Dec 31, 2015

Axiomatic Design Theory. What is axiom? is known to be true by understanding its meaning without proof. a starting point for deducing and inferring other (theory dependent) truths. - PowerPoint PPT Presentation

Welcome message from author

This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript

1

Axiomatic Design Theory

What is axiom?– is known to be true by understanding its

meaning without proof. – a starting point for deducing and inferring

other (theory dependent) truths.

Axiomatic design theory: it is a design theory that has been verified by numerous applications. In other words, it is true (starting point) and accepted by engineers without proof.

2

Axiomatic Design Theory

Axiom 1: Independence Axiom

Axiom 2: Information Content

3

Axiomatic Design Theory(Axiom 1)

4

Axiom 1 – Design example

Hold hot water

Requirement:

hold hot (~100oC) water with hand

Grasp the holder

Hold water without consideration of

temperature

Resist heat conduction

5

Isolating material

Grasp the holder

Hold water without consideration of

temperature

Resist heat conduction

DPDP

DP

6

Axiom 1

The better design meets:

Design or function requirement (FR) should be independent or uncoupled on their own right

Design parameters (DP) should maintain the FR independent – i.e., not making FR coupled

7

2

1

220

011

2

1

DP

DP

A

A

FR

FR

8

2

1

2221

1211

2

1

DP

DP

AA

AA

FR

FR

2

1

2221

11

2

1

DP

DP

AA

A

FR

FR

2

1

22

11

2

1

DP

DP

A

A

FR

FRUncoupled

Coupled

Decoupled

To satisfy the independence axiom, the design matrix must be either diagonal or triangular

(Diagonal matrix)

(Full matrix)

(Triangular matrix)

9

Example – Axiom 1

Hinge

FR1=Provide access to items stored in the refrigerator

FR2=Minimize energy loss

10

Hinge

FR1=Provide access to items stored in the refrigerator

FR2=Minimize energy loss

S1=Vertically hung door

S2=Thermal insulation material in the door

S1’=Horizontally hung door

11

2

1

2221

11

2

1

DP

DP

AA

A

FR

FR

Hinge

2

1

22

11

2

1

DP

DP

A

A

FR

FR

Decoupled Uncoupled

The cold air stays inside when the door is opened

12

12 FRs:Contain axial pressure,Withstand a moderate impact when the can is dropped,Provide easy access to liquid, etc.

Physical pieces: Just 3(the body, the lid, the opener tab)

DPs: 12 The thickness of the can bodyThe curvature at the bottom of the can etc.

Axiom 1 is focusing upon Functional independence but not physical independence

13

Physical integrationPhysical integration

Notion: logical and physical

OneFR1/DP1

FR2/DP2

FR and DP in ADT refer to the logical level

14

Solution principle 1 for opening type 1 of lid At the conceptual design phase

Solution principle 2 for opening type 2 of lid At the conceptual design phase

The geometry of each of them refers to the embodiment design phase

Their relationship (distance, material interface) refers to the embodiment design phase

15

Decoupled DesignDecoupled Design

2

1

2221

1211

2

1

DP

DP

AA

AA

FR

FR

2

1

2221

11

2

1

DP

DP

AA

A

FR

FR

2221212

1111

DPADPAFR

DPAFR

16

Decoupled DesignDecoupled Design

2221212

1111

DPADPAFR

DPAFR

Step 1: Change DP1 to affect FR1 and FR2

Step 2: Change DP2 to affect FR2

Step 1 has also affected FR2 but in Step 2, this effect is changed back and to further affected by DP2 only

17

Axiom 1 revision

The better design meets:

Design or function requirement (FR) should be independent or uncoupled on their own right

Design parameters (DP) should maintain the FR independent – i.e., not making FR coupled

Remark: In the recent development, decoupled situation of FR will also be considered in Axiom 1, i.e., acceptable as a better design.

18

3

2

1

232221

131211

2

1

DP

DP

DP

AAA

AAA

FR

FR

Redundant design

2

1

2221

1211

2

1

DP

DP

AA

AA

FR

FR

19

Redundant designRedundant design

2222

3131111

DPAFR

DPADPAFR

3

2

1

232221

131211

2

1

DP

DP

DP

AAA

AAA

FR

FR

20

SummarySummary

1. Axiom 1 of ADT concerns coupling, decoupling, and uncoupling among functional requirements both in direct and indirect (through DP) manners.

2. Axiom 1 suggests the better design to be uncoupled or decoupled.

3. Logical design versus physical design.

4. Physical design refers to embodiment design.

5. Axiom 1 of ADT is only applicable to the conceptual design.

21

SummarySummary

6. Redundant design concept: more DP than FR.

7. It is a relative concept about coupling, decoupling and uncoupling.

Related Documents