Papers by Keyword: Design for Manufacturing

Abstract: In the olden days the motto was "I designed it; you build it!" Design engineers worked alone and Designs were then thrown over the wall leaving manufacturing people with the dilemma how to manufacture. Often this delayed both the product launch and the time to ramp up to full production. In the new good days manufacturability can be assured by developing products in multi-functional teams with early and active participation from Manufacturing, Marketing (and even customers), Finance, Industrial Designers, Quality, Service, Purchasing, Vendors and factory works. The need for a holistic approach between design and manufacturing is required. The two concepts Design for Manufacturing & Design for Assembly has become the need of the hour. The heart of any design for manufacturing system is a group of design principles or guidelines that are structured to help the designer reduce the cost and difficulty of manufacturing an item.Realisation of Cryogenic thrust chamber includes various manufacturing processes like Forming, Welding, Machining and Brazing. During initial stages of Thrust chamber realisation problems like Forming of 1.7m long nozzle divergent from thin sheets, welding of various intricate geometries & assembly of critical parts were observed. Subsequently these problems were studied based on the holistic approach of Design for manufacturing & design for assembly. Improvements based on the above study were considered in design & critical processes modifications resulting in successful and timely realization of the thrust chamber.

Abstract: In the process of Fused Deposition molding (Fused Deposition Modeling, FDM), because the 3 d design is disconnected with manufacturing (or process), and prototype and precision is influenced by many factors, there are many disadvantages such as much design rework, difficult processing, low efficiency and high cost. Based on the concept of Design for Manufacturing ((Design for Manufacturing, DFM), this paper analyzes several factors that influence the forming accuracy, and puts forward the corresponding solutions to improve rapid prototyping manufacture parts strength and forming precision, combined with the actual rapid prototyping processing. It has certain reference value in the study of parameter selection and structure improvement of FDM process oriented component design.

Abstract: Fixture systems have a great importance in modern manufacturing and assembly because of the high number of scenarios in which they are used. Fixture design is a complex task since the system effectiveness depends both on position and type of locators. Several authors deal with the problem of determine the most suitable design for fixture systems but their investigation is commonly limited to the evaluation of the effects due to the locators position. In the present work a design method is proposed to evaluate the fixture systems considering also the locators type. Since it is possible to model the fixtures as multi-performance systems, the comparison is performed by introducing appropriate sensitivity indexes. The effectiveness of the design method is proved through the application to an automotive case study.

Abstract: Application of Design for Manufacturing (DFM) and Design for Assembly (DFA) methodologies can be beneficial to industries involved in the design and development of products. Improper design decisions are responsible for higher manufacturing cost for a product. Thus it is important to include DFMA by combining principles of both DFM and DFA principle early in the design process. This paper presents a case study of manufacture and assembly costs estimation during the design phase of washing machine and which is to be manufactured in company located in India, and intends to make this economically feasible. Solidworks and Solidview software tool were used to generate CAD models which were further analysed using DFMA software tool. The result obtained was accepted by industry and match with the market value of washing machine.

Abstract: In the light of growing global competition, organizations around the world today are constantly under pressure to produce high-quality products at an economical price. The integration of design and manufacturing (DFM) activities into one common engineering effort has been recognized as a key strategy for survival and growth. In this paper, the importance of DFM and parts information model was introduced in today's manufacturing enterprise. It describes the classification of parts information model; namely: product models, process models and cost models, the main content and research status that the model contained. The author has proposed a semantic network description method of the manufacture parts information of and details its main content, which is the core of this paper.

Abstract: It is widely acknowledged that decisions made in the early design stages have a greater influence on the final product than those made in the later stages. In the early stages of a conventional design process, composite structures are designed without sufficient consideration being given to limitations of composite manufacturing process. Quite often some of composite designs cannot be produced with special performance requirement or cannot be produced at a reasonable cost. To resolve this drawback and achieve the manufacturable designs for composite product, a knowledge-based decision-making tool was introduced and applied to support the composite design optimization. Firstly, the current development of DFM techniques in composite domain, as well as the main problems in performing DFM for composites is analyzed. Secondly, some of key issues in the composite manufacturing process that should be considered during the composite design process are presented. And then, a knowledge-based DFM system for composite manufacturing process is proposed, focusing on the system decision task, the system framework and the flowchart. Finally, the system is illustrated with a case in autoclave process.

Abstract: This paper presents an original approach in mechanical design to integrate the manufacturing constraints in the final CAD model. A specific user-interface is proposed to integrate manufacturing constraints (for example tolerances) and manufacturing consequences (for example roughness or hardening) into the model. One of the important consequences of manufacturing processes is the generation of residual stresses into the part. An appropriate tool has been developed and used as a design tool to manage the global evolution of residual stresses in the mechanical part and to obtain the deformed geometry resulting from the applied manufacturing plan. These results could eventually be used in fatigue simulation. To support the model, a database is used for the integration of residual stresses from stored experimental results, analytical or numerical calculations. An example of a metal sheet, laminated and deformed by shot peening is given, the deformed geometry is rebuilt and compared to the experimental results.