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Technical graphics is an integral part of the engineering design process through which engineers and drafter/designers generate new ideas and solve problems. Traditional engineering design consists of closely related steps that flow both sequentially and back and forth. Many industries in the United States are changing their design methodology from a linear/sequential activity to a team approach in which all parts of the company are working on a project simultaneously.
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| DESIGN Design is the process of conceiving or inventing ideas mentally and communicating these ideas to others in a form that is easily understood. Most often the communications tool is graphics. |
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| 2.1 Design is used for two primary purposes: personal expression, and product or process development. |
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| 2.2 Design for personal expression, usually associated with art, is divided into concrete (realistic) and abstract design and is often a source of beauty and interest. |
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| 2.3 When a design serves some useful purpose, such as the shape of a new automobile wheel, it is classified as a design for product or process development. |
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| 2.4-5 Aesthetic design is concerned with the look and feel of a product. Functional design is concerned with the function of a product or process. Function means that a product possesses a form related directly to the purpose of that product. Form is the overall physical appearance of a product and consists of many elements, the arrangement of which is critical to the aesthetics and function of the product. These elements are: Unity is the use of similar elements throughout the design or product line. The engineer accomplishes unity by thinking of the product as a whole instead of as individual parts or components. Style is the addition of decoration to a product and is closely linked to marketing. Line is another characteristic of a product. Space is the relationship of a product to its background, as well as to its negative elements (holes, slots, voids). Mass is the design element that provides a sense of weight or heaviness. Proportion is the relationship of the smaller elements to the whole design. Balance is the design element that gives the product equilibrium. Contrast is the feature used to emphasize or de-emphasize certain elements in a design. Color is the element used to evoke emotions, give sensations of weight, and enhance a design form. |
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| ENGINEERING DESIGN Engineering design is a problem-solving process that uses knowledge, resources, and existing products to create new goods and processes. Engineering design has both aesthetic and functional elements and can be broken into two broad categories: product design and system design. Product design is the process used to create new products, such as a new automobile model, a new appliance, and a new type of wheelchair. Product design is a complex activity that includes market, production, sales, service, function, and profit analyses used to product a product that meets the wants and needs of the consumer, is economically produced, is safe for the consumer and the environment, and is profitable to the company. System design is the process used to create a new system or process. A system is an orderly arrangement of parts that are combined to serve one general function. Examples of the system designs are: the arrangement of the assembly process in a factory; the heating, ventilation, and air-conditioning (HVAC) system in a structure; and the electrical system in the automobile. |
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| 2.6 Engineering design is one of the processes normally associated with the entire business or enterprise, from receipt of the order or product idea, to maintenance of the product, and all stages in between. An engineering design involves both a process and a product. A process is a series of continuous actions ending in a particular result. A product is anything produced as a result of some process. Graphics is an extremely important part of the engineering design process, which uses graphics as a tool to visualize possible solutions and to document the design for communications purposes. Traditional engineering design is a linear approach divided into a number of steps. For example, a six-step process might be divided into: problem identification, preliminary ideas, refinement, analysis, documentation, and implementation. The design process moves through each step in a sequential manner; however, if problems are encountered, the process may return to a previous step. This repetitive action is called iteration or looping. |
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| IDEATION Concurrent engineering is a linear team approach to design that brings together the input, processes, and output elements necessary to produce a product. |
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| 2.7 The concurrent engineering model shows how every area in an enterprise is related, and the CAD database is the common thread of information between each area. |
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| 2.8-9 The engineering design process consists of three overlapping areas: ideation, refinement, and implementation which all share the same CAD database. |
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| 2.10 Current engineering design practices make use of a number of new practices, including EDM/PDM, Intranets and Extranets, e-Business, and the Digital Enterprise. |
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| SUMMARY This chapter introduces you to modern design practices. Graphics have been and will continue to be an important part of engineering design. Graphics, in all forms, are the communications medium of choice in the design process. The use of computers to model the design and create a graphics database that can be shared by everyone on the team will even further enhance the role of graphics in the future. The engineer and technologist must know how to use graphics to communicate, visualize, and present technical information efficiently and effectively. |