Sunday, December 5, 2010

Sheet Metal Forming Processes: Constitutive Modelling and Numerical Simulation


Springer | 2010-06-29 | ISBN: 3540881123 | 350 pages | PDF | 5 MB

The book gives a synthetic presentation of the research performed in the field of sheet metal forming simulation during more than twenty years by the members of three teams: the Research Centre on Sheet Metal Forming – CERTETA (Technical University of Cluj-Napoca, Romania); AUTOFORM software-house company from Zürich, Switzerland and VOLVO automotive company from Sweden. The first chapter reminds some fundamental topics of the theory of plasticity. A more extended chapter is devoted to the presentation of the phenomenological yield criteria, emphasizing the formulations proposed by the CERTETA team (BBC models). The sheet metal formability is discussed in a separate chapter. After presenting the methods used for the formability assessment, the discussion focuses on the forming limit curves. In this context, the authors emphasize their contributions to the mathematical modeling of forming limit curves. The aspects related to the implementation of the constitutive models in finite-element codes are discussed in the last chapter of the book. The performances of the models are proved by the numerical simulation of various sheet metal forming processes: hydroforming, deep-drawing and forming of the complex parts. The book is useful for the students, doctoral fellows, researchers and engineers who are mainly interested in the mechanical modeling and numerical simulation of sheet metal forming processes. Modeling and numerical simulation of sheet metal forming processes.

Tuesday, November 2, 2010

Book: Applied Metal Forming


Henry Valberg, "Applied Metal Forming: Including FEM Analysis"
Cambridge University Press | 2010 | ISBN: 0521518237 | 460 pages | PDF | 11,3 MB

Applied Metal Forming: Using FEM Analysis describes metal forming theory and how experimental techniques can be used to study any metal forming operation with great accuracy. For each primary class of processes, such as forging, rolling, extrusion, wiredrawing, and sheet-metal forming, it explains how FEA (Finite Elements Analysis) can be applied with great precision to characterize the forming condition and in this way optimize the processes. FEA has made it possible to build very realistic FEM-models of any metal forming process, including complex three-dimensional forming operations, in which complex products are shaped by complex dies. Thus, using FEA it is now possible to visualize any metal forming process and to study strain, stresses, and other forming conditions inside the parts being manufactured as they develop throughout the process

Thursday, October 21, 2010

Free/Open Source Pre-Post Processor

Finite Element Link
1. 6DOF
2. CASE Software
3. COSMOS/Exchange
4. Engineering Software Center
5. The FEA Portal
6. The FEM Site
7. FEMOOP

For complete link click here

Springback Behavior Prediction of Benchmark Problem II Numisheet 2008 Model Under Smooth Drawbead


An accurate modelling of the sheet metal deformations including the springback prediction is one of the key factors in the efficient utilisation of Finite Element Method (FEM) process simulation in industrial application. The accurate simulation of the drawing products will not be useful since springback will occur after the tools are removed off the drawing die set. The springback prediction should be further performed to see the final formed shape after the elastic recovery. The elastic behaviour of the metal will be contributing to other geometrical forming defects, such as thinning and wrinkling.
This paper presents an evaluation of a standard benchmark model defined as Benchmark II of Numisheet 2008. This is an S channel model with various drawbeads. For benchmark evaluation purpose, only smooth drawbead is chosen and two finite element application packages based on implicit codes i.e DYNAFORM and AUTOFORM are utilised for simulating the forming process as well as the calculation of the springback distortion.
Results are presented with comparison of the two packages. The simulation strategy involved are discussed to provide a general approach that may influence the results. The results are also revealing the influence of the smooth drawbeads when this type of bead is introduced to the model.
The simulation results show that the application of implicit finite element code in predicting springback distortion is sufficiently effective. The two simulation results from different commercial packages are in a good agreement. One thing that should be taken into consideration for further research is accommodating springback to obtain a better geometrical accuracy.

Keywords: Smooth Drawbead, DYNAFORM, AUTOFORM, Springback