Table Of Content

Engineering Design and Rapid Prototyping Ali K. Kamrani Emad Abouel Nasr ● Engineering Design and Rapid Prototyping Ali K. Kamrani Emad Abouel Nasr Industrial Engineering Department Fatimah Alnijris’s Research Chair University of Houston for Advanced Manufacturing Technology Houston, TX, USA Industrial Engineering Department and Faculty of Engineering Fatimah Alnijris’s Research Chair King Saud University for Advanced Manufacturing Technology Riyadh, Saudi Arabia Industrial Engineering Department and King Saud University Mechanical Engineering Department Riyadh, Saudi Arabia Faculty of Engineering [email protected] Helwan University Helwan, Egypt [email protected] ISBN 978-0-387-95862-0 e-ISBN 978-0-387-95863-7 DOI 10.1007/978-0-387-95863-7 Springer New York Dordrecht Heidelberg London Library of Congress Control Number: 2010932806 © Springer Science+Business Media, LLC 2010 All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com) To my wife Sonia and sons Arshya and Ariya Ali Kamrani To my parents, wife, and children Nada, Haidy, and Amr Emad Abouel Nasr Preface Engineering design process consists of a set of activities arranged in a specific order with the clearly identified inputs and outputs. The process of engineering design is an iterative that supports the decision-making activities involved. Each activity in the process takes an input and transforms it into an output of some value defined by design specifications and objectives. The output of the process is either a product, a process, or a service. The objective of the process is to satisfy customer requirements and management objectives. This process is considered efficient when the output of the process satisfies general customers and defined requirements, meets management objectives and customer deadlines, and all these with less costs and resources. Establishing objectives and criteria, synthesis, analysis, construction, testing, and evaluation are considered as fundamental elements within the design process. Steps in the Engineering design process are illustrated in Fig. 1. These steps and further described below: 1. Identify the Need/Problem: This step is not always realized by engineers. Problems are typically identified by the market and customers and then passed on to the engineering group to search and develop solutions. Engineering Design Process Select Best Possible Solu(cid:31)on Fig. 1 Engineering design process vii viii Preface 2. Research the Need/Problem: This step is of importance since a solution to the defined problem or portion of the problem may have already existed. Through proper research, time and money can be easily saved. 3. Develop Possible Solutions: In this step, the engineering group will propose different solution alternatives that will solve the problem. These possible solutions are made while taking into consideration the information found in the pre- vious steps. 4. Select Best Possible Solution: The engineering group will then use the defined criteria and other methodologies to select the best possible solution. The param- eters on which the engineering group determine if it is the best possible solution may vary depending on the defined constrains and/or the design criteria estab- lished at the beginning of the engineering design process. 5. Construct a Prototype: In this step, the engineering group proceeds to construct a prototype of the selected solution. Once the prototype is built, testing is performed to validate the proposed design solution. If the design does not meet the required performance, the engineering design process is repeated until a sat- isfactory solution is implemented. New global economies and global markets changed business practices and focused on the customer as the major player in the economy. In order to compete in this fast-paced global market, organizations need to produce products that can be easily configured to offer distinctive capabilities compared to the competition. Furthermore, organizations need to develop and implement new engineering meth- ods (e.g., modularity), and apply advanced techniques in design (e.g., Feature- Based Design) and technologies (e.g., Rapid Prototyping) to react rapidly to required changes in products and market trends and to shorten the product development cycle, which will enable them to gain more economic competitiveness. This requires that the tasks needed to develop products be made in parallel, starting at the early stages of product development. By developing such techniques, organizations will be able rapidly to design changed or new products, to change parts of a product, or to change manufacturing facilities to a new version of a product. The concept of modularity can provide the necessary foundation for organizations to design products that can respond rapidly to market needs, and allow the changes in product design to happen in a cost-effective manner. Modularity can be applied to the engineering design processes to build modular products. An impor- tant aspect of modular products is the creation of a basic core unit to which different components (modules) can be fitted, thus enabling a variety of versions of the same module to be produced. The core should have sufficient capacity to cope with all expected variations in performance and usage. Components used in a modular product must have features that enable them to be coupled together to form a new product. Figure 2 illustrates the scope of modular design methodology. Computer-aided design (CAD) and manufacturing (CAM) systems are based on modeling geometric data. The main advantage of CAD/CAM systems is the ability to visualize product design, and support design analysis and manufacturing acti- vates. CAD/CAM systems need the standardization that gives them the ability Preface ix Design Concept (Re)Formulation Optimization Models Design for and Sub-System Modularity (DFMo) Generation Design for Simplification of Assembly (DFA) Product Structure y arit Selection of Material Knowledge-Based ul and Primary Process D Engineering and d o for Near Net Shape Decision Trees M n for FDeaessiibglne /COopnticmeupmt F MaMteorriael sE, cPornoocmesicses g and Machines si e D Design for Manufacture M Template-Based Decision Trees and Process Planning Group Technology Optimization Models Modular and Manufacturing Manufacturing Cells Cells Generation Fig. 2 Design for modularity life cycle to communicate to each other. Different CAD or geometric modeling packages store the information related to the design in their own databases, and the structures of these databases are different from each other. As a result, no common or standard structure has been developed that can be used by all CAD/CAM packages. Therefore, a feature-based approach using IGES standard will provide the required standardization to achieve the integration between CAD and CAM. Figure 3 illustrates the stages that CAD/CAM and other advanced tools and technologies are used to support, and integrated and intelligent engineering design life cycle. Rapid Prototyping (RP) is a technique for direct conversion of three—dimen- sional CAD data into a physical prototype. RP allows for automatic construction of physical models and has been used to significantly reduce the time for the product development cycle and to improve the final quality of the designed product. Before the application of RP, computer numerically controlled (CNC) equipments were used to create prototypes either directly or indirectly using CAD data. In RP process, thin-horizontalcross-sections are used to transform materials into physical prototypes. Steps in RP process cycle are illustrated in Fig. 4. In the RP process, CAD data are interpreted into the Stereolithography (stl) data format. The stl is the standard data format used by all RP machines. By using “stl”, the surface of the solid is approximated using triangular facets, with a normal vec- tor pointing away from the surface in the solid. Within the last few years, corpora- x Preface s si y al An Manufacturing and g Production n uri ct ufa Process Planning n and CAPP a M d Variety and an CAD/CAE Complexity gn Design for Manufacture Analysis esi and Assembly Analysis D Analysis and Re-Design Specifications Rapid Prototyping and Concepts CAD Time Fig. 3 CAD/CAM application for EDP Functional & Physical Specifications Tools for CAD Tool for Decomposition Sculptural Geometric Design & Design and Modular 3D Model Styling Components and Subassemblies Rapid STL File Analysis Prototyping & Editing Testing Product Product Mfg. & Planning & Process & Process Assembly Development Testing Fig. 4 Generic RP process cycle