Computer aided process planning for non-axisymmetric deep drawing products
In general, deep drawing products have various cross-section shapes such as cylindrical, rectangular and nonaxisymmetric shapes. The application of the surface area calculation to non-axisymmetric deep drawing process has not been published yet. In this research, a surface area calculation for non-axisymmetric deep drawing products with 
elliptical shape was constructed for a design of blank shape of deep drawing products by using an AutoLISP function of AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. However, the application of the system to non-axisymmetric components has not been 
reported yet. Thus, the CAPP system for non-axisymmetric deep drawing products with elliptical shape was constructed by using process sequence design. The system developed in this work consists of four modules. The first is recognition of shape module to recognize non-axisymmetric products. The second is a three-dimensional (3-D) modeling module to calculate the surface area for non-axisymmetric products. The third is a blank design module to create an oval-shaped blank with the identical surface area. The forth is a process planning module based on the production rules that play the 
best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. Especially, the drawing coefficient, the punch and die radii for elliptical shape products are 
considered as main design parameters. The suitability of this system was verified by applying to a real deep drawing product. This CAPP system constructed would be very useful to reduce lead-time for manufacturing and improve an accuracy of products.
Expert systems for metal forming
In this paper some new results are presented on the development of a Knowledge Based Expert Systems for metal forming applications. The system is aimed to be capable of generating feasible process plans for various sheet and bulk metal forming modules. The elaboration of this expert system is based on the principles of group technology. A hybrid component classification system combining both geometrical and technological attributes of the components to be produced is developed to form part families. Utilizing a generative process planning approach feasible process plans can be generated which can further be manipulated by the user interactively. Besides the sequence of operations and the detailed process plans, the system provides the necessary technological and tool design parameters, as well.
Analysis of Sheet Metal Forming to Axisymmetric Shapes
The objective of this study was to develop an analytical method of predicting the stress and strain distribution in a metal sheet formed into a cup or other axially symmetric geometry. The analysis is done using the finite element method based on the deformation theory of plasticity; the elastoplastic computations account for the large deformation associated with sheet forming operations. The theory behind the computer program is discussed in detail. Examples are given of the strain distributions induced in cups drawn to depths comparable with their diameters. The results also give the stresses, thickness changes, and forming force required. Some comparisons between the calculated and measured strains are discussed, and they show good agreement.