W.L. Chan

An integrated FEM and ANN methodology for metal-formed product design

In the traditional metal-formed product development paradigm, the design of metal-formed product and tooling is usually based on heuristic know-how and experiences, which are generally obtained through long years of apprenticeship and skilled craftsmanship. The uncertainties in product and tooling design often lead to late design changes. The emergence of finite element method (FEM) provides a solution to verify the designs before they are physically implemented. Since the design of product and tooling is affected by many factors and there are many design variables to be considered, the combination of those variables comes out with various design alternatives. It is thus not pragmatic to simulate all the designs to find out the best solution as the coupled simulation of non-linear plastic flow of billet material and tooling deformation is very time-consuming. This research is aimed to develop an integrated methodology based on FEM simulation and artificial neural network (ANN) to approximate the functions of design parameters and evaluate the performance of designs in such a way that the optimal design can be identified. To realize this objective, an integrated FEM and ANN methodology is developed. In this methodology, the FEM simulation is first used to create training cases for the ANN(s), and the well-trained ANN(s) is used to predict the performance of the design. In addition, the methodology framework and implementation procedure are presented. To validate the developed technique, a case study is employed. The results show that the developed methodology performs well in estimation and evaluation of the design.

Tooling Design and Fatigue Life Evaluation via CAE Simulation for Metal Forming

Cold forming tools are subjected to extremely high pressure. Fatigue is one of the major failure modes on metal forming tools especially on cold forging process. There are many factors influencing the fatigue life such as material properties, interfacial friction, loading, and product geometry etc. and thus it is possible to greatly enhance the tooling life with subtle design change on the product, tooling or process parameters. This paper is aimed to address some key design parameters for tool fatigue life and they should be considered as more in-depth as possible at up-front design stage to eliminate any late design changes and unexpected tooling failures. To realize this goal, an efficient framework for tooling design and fatigue life evaluation which considers different design factors and integrated product, tooling and process design via simulation is proposed. It also provides a platform to systematically integrate different design and engineering tools to support tooling design and design solution evaluation through geometry representation, formability analysis, identification of fatigue failure area and die life prediction. A case study for the tooling design for production of a vehicle wheel disc is presented to demonstrate the implementation of the proposed design and analysis framework.