Talk on "Product and Process Design for Double-Sided Incremental Forming"
Speaker: Dr. Rakesh Lingam (Postdoctoral Research Fellow, POSTECH, South Korea)
Title: Product and Process Design for Double-Sided Incremental Forming
Incremental Sheet Forming (ISF) is a die-less forming process that uses simple tools to form complex three-dimensional parts. In ISF simple tools are programmed to move in predefined paths giving shape to the peripherally clamped sheet in series of local deformations. Double-Sided Incremental Forming (DSIF), uses two tools (one on either side of the sheet), to form the components. Depending on the component geometry, either of the tools forms the geometry while the other provides local support. Complex geometries can be formed in a single setup using DSIF.
Simple mechanics-based models are developed to accurately estimate tool and sheet deflections during DSIF and are compensated to enhance accuracy. The flexibility of DSIF to form complex geometries is harnessed by recognizing features from topology and geometry information of boundary representation models. A scaled-up DSIF machine capable of forming components up to 1150 mm X 1150 mm, having both the displacement as well as force control options, is designed and developed. Thin plates and shells theory used to predict the sheet deflection, is valid only when the ratio of sheet maximum dimension to thickness is between 10 and 100. Hence, for large components, a multistage methodology is attempted to enhance accuracy.
The anisotropic effect studies showed that the thickness is low along low anisotropy direction. This results in low stiffness and high spring-back both in radial and depth directions. The residual stress development mechanism in ISF is studied using Finite Element Analysis, and the residual stresses on formed components are measured using the X-ray diffraction technique. Profile variation with tool movement showed that bending and unbending take place at a point when the tool moves over it, resulted in compressive residual stresses on the outer surface and tensile residual stresses on the inner surface of the sheet.
Speaker Bio: Dr. Rakesh Lingam is a Postdoctoral Research Fellow at the Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, South Korea. Dr. Lingam obtained his doctoral degree in mechanical engineering from the Indian Institute of Technology Hyderabad and Master’s degree from the Indian Institute of Technology Kanpur. He also has four years of experience as a software engineer. His research interests include metal forming, plasticity, numerical analysis of forming processes, material modelling, fracture mechanics, computer-aided design, and manufacturing (CAD/CAM), flexible manufacturing processes.
Event Date: 20th November, 2019(Wednesday)
Event Time: 11:30 AM
Venue: Room No. 119