Engineering Assignment

EduPack 2012

Class Exercises

Exercises 1 -3 : Browsing and Searching

Exercise 4: Property Charts

Exercise 5:Using a Limit Stage

Exercise 6: Graph Selection

Exercise 7: Tree Selection

Exercises 8, 9: Getting it all Together

Exercise 10: Process Selection

Exercises 11, 12 : saving, Copying, Report Writing

Toolbars in EduPack

The Chart-Management Tool Bar

Line selection tool

Box selection tool

Cancel selection

Add text

Zoom Add

envelopes

Un-zoom

Black and white chart

Hide failed materials

Grey failed materials

Add grid

Exercise 13, 14

• What is Goretex made of?

• Find what the process SLS is all about by searching on SLS. Since it is a process, not a material, you will have to change the table in which you search from Materials Universe to Process Universe, in the box immediately below the search box.

Exercise 15, 16

• Find materials that cost less than $1/kg and are good electrical conductors. Enter the upper limit on price and the constraint that the material must be a good conductor. Then click APPLY at the top of the screen. The materials that do not meet the constraints are deleted from the RESULTS window on the lower left, leaving those that do meet the requirements.

(ductile CI, grey CI, high C steel, low alloy steel, low C steel, medium C steel) • The property Fracture toughness is a measure of how well a

material resists fracture. A brittle material like glass has a low value of fracture toughness – around 1 in the units you will use (MPa.m1/2) Steel used for armor has a very high value – over 100, in the same units. Many engineers, when designing with metals, avoid material with toughness less than 15. Use a Limit stage to find materials with Fracture toughness greater than 15 and that are good electrical insulators. (GFRP)

Exercise 17

• If you want to make a high quality cooking pan to go on the top of a gas stove, you need a material with a high thermal conductivity. The high conductivity is to spread the heat, preventing hot-spots where the flame hits the pan.

• The material must have enough elongation to be shaped to a pan (requiring elongation > 15%), and a maximum use temperature of at least 150 oC.

• First make a limit stage and put these (lower) limits on elongation and maximum use temperature. Then make a graph with thermal conductivity on the Y-axis. To do this first click on Select, then on New and then on Graph stage. Select the Y-axis tab and find Thermal conductivity in the Attribute list and double click to select it. When you click OK you get the graph shown above. To make the materials that fail the limits grey out, click on the little icon like two intersecting circles in the icon bar just above the graph. Use a box selection (the little box icon in the same icon bar) to select the materials with the highest thermal conductivities.

Exercise 18

• You want to make a casing for a mobile phone, exotic in color and design. It snaps onto the front of the phone, transforming it from a drab object to one of glamour. Research reveals that the shape is best made by Thermoforming (a very cheap process for shaping polymer sheet into dished and curved shapes) and that the decoration is best applied by In-mold decoration that can be done at the same time as the thermoforming. Find materials that can be processed in this way. To do this, make two Tree-selection stages. Select -> New -> Tree: Under the word Trees, half-way down the box, it says Material Universe. We want to impose constraints on Processes, so first click on the down-arrow and change the Tree to Process Universe. Open Shaping and find Molding – Thermoforming and double click to make it appear in the box above. The wizard window now looks like the one above (we have closed Shaping again for clarity). Click OK and the number of materials in the Results window drops to 18 – these are materials that can be thermoformed. Repeat the job with a second, new, Tree stage, this time opening Surface treatment and choosing Painting and Printing – In mold decorating. The results window now lists materials that can both be thermo-molded and in-mold decorated (10 materials).

Exercise 19

• Problem 1: Select material for bulb filament for an automobile headlight. • A headlight is an essential part of an automobile. Headlights differ in detail, but all

have a bulb containing a filament enclosed in a transparent envelope. The filament is exposed to harsh conditions: very high temperature, vibration and a risk of oxidation. The goal of the project is to use CES to select a material for the filament.

• Requirements: – Must be an electrical conductor – Must resist oxidation – Must have the highest possible melting point

• Procedure:

Exercise 20 • Problem 2: Select material for the lens of an automobile headlamp. Headlamp lens protects the bulb and reflector and focuses the light where it is most needed. The project is to use CES to select materials for the lens. • Requirements:

– Must be transparent with optical quality. – Must be able to be molded easily. – Must have very good resistance to fresh and salt water – Must have very good resistance to UV light – Good abrasion resistance, meaning a high hardness – Low cost Price (USD/kg)

• Procedure:

Exercise 21

• Problem 3: Select material for Disposable Cutlery. • If you eat at an expensive restaurant, the knives may have steel blades and ivory handles, and the

forks and spoons could be made of silver. But if you eat at a local fast food joint or on an airplane, the same function is fulfilled by disposable plastic cutlery. The function is unchanged; but the objectives, clearly, are different: minimizing cost and – you might hope – maximizing recyclability or renewability. Filling the function imposes constraints on material and shape: the plastic fork that snaps in half the first time you use it is only too familiar. Minimizing cost makes choice of process critical, and the material itself must also be cheap

• Requirements: – Young’s Modulus > 1.7 GPa – Tensile Strength > 24 MPa – Cost < $1.8/kg – Manufacturing process: economical for batch sizes >= 100,000 pieces – Recyclable – Bio-safe – Corrosion resistant – …

• Procedure: – Up to you now!

Physical Constants and Unit Conversion Tables

Exercise 22: Eco Audit

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Exercise 22: Eco Audit (contd.)

Exercise 23: Compare Eco Audits

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Class Exercise 24, 25: Saving Eco Audit Product Definition

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Summary: EduPack

By now you should feel comfortable with doing the following actions using CES EduPack materials engineering software

• Selecting appropriate databases (mainly Level 2) • Understand the structure of materials and processes databases

and their linkages with each other and with manufacturers and resources databases

• Browsing, searching, selecting • Using graph, limit and tree stages in selecting • Creating material property charts – bar charts and bubble charts • Conduct materials design projects • Conduct materials selection process • Conduct EcoAudit for a product • Saving, editing, importing and report writing