Review for Exam #1

ISE316Fall 2010

Readings

• Chapter 1 -- What is manufacturing?• Chapter 2 -- The nature of materials• Chapter 3 -- Mechanics of materials• Chapter 2 and 3 of supplement --

Dimensioning and tolerancing• Chapter 21 – Theory of machining• Chapter 22 – Fundamentals of machining

Chapter 1 -- What is manufacturing?

• Importance of manufacturing

IE 316 Manufacturing Engineering I - Processes

Manufacturing Is Important Economically

Manufacturing is a means by which a nation creates material wealth

• In the U.S. manufacturing constitutes ~ 20% of GNP

• Government is as much of GNP as manufacturing, but it creates no wealth

U.S. economy:

Sector% of GNP

Manufacturing 20%

Agriculture, minerals, etc. 5%

Construction & utilities 5%

Service – retail, transportation, banking, communication, education, and government

70%

IE 316 Manufacturing Engineering I - Processes

Manufacturing is Important Historically

• Historically,word “manufacture” was first coined around 1567 A.D.

• Most modern manufacturing is accomplished by automated and computer controlled machinery that is ‑manually supervised

IE 316 Manufacturing Engineering I - Processes

Manufacturing is the application of physical and chemical processes to alter the geometry, properties, and/or appearance of a given starting material to make parts or products; manufacturing also includes assembly of multiple parts to make products

• Manufacturing is almost always carried out as a sequence of operations

Figure 1.1 (a) Manufacturing as a technical process

Traditional Engineering

Engineering

Mechanics of Materials

Fundamentals of Mechanics

ISE 316 - Manufacturing Processes Engineering

Figure 3.2 Typical progress of a tensile test: (1) beginning of test, no load; ‑(2) uniform elongation and reduction of cross sectional area; (3) ‑

continued elongation, maximum load reached; (4) necking begins, load begins to decrease; and (5) fracture. If pieces are put back together as in

(6), final length can be measured

ISE 316 - Manufacturing Processes Engineering

Engineering Stress

Defined as force divided by original area:

oe A

F

where e = engineering stress, F = applied force, and Ao = original area of test specimen

ISE 316 - Manufacturing Processes Engineering

Engineering Strain

Defined at any point in the test as

where e = engineering strain; L = length at any point during elongation; and Lo = original gage length

o

o

LLL

e

ISE 316 - Manufacturing Processes Engineering

Figure 3.3 Typical engineering stress strain plot ‑ ‑in a tensile test of a metal

ISE 316 - Manufacturing Processes Engineering

Two Regions of Stress Strain Curve‑

• The two regions indicate two distinct forms of behavior: 1. Elastic region – prior to yielding of the material2. Plastic region – after yielding of the material

Dimensioning and tolerancing

• Traditional dimensional specification– Datums– Tolerance stacking

• ASME Y14.5 standards– Form geometry– Material conditions

• Inspection

Machining

• Principles of metal cutting• Basic geometry of cutting

– Chip formation– Shear– MRR

• Turning/lathe operations– Cutting geometries– Time

• Milling and drilling• Principles of process planning

ISE316

Test #2 review

Chapters covered

• Chapter 23 – Tool technology and tool life• Chapter 24 -- Machining economics• Chapter 19 – Metal Forming• Chapter 20 – Sheet metal working

Exam format

• Chapters 23 and 24 will be covered on Tuesday November 16

• Chapters 19 and 20 will be covered on Thursday November 18

Let’s play ISE316 Jeopardy/Jeopardy -1

Topic – Tool technology

• He developed the first tool life equation• Who is Fredrick Taylor?

Topic – Tool technology

• Primary independent variable/parameter for tool life

• What is cutting velocity?

Topic – Machining economics

• T/Tm in the machine economics equation• What is the fraction of the tool used in a single

operation?

Topic – Metal forming

• This process produces steel plate and sheet above recrystalization temperature

• What is Hot working

Topic – Metal forming

• The process used to produce the structure frame pieces for aluminum screen doors

• What is extrusion?

Team Jeopardy-1

• In this portion of the review a question will be asked to the entire team. When the team has the answer, they will chime in to be recognized first with the answer and then the method used to get the answer.

Topic – Tool technology

• In a turning process where a 2” diameter bar is turned to 1.75”, find the following– Depth of cut

• For the processing, each part is 6 inches long and turned for half the part length and then cut off at the 6 inch mark and then collected via a conveyor in the bed of the lathe.– How long does the turning operation take if the velocity is 300

fpm and the feed is .008 in/rev?• The cut off operation occurs with a velocity of 250 fpm

and a feed rate of 5 ipm.– How long does the cut off process take?

Topic – Tool technology

• For the turning operation previously described (V= 300 fpm, f = 0.008 ipr) the tool life realized for the process was 55 minutes. The operator changed the velocity to 400 fpm and the tool life changed to 35 minutes. What is the tool life equation for the tool?

Topic – Tool economics

• If the time required to change the tool is 5 minutes, what is the optimum velocity?

Topic – Machining economics

• If 500 parts are to be made in batches of 50, how expensive is the part? Cmo = $35/hr; Tl/ul = .1 min; Process engineering time for the part was 8 hours; engineering time is $150/hr; batch set-up time is 2 hours

Topic – Sheet metal working

• A 1.0 in wide 90o corner bracket made of 0.125 inch Cold Rolled steel is to be made in large quantities. The finished bracket will be 2 inches long on either side and will have 2 ¼ inch holes equally spaced on the flat surface.– How long should the blanks be cut?

Topic – Sheet metal working

• What tonnage press is required to make the brackets?

• What tooling is required?

And finally, …

• Nano-technology and nano-manufacturing – Chapters 36 and 37 from the book– Powerpoint slides