow plastic properties. Euleriancontact definitions are created between the punch, die and sheet metal with large deformation effects. Thedisplacement loading is applied through the punch. Targe169 and contac172 elements are used for forming process.The results for vonmises stress, residual stress, plastic strain, spring back deformations are captured and tabulated.Similarly the analysis is continued with depth of forming process and its effect on spring back. The results shows withthe thickness spring back values are coming down but with the depth of deformation spring back values are increasing.So finite element simulation helps in finding the inaccuracy levels if the member material properties are given whichhelps in setting the tolerances for the geometry either for assembly or surface finishing operations. All the values likevonmises stress, residual stress, contact pressure, plastic strain and spring back are increasing with depth of the formingprocess.
关键词：Forming; spring back effect; Bauchigner effect; vonmises stress; residual stress; Ansys
