lecture #13 erdm prof.johnw.sutherland feb. 9, 2004pages.mtu.edu/~jwsuther/erdm/lect13.pdfb a c 4 a...

Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland

Lecture #13

ERDM

Prof. John W. Sutherland

Feb. 9, 2004


The Product Design Process

• Concept Design - System Design

• Module definition - Assemblies

• Detailed Product Design - Material Type & Features

• Detailed Product Design - Dimensions & Tolerances

• Prototyping and Testing


So far....

• Want to understand how the characteristics of aproduct design impact the environment

- Material selection issuesMining & Metals processing, Plastics

- Concept designQFD proposed as one way to “hear the voices”:customer and environment

Next: How does product design geometry influencerecycling?


Product Life Cycle

ProductReuse

Remanufacturing

Recycling

Nature

MaterialDisposalRaw Materials/

Energy Acquisition

MaterialRefinement

ProductCreation

Product Usage

ProductDisposal


Reuse?

• What promotes it?

• What discourages it?


Remanufacturing?




Recycling?




Geometric Features

Focus on a single part (element of a larger product)

• Holes

• Slots

• Threads

• Contours

In general, the size and shape of a product.How do these features influence the three R’s??


Role of Geometric Features

• Large parts vs. small parts

• Large surface area vs. small

• Complex vs. simple

• Presence of mating / sliding surfaces

• Sections / features that experience high stress


Product Features

Hole

Chamfer

Bore

Slot

Boss

Bend

Groove Threads


Opitz Classification Code

LD

LD

LD

LD

LD

< 0.5

> 3

< 2

0.5 < < 3

WithDeviation

> 2 WithDeviation

Specific

Specific

0

1

2

3

4

5

6

7

8

9

Rot

atio

nalC

ompo

nent

s

AB

AC

< 3, > 4

AB

< 3

AB

AC

< 3, < 4

External Shape,external shape

elements

Internal Shape,internal shape

elements

PlaneSurface

Machining

Auxiliary holesand

Gear Teeth

OverallShape

OverallShape

OverallShape

OverallShape

RotationalMachining

Internal andExternal Shape

Elements

PlaneSurface

Machining

PlaneSurface

Machining

PrincipalBores

Auxiliary holes,Gear teeth,Forming

Auxiliary holes,Gear teeth,Forming

Dim

ensi

onM

ater

ial

Initi

atio

nof

Raw

Mat

eria

lsA

ccur

acy

1st DigitComponent

Class

2nd DigitOverall or

Main Shape

3rd DigitRotational

SurfaceMachining

4th DigitPlane

SurfaceMachining

5th DigitAuxiliary holes

Gear TeethForming

1st 2nd 3rd 4thDigit

Non

-rot

atio

nalC

omp.


MDSI Code (Manf. Data Sys., Inc.)


D-Class CodeStr. Cylder (A,B)

Cont. Tapered (C)Changing

Round O.D.Curved/

Spherical (D)

w/ straight (E)Combo

w/o straight (F)Solid

ShapesGearlike (G)

Round w/devations Reg. Dev. (H)

Irreg. Dev. (J)Rotational

Roundw/ bent

centerline (K)Drawn/

Basic Spun (L)Shape

Column Str. (M)

Non- Sheet Form (N)Rotational

Box-Like (P)

Unnamed (Q-Z)


Post-use Alternatives

Original Part

New Parts New Part

Excess Excess

New Part

Original Part

New Part

New PartsExcess

xcess

Excess

Excess

Excess


Washing MachinePercentage

DCLASS of TotalWashing Machine Category PartsPart Distribution

Str. Cylder (A,B) 26.38%26.38%

Cont. Tapered (C) 1.97%Changing

Round O.D.

31.10% 3.15% Curved/Spherical (D) 1.18%

w/ straight (E) 1.57%Combo1.57% w/o straight (F) 0%

SolidShapes61.41% Gearlike (G) 1.18%

Round w/devations Reg. Dev. (H) 18.11%

19.29%Irreg. Dev. (J) 0%

Rotational61.41% Round

w/ bentcenterline (K) 11.02%

Drawn/ 11.02%Basic Spun (L) 0%Shape 0%100%

Column Str. (M) 2.76%

Non- Sheet Form (N) 18.11%Rotational

38.59% Box-Like (P) 9.06%

Unnamed (Q-Z) 8.66%


RPI - Reprocessability IndexSystem (Wentland)

Focus on Rotational Parts

ProductNumber of

PartsRotational

Parts %

Washing Mach. 254 61%Cordless Drill 53 60%Automotive Jack 122 80%Electric Drill 79 68%Utility Engine 188 68%


RPI Philosophy

Define metrics that, when small, are more likely resultin product post-use. Metrics for the following

• Part complexity (more complex is bad)

• Part size (smaller parts are bad)

• Removable features (preferred)

• Relative stress level (low stress -- less damage?)

• Amount of mating (moving) contact areas (minimize)


Definition of RPI Terms

R1Volume of Bounding Volume

Part Volume-----------------------------------------------------------------------

VBVV

-----------= =

Projected Volume

Part


RPI Terms - 2R2

Surface AreaSurface Area of Bounding Volume------------------------------------------------------------------------------------ SA

SABV--------------= =


RPI Terms - 3

4 other terms to consider other factors

Want to minimize RPI

RPI calculation linked to AutoCAD

RPI Ri∑=


D-Class Parts


Washing Machine Parts


Washing Machine Parts - 2


Another Example

lecture #13 erdm prof.johnw.sutherland feb. 9, 2004pages.mtu.edu/~jwsuther/erdm/lect13.pdfb a c 4 a...

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