CHAPTER 1 Introduction to Graphics Communication

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CHAPTER 1 Introduction to Graphics Communication

Objectives AND OVERVIEW

After completing this chapter, you will be able to:

1. Describe why the use of graphics is an effective means of communicating when designing. pp. 2-7

2. Describe the engineering design process and the role graphics play. pp. 7-16

3. Describe the model-centered design process. pp. 10-11

4. Explain the role 3-D modeling plays in the engineering design process. p. 29

5. Describe the role of CM, PLM, and PDM in the engineering enterprise. p. 13

1. Describe the important types of graphics used to support the engineering design process. pp. 17-19

1. List and describe the modeling techniques used in design. p. 21

1. List and describe the analysis techniques used in design. p. 25

1. Describe additional technologies used to capture data, output, and visualize 3-D models. pp. 45-51

1.1 INTRODUCTION

Chapter 1 provides an introduction to the graphic language and tools of the engineer and technologist. This chapter reveals the role of technical drawing as an effective tool to:

• Communicate engineering concepts,
• Relate past developments to modern practices, and
• Examine current industry trends

This chapter covers the basic notions and the terminology required to understand technical drawing and offers an overview of the tools, underlying principles, standards, and conventions of engineering graphics. Next, this chapter introduces sketching and the use of sketching for lettering, which is covered in greater detail subsequently.

Graphics communication plays an inevitable role in engineering design. Engineering design involves several features that cannot be communicated verbally, but are rather “visual images in the mind” (of the designer). Technical graphics involves communicating such information in a nonverbal manner. A visual image is formed in the mind (of the designer), reviewed, modified, and ultimately communicated to another person, all using visual and graphics processes.

Sharing technical information graphically is becoming an important process for both engineers and technologists due to the involvement of nontechnical people in the design process. With the continued expansion of the “circle of people” requiring technical information, efficient tools such as computer graphics have become an inevitable part of the design process.

1.2 The importance of graphics in the design process

During the design process, technical graphics serves as an effective media for visualization, communication, and documentation. Graphical representations are used both for modifying 3-D objects from an initial design and also for creating such objects from scratch. Computer-based renderings of such models not only facilitate representing huge amounts of detail, but also help communicate the design among the people involved. However, current design processes are becoming inherently complex and entail complicated solutions. Hence, specialized knowledge is required to use the agreed-upon language (developed by standards organizations) of technical drawing and modeling.

Visualization, the process of envisioning things that do not exist, is the foremost step in the utilization of graphics for design. Communication involves refining the initial sketches from the earlier step and conveying them with clarity. Once the design solution is finalized, it needs to be documented before the actual process of creation can take place. Technical graphics plays a crucial role in all the three processes mentioned above.

1.3 The engiNEERING design process

Engineering design represents both the action (process) and the result (product). Engineering design relies heavily on graphics and uses graphics as a tool both to visualize potential solutions and to document the design for communication.

The use of innovative computer-based tools has allowed greater flexibility in information access and utilization. 3-D design tools such as CAD have facilitated the shift from the traditional linear approach to a model-centered, nonlinear approach wherein the input, processes, and output elements can be integrated at the very beginning. The engineering design process consists of three overlapping areas, namely ideation, refinement, and implementation, all of which share the same 3-D CAD database.

With the rise of the model-centered engineering paradigm, an enterprise-wide integrated product development process called collaborative engineering evolved. Collaborative engineering creates the infrastructure and the optimal environment for computer-based team collaboration for information storage and sharing. The tools include CAD, CAM, CAE, and office applications. Configuration management (CM) and product data management (PDM) software programs are used to manage long-term overall design/manufacture processes. Such software programs inherently incorporate Internet browser interfaces, which are essential for linking operations spanning multiple locations.

Manufacturing a new product entails the involvement and contributions of all of a company’s departments, and this simultaneous collaboration is made possible by a model called PLM (Product Lifecycle Management). PLM enables creating, managing, simulating, sharing, and communicating digitally all the information related to the company’s products, processes, and resources, optimizing its overall performance. Also, PLM is a strategic business approach for the effective management and use of corporate intellectual capital (CIC), which represents the sum of retained knowledge that an organization accumulates during the course of product delivery. PLM concurrently facilitates three deeply interrelated processes: supply chain collaboration, product development, and enterprise process integration.

