上海交通大学：《Design & Manufacturing II and Project》课程教学资源（讲义）Lecture 1 Introduction to Design

上降充通大￥ Shanghai Jiao Tong University Mechanical Design and Manufacturing ll Introduction to Design 1

1 Mechanical Design and Manufacturing II Introduction to Design

上游充通大学 Shanghai Jiao Tong University Introduction Exercise Get in groups of 3 to 4 students and do the following: Make the longest list you can of people who design things for a living(like architect, fashion designer,etc.) >What do these people have in common and what is different? >Formulate a definition for“Design

2 Introduction Exercise Get in groups of 3 to 4 students and do the following: ¾ Make the longest list you can of people who design things for a living( like architect, fashion designer, etc.) ¾ What do these people have in common and what is different? ¾ Formulate a definition for “Design

上席充通大学 Shanghai Jiao Tong University Engineering Design Design: ·Comes from Latin word designare meaning to designate,or mark out Webster to outline,plot or plan as action or work...to conceive,invent, contrive. Design is the process of problem solving. Engineering Design: Process of applying various techniques and scientific principles for defining a useful device,process or a system in sufficient detail to permit it's realization. 3

3 Engineering Design Design: • Comes from Latin word designare meaning to designate, or mark out • Webster - to outline, plot or plan as action or work ... to conceive, invent, contrive. • Design is the process of problem solving. Engineering Design: Process of applying various techniques and scientific principles for defining a useful device, process or a system in sufficient detail to permit it’s realization

上浒充通大学 Shanghai Jiao Tong University Engineering Design Machine Design: Creation of machinery that works functionally, safely,reliably and well. >A machine is: an apparatus consisting of interrelated units a device that modifies force or motion "It is engineer's task to define and calculate the motions,forces,and changes in energy in order to determine sizes,shapes and materials needed for each of the interrelated parts in the machine."1 4

4 Engineering Design Machine Design: ¾ Creation of machinery that works functionally, safely, reliably and well. ¾ A machine is: ⁻ an apparatus consisting of interrelated units ⁻ a device that modifies force or motion “It is engineer’s task to define and calculate the motions, forces, and changes in energy in order to determine sizes, shapes and materials needed for each of the interrelated parts in the machine. ” 1

上充通大￥ Shanghai Jiao Tong University Engineering Design Broad Breakdown of Design Process: >Synthesis(综合) >Analysis(分析) > Iteration(反复) Successful solution of design problems will require engineer to develop a combination of skills in both synthesis and analysis. 5

5 Engineering Design Broad Breakdown of Design Process: ¾ Synthesis（综合） ¾ Analysis（分析） ¾ Iteration（反复） Successful solution of design problems will require engineer to develop a combination of skills in both synthesis and analysis

上浒充通大学 Shanghai Jiao Tong University Synthesis2 Synthesis >The qualitative or "creative"aspect of design >Involves the ab initio formulation of concepts that address the problem statement. >Several design concepts are sketched out and compared before making a decision. 6

6 Synthesis2 •Synthesis ¾The qualitative or “creative” aspect of design ¾Involves the ab initio formulation of concepts that address the problem statement. ¾Several design concepts are sketched out and compared before making a decision

上浒充通大学 Shanghai Jiao Tong University Analysis2 .Analysis >The quantitative component of design >Involves assigning numerical values to various design parameters and assessing resulting performance. >Performance may also be optimized with respect to design parameters (but it can never exceed limits inherent to the chosen concept). 7

7 Analysis2 •Analysis ¾The quantitative component of design ¾Involves assigning numerical values to various design parameters and assessing resulting performance. ¾Performance may also be optimized with respect to design parameters (but it can never exceed limits inherent to the chosen concept)

上洋充通大学 Shanghai Jiao Tong University Iteration2 .Iteration >Between synthesis and analysis may be desirable or even mandatory. >For example,chosen concept may not fulfill design stipulations for "reasonable"values of the design parameters; >or analysis could suggest an advantageous modification of design concept.Guided redesign. >While synthesis is (to some)the "glamorous"aspect of design,real -world engineering design is more often based on modification of existing designs or selection of standard components (gears,bearings,fasteners,etc. than on radically innovative concepts. 8

8 Iteration2 •Iteration ¾ Between synthesis and analysis may be desirable or even mandatory. ¾ For example, chosen concept may not fulfill design stipulations for “reasonable” values of the design parameters; ¾ or analysis could suggest an advantageous modification of design concept. Guided redesign. ¾ While synthesis is (to some) the “glamorous” aspect of design, real -world engineering design is more often based on modification of existing designs or selection of standard components (gears, bearings, fasteners, etc.) than on radically innovative concepts

上浒充通大学 Shanghai Jiao Tong University Engineering Design Detailed Design Process: Identification of need >Background research >Goal statement >Performance specification >Ideation and invention >Analysis >Selection >Detailed design >Prototyping and testing >Production 9

9 Engineering Design • Detailed Design Process: ¾Identification of need ¾Background research ¾Goal statement ¾Performance specification ¾Ideation and invention ¾Analysis ¾Selection ¾Detailed design ¾Prototyping and testing ¾Production

上浒克通大学 Shanghai Jiao Tong University Engineering Design-Identification of Need This is where a need is indicated.May be >Order from boss or client >Personal need >Desire to get into business Problem statement might be: >We need a better lawn mower 10

10 Engineering Design – Identification of Need • This is where a need is indicated. May be ¾Order from boss or client ¾Personal need ¾Desire to get into business • Problem statement might be: ¾We need a better lawn mower