H.M.A. Hussein

A feature–based approach to an integrated CAD/CAPP system in sheet metal blanking dies

Computer–aided process planning (CAPP) is considered to be the bridge that links computer–aided design (CAD) and computer–aided manufacturing (CAM). This paper describes a new approach to introduce computer–aided process planning into sheet metal blanking dies industry. The proposed system consists of two modules which are the CAD module and CAPP module. The first module is capable of reading 2D drawings of sheet metal parts provided by AutoCAD software, extracting geometric data from the drawings, building a die geometry that would produce the sheet metal part, and producing solid models of each die component. The second module receives the 3D blanking die components in IGES format and applies an intelligent feature extraction methodology in order to extract their manufacturing characteristics and produce a machining plan for each component. The proposed system is limited to prismatic die components. Finally, a case study is presented for demonstration purposes.

A framework for development of an intelligent system for design and manufacturing of stamping dies

An integration of computer aided design (CAD), computer aided process planning (CAPP) and computer aided manufacturing (CAM) is required for development of an intelligent system to design and manufacture stamping dies in sheet metal industries. In this paper, a framework for development of an intelligent system for design and manufacturing of stamping dies is proposed. In the proposed framework, the intelligent system is structured in form of various expert system modules for different activities of design and manufacturing of dies. All system modules are integrated with each other. The proposed system takes its input in form of a CAD file of sheet metal part, and then system modules automate all tasks related to design and manufacturing of stamping dies. Modules are coded using Visual Basic (VB) and developed on the platform of AutoCAD software.

Prediction the Springback in Air-Bending Process Using Neural Network Metamodel

To eliminate geometric deviations of sheet metal subjected to an air-bending process from the geometry required by the designer, it is necessary to predict the accurate value of the springback. Springback is the elastic deformation observed upon removal of the load during a bending process. In order to predict the springback amount, a multidimensional function should be approximated. In this paper, a neural network metamodel (NNM) based on the back propagation algorithm is introduced to predict the springback value. A verified nonlinear finite element model is developed to generate NNM training data. To select the training data for the NNM, computer generated D-optimal designs are utilized. The NNM developed model in this research can be used in determination of the springback value in sheet metal bending.

A CAPP/CAD for Sheet Metal Deep Drawing

The aim of this work is to develop an integrated system for facilitating the process of designing the drawing dies and their component. The developed system is based on the integration between Computer Aided Process Planning in Sheet Metal Drawn parts “CAPP”, and the Computer Aided Design in Deep Drawing Die components “CAD”. Both modules are coded using Visual Basic program and joined with AutoCAD. The CAPP module made to report the drawing load and to plot the shape of the drawn shell in each stage of the Axis-Symmetric Deep Drawing process. Based on the reported shell geometry, the dimensions of the die components are calculated and transferred to the CAD module. The CAD module, which is based on many data bases (standard parts, sheet metal data), plots the required deep drawing die components for each drawn stage on the AutoCAD monitor. A demonstrated example is presented to validate the developed system and to show that the system results are acceptable.

Computer Aided Design of the Die-Set for Sheet Metal Punching and Blanking Dies

Die-Set is one of the Punching/Blanking die components. It includes lower and upper shoes, guide posts and guide bushes. The High demand of Die-Set in industry resulted in the supply of specified die set from many manufacturing companies. The standard components in the market cover only the small and medium die sizes. In many cases, the designers need to build their own die-sets especially in case of progressive die design and non-tradition die sizes. In this paper, a CAD system for building a Die-Set is discussed. This system is built using Visual Basic (VB) interfacing with AutoCAD. The system covers all Die-Sets sizes (small, medium). The proposed CAD system is prepared to work as a standalone or as a subroutine for a blanking die design CAD system. It saves time in Die-Set design operation from hours to minutes. This module is a part of a series of studies to automate the design of sheet metal working tools.

Computer Aided Process Planning for Freeform Surface Sheet Metal Features in Automotive Industry

This paper describes computer aided process planning for a freeform surface; sheet metal features. Automotive body panels are always manufactured using thin forming sheets; the developed CAPP system consists of two modules which are feature recognition module based on STEP AP203 and a process plan module; two additional modules for automotive panel CAPP system and cost estimation module are also incorporated in the system of punch and bending operation. Stamped or punched features in generative shape design are used to design automotive panels; the generative CAPP system is written in visual basic 2008 language and implemented in several case studies demonstrated in the present work. Feature recognition of punched; stamped internal features in free form surface recognized in base of data exchange files using STEP AP203 ISO-10303-21.