The use of computers in the design process can facilitate good communication between members of the design team. By and large, the size of the design project determines the number and types of individuals that comprise the design team. Design projects are grouped as:

• Modification of an existing design
• Improvement of an existing design
• Development of a new product

1.4 ideation

Ideation, the conceptual phase in the design process, refers to the structured approach to thinking for the purpose of solving a problem. Problem identification is an ideation process in which the parameters of the design project are established before attempting to find a solution. Engineering design problems must be defined clearly before the design process can begin. Subsequent to problem identification, teams develop preliminary ideas for solving the problem, which is referred to as “brainstorming.” Brainstorming results in a list of ideas, along with some preliminary sketches or computer models. After brainstorming, the ideas are evaluated based on the problem statements, project goals, and limitations.

During the ideation phase, rough sketches and conceptual computer models called ideation drawings or models are produced. Ideation drawings communicate new ideas through the use of rough sketches and computer models. Ideation entails skills in sketching, visualization, and presentation graphics. The resources for ideation are numerous. Creative ideas can come from various sources, both from personal experience and outside sources. Designers should take meticulous notes to ensure that ideas and decisions are preserved for future reference. A very important reason for keeping notes is to make it easier to document original designs, which is imperative when applying for a patent.

1.5 refinement

Refinement, the second major step in the collaborative engineering design process, refers to the iterative process of testing the preliminary design, make required changes, and determining if the design meets the goals of the project. Refinement involves modeling, design analysis, and design visualization. The refinement stage is extremely dependent on graphics to document, visualize, analyze, and communicate the design idea. These drawings and computer models are called refinement drawings or design drawings.

The modeling stage involves representing abstract ideas, words, and forms through the orderly use of simplified text and images. Models are classified as descriptive or predictive models. A descriptive model presents abstract ideas, products, and processes in a recognizable form. A predictive model is used to understand the behavior/performance of ideas, products, or processes. During the refinement process, two types of models, mathematical models and scale models, are employed. The former type employs mathematical equations to represent system components, while the latter refers to the physical model created to represent system components. Models serve as extremely useful tools for engineers for thinking, visualizing, communicating, predicting, controlling, and training. Computer simulation and animation are two important terms that need to be covered in this context. Computer simulation is the precise modeling of complex situations involving a time element. Computer animation is the imprecise modeling of complex situations involving a time element. While an animation only approximately replicates a real situation, a simulation exactly replicates a real situation.

1.6 design review meetings

A design review is a formal meeting where the design team explains the progress made to the administration. Presentations involving calculations, charts, graphs, sketches, technical graphics, and 3-D models are made by the design team to describe the progress to the management. The ultimate purpose of the meeting is to determine if the design of the product should continue or cease.

1.7 implementation

Implementation is the final phase in collaborative engineering design wherein the final design is transformed from an idea into a product, process, or structure. The implementation process involves making the design solution a reality for the enterprise and the consumer.

Implementation includes planning, production, financing, marketing, service, and documentation. The planning process is used to determine the most effective means to steer the product through the production cycle. Simply stated, production involves transforming raw materials into finished products. Marketing is the process of anticipating customer needs and directing the flow from the producer to the consumer. The finance process analyzes the financial viability of the product manufacturing process. Management entails logically organizing manpower, materials, energy, equipment, and procedures to produce the desired outcome (product).

The final phase of development after finalizing the design using the refinement process is called documentation, which refers to the formal recording and communication of the final design solution. Concurrent documentation refers to the simultaneous creation of the documents while the product is being developed. Technical illustrations are developed and employed all through the concurrent engineering and documentation process, starting with the design database. Animations are also employed in the documentation phase to facilitate marketing, training, production, and service activities. Animations are used in marketing for purposes of advertisement. Technical reports are extremely detailed accounts of the design process, which include both text and graphics.

1.8 product data control

The effective management of all product-related information constitutes a crucial aspect of the design process. The term product data management (PDM) refers to the specific computer-based tools and processes used to manage this information. PDM software is used to track CAD and other documents with user-defined data fields, and information stored in one file is linked to other business modules/systems within the enterprise. The system that especially focuses on the ordering of material and planning for the materials used in product manufacturing is called enterprise resource planning (ERP).

1.9 other engineering design methods

A technique called design for manufacturability (DFM) is used to manufacture reliable products with fewer parts, which can be assembled in a time-saving and economical manner. DFM focuses on simplicity in manufacturing and functionality. Knowledge-based engineering (KBE) refers to the system that complements CAD, adding the engineering knowledge needed for designing a product. This KBE system is programmed by defining the rules or engineering criteria for the design.

1.10 standards and conventions

An agreed-upon standard of signs and symbols is absolutely inevitable for effective communication. The graphics language must follow aset of standards and conventions for effective and clear communication involving technical graphics. Conventions refer to commonly accepted practices, rules, and methods. Standards are the sets of rules that govern how technical drawings are represented.

