Chapter 2 Design Tools

Introduction Engineering Tools and Skills: –Design processes –Brainstorming –Sketching –Modeling –Analysis tools –Presentation and communication tools

Design Process The design process is a systematic problem-solving method for generating and developing ideas into solutions. The 12-step design process serves as a problem-solving approach and guide.

Design Process Step 1: Define the Problem Design brief: a concise information tool that summarizes the most important information about a design project. See Figure 2-4: Typical Design Brief.

Design Process Step 1: Define the Problem (cont.) Problem statement: written to clearly and concisely identify a client’s problem, need, or want. Design statement: describes what a design solution should do without describing how to solve the problem.

Design Process Step 2: Brainstorm Brainstorming: any technique that is used by a design team to generate ideas. –Openly discuss the problem –Identify existing knowledge –Generate questions to be answered –Define areas of focus for research

Design Process Step 3: Research and Generate Ideas Research: systematic study of materials and sources in order to establish facts and reach new conclusions. Engineer’s notebook: a journal that serves as a record of engineering research and a repository for solution ideas that are generated throughout a design process.

Design Process Step 4: Identify Criteria and Constraints Criteria: specific standards against which a design will be judged acceptable or unacceptable. Constraint: a general limit that is imposed on a design project such as a project deadline, a budget, materials, or manufacturing processes.

Design Process Step 5: Explore Possibilities Return to the initial solution ideas and sketches that were recorded in the engineer’s notebook during steps 2 and 3 and build from them. Goal is to generate a mass of sketches to identify the most promising ideas for more detailed exploration.

Design Process Step 6: Select an Approach Decision matrix: chart used by designers to quantify their opinions of two or more design ideas by assessing each idea according to a series of important considerations (see Figure 2-7).

Design Process Step 7: Develop a Design Proposal Design Proposal: –CAD part models and assemblies –Assembly drawings –Dimensioned multiview drawings of each manufactured component

Design Process Step 7: Develop a Design Proposal (cont.) The goal of a design proposal is to document the solution to the degree that a competent manufacturer could build a prototype without the need for further clarification on the part of the design team.

Design Process Step 8: Model or Prototype Model: detailed three-dimensional representation of a design that is used to communicate, explore, or test an idea. Prototype: one-of-a-kind working model of a solution that is developed for testing purposes.

Design Process Step 9: Test and Evaluate Involves the client working with the engineering design team to determine what tests will be used to measure the quality of the design solution. Data must be recorded, organized, and analyzed.

Design Process Step 10: Refine Refine any issues or shortcomings that are identified through testing and analysis. Ideas for changes to the design should be sketched out in an engineer’s notebook and accompanied by explanations.

Design Process Step 11: Create the Final Solution The design statement will identify whether the final solution is a: –Custom (one-of-a-kind) design. –Limited-production item. –Mass-produced product.

Design Process Step 12: Communicate the Results Technical report Digital presentation Demonstration of the actual working solution

Design Process Brainstorming: –Allows team members to think creatively without judgments or constraints –Can be done in groups or as individuals –Involves five to seven individuals who have diverse backgrounds –Groups often have a facilitator

Design Process Other Methods of Brainstorming: –Stepladder –Reverse-brainstorming process

Sketching Sketch: rough drawing that shows the main features of an object or scene. Pictorial: gives the illusion of 3-dimensions by showing an object’s height, width, and depth in a single view. Multiview: portrays an object as a series of two or more 2-dimensional views arranged in a specific pattern.

Figure 2-12: Pictorial Sketch. Sketching Figure 2-12: Pictorial Sketch. © Cengage Learning 2012

Modeling Ideas Computer-aided design (CAD) software helps engineers in many industries design and manufacture products. CAD models resemble the final product to a degree of geometric precision that is beyond that of a physical prototype.

Modeling Ideas Finite element analysis (FEA): computer-based design analysis tool that allows the user to apply virtual forces and pressures to a 3-D CAD model. Computer-aided manufacturing (CAM): software that creates machine tool control programs.

Modeling Ideas Rapid prototyping (RP): collection of CAD data-driven physical model construction technologies that utilize additive manufacturing processes. Types of RP: stereolithography (SLA); fused deposition modeling (FDM); selective laser sintering (SLS); powder-binder printing.

Analysis Procedure Step 1: State the problem Step 2: Create a diagram Step 3: Make assumptions Step 4: Choose equations Step 5: Calculations Step 6: Check solution Step 7: Discuss results

Presentation Tools Digital Presentations: –Microsoft PowerPoint: slide show should be eye-catching, well-organized, and informative. Public Speaking

Figure 2-24: The Do’s and Don’ts of Public Speaking. Presentation Tools Do Don’t speak normally and with enthusiasm. project your voice; if necessary use a microphone. speak clearly. repeat key points and emphasize them with deliberate pauses. keep your eyes on the audience. admit when you don’t know the answer to a question, and convey a sincere desire to find and return an answer. speak too fast or too slowly. turn your back to the audience. hide behind the lectern. read directly from the slides or your notes. apologize if you can’t answer a question but admit that you don’t know the answer and that you will try to find out and get back to the questioner. Figure 2-24: The Do’s and Don’ts of Public Speaking.

Summary Engineers use the 12-step design process method to solve problems. Brainstorming combines individual brain power with human interaction to generate ideas for solving a design problem.

Summary Sketching is a form of visual communication. Engineers use computer-aided design (CAD) programs. There are 7 steps in the systematic analysis procedure. Digital presentations are the final step of the design process.