1.11 graphic communication technologies

Similar to the evolution of the graphics language over the years, with advancements in technology, the tools used for graphically communicating technical ideas have also undergone considerable evolution over time. These tools have evolved from traditional paper-and-pencil-based tools to sophisticated computer-aided design/drafting (CAD) systems. CAD refers to the computer software and hardware that supplements or replaces traditional hand tools in creating models and technical drawings. Reverse engineering is the method of taking an existing product, accurately evaluating it, and putting the information into a CAD database. The output devices used to make hard copies of the drawings created on screen are categorized as printers, plotters, or film recorders. Storage devices are also used to facilitate information storage, retrieval, and sharing.

In the context of the current discussion, one important term that is being used quite frequently in engineering design is virtual reality (VR). VR presents an illusion of reality by deceiving the human senses. VR captures the user’s multiple senses through computer-based and other artificial means to make the user believe something is real, when it is actually not. The use of VR in the industry has shown great potential and is being increasingly employed in engineering design and scientific visualization.

1.12 summary

The following six primary areas were covered in this chapter:

• Visualization
• Graphics Theory
• Standards
• Conventions
• Tools
• Applications

Graphic communication is akin to communicating in a language. Learning graphic communication is similar to the process of learning a new language, in the sense that a set of rules need to be followed for effective and clear communication. Technical graphics is a very effective tool that supports the design process.

Goals review

1. Describe why the use of graphics is an effective means of communicating when designing. Section 1.2

2. Describe the engineering design process and the role graphics play. Section 1.3

1. Describe the model-centered design process. Section 1.3.2

1. Explain the role 3-D modeling plays in the engineering design process. Section 1.3

1. Describe the role of CM, PLM, and PDM in the engineering enterprise. Sections 1.3.7 through 1.3.9 and 1.8

1. Describe the important types of graphics used to support the engineering design process. Sections 1.4 through 1.6

1. List and describe the modeling techniques used in design. Section 1.5

1. List and describe the analysis techniques used in design. Section 1.5.3

1. Describe additional technologies used to capture data, output, and visualize 3-D models. Section 1.11

Questions for Review

1. Explain the difference between engineers and technologists.

A drawing is a graphical representation of objects and structures and can be done freehand, with instruments or on the computer. Engineering and technical drawings are specialized drawings. p5-6

2. How can visualizing help an engineer in the design process?

Ideation drawings are used early in the design process to explore design alternatives. p6, 8

3. What are the three main areas or phases of the model-centered design process? Do the activities in these areas happen in a sequential fashion?

Document drawings are used at the end of the design process to record the final design. p8

4. Explain how PLM is used in the design process. What is its relationship to CIC?

They provide a clear, robust method of communicating complex technical information which often can't be conveyed by any other means. p5

1. Outline the steps of problem identification in the ideation phase.

1. What kinds of graphics are used in the ideation phase?

1. What is the designer’s notebook? How is it used?

1. Outline the main activities in the refinement phase.

1. Describe the different kinds of models used in the design process.

1. Describe the different kinds of analysis techniques used in the design process.

1. Outline three ways the 3-D model database can be used in the implementation phase.

1. What kinds of documentation might be produced as part of the design process?

1. Explain the role of PDM in the design process. What is the relationship between ERP and PDM?

1. What is the difference between conventions and standards?

1. Describe two reverse engineering techniques.

1. Describe two different rapid prototyping technologies.

1. Explain why an enterprise might want to store data in an off-site data warehouse.

1. Describe two different VR display techniques.

Answers to Review Questions Chapter 1

1. Explain the difference between engineers and technologists.

Engineers are creative (usually formally educated) people who use technical means to solve problems. They design products, systems, devices, and structures to improve our living conditions. Technologists work with and for engineers and are concerned with the practical aspects of engineering in planning and production. p. 3

2. How can visualizing help an engineer in the design process?

Visualizing allows design engineers to mentally picture things in their minds that do not exist. Additionally, good visualization skills allow them to visualize motion, change the form or shape, and move around and picture the inside of the mental image of the design problem. p. 6

3. What are the three main areas or phases of the model-centered design process? Do the activities in these areas happen in a sequential fashion?

The three main areas or phases of the model-centered design process are ideation, refinement, and implementation. Model-centered engineering design is a nonlinear team approach to design that brings together the input, processes, and output elements necessary to produce a product. pp. 10-11

4. Explain how PLM is used in the design process. What is its relationship to CIC?