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# Introduction

EG2502: Laboratory 2

In this laboratory session, we were given a list of exercise to work on CES Edu pack. The main objects of this lab was to focus improve our ability of solving some logical exercises (e.g. last question).

Question 1:

- the approximate range of elastic modulus for elastomers, what is meant by an elastomer;

First of all, we need to build up a graph by using “Graph” feature in “Select” section. For “y” axis we choose Mechanical property => Young’s modulus and press “Ok”. Then using “Tree” function , we choose: Polymers=>Elastomers and press Insert.

Result:

There are 8 elastomers that in range of from 0.001-0.1 GPa. (Can be seen on graph above)

- three cheapest metals with the density less than 9800 kg/m3;

Using knowledge from previous question we set up a graph with general properties price against density. Then using “tree” function we choose Metals and alloys and we’ll set up limit function by general property => density. The maximum density is 9800 kg/m^3. The results are shown on the graph.

- three most expensive electrical insulators;

As before, price graph was set and by limitation of good inulators 4 most expensive good insulators are picked.

- the approximate range of thermal conductivity for metals and technical ceramics.

Steps:

• Tree function is used to sort out metals and technical ceramics.

• The graph is setted on “Thermal conductivity”.

• Approximate range:10-1000;

Question 2:

Connectors like the parallel port of a PC allow several connections to be made simultaneously. The material specifications from the manufacturer are listed below:

electrical insulator;

service temperature > 100 0C;

tensile strength > 100 MPa;

Young’s modulus < 4GPa;

elongation > 2%;

able to be injection moulded.

In this question we need to sort out materials for port connection of PC. First of all, we use Edu level 2 Materials with durability properties. Then using limit, for electrical properties we tick for good insulator,for thermal properties we put maximum service temperature max: 100 C, mechanical properties: tensile strength min:100MPa, Young’s modulus max:4 GPa and elongation min: 2%. After that using tree property from process materials we insert: Shaping=>Molding.

Finally we set a graph for price and pick the coloured materials from graph.

Question 3:

L2.3.Headlights differ in detail, but almost all have a bulb containing a filament enclosed in a transparent envelope. The filament is exposed to harsh conditions: very high temperature (up to 850 0C) and a risk of oxidation. Find the appropriate materials for the filament with price consideration.

From "Select" function choose Edu Level 2: Material with durability properties. Using limit, for thermal properties put 850 C in minimum box of Maximum service temperature, then choose good conductor. Finally, to limit material with risk of oxidation, on Durability: thermal environments chooseTolorance up to 850 C and press apply. Make a graph, put on y axis price and pick up material with cheapest prices.

Question 4:

L2.4. The lens of an automobile headlamp protects the bulb and reflector and focuses the light where it is most needed. Find the appropriate materials for the lens if the material specifications from the manufacturer are listed below:

resistant to water and UV light;

abrasion resistant;

able to be injection moulded.

By using limit we set for optical properties transparency: optical quality. Then in column durability: water and aqueous solution we pick fresh water and salted water: acceptable and excellent. Additionally, setting up for built environment durability: resistible for UV lights we pick good and excellent and press apply. The limit may give us a range of materials, so to avoid this we put tree stage to select materials that able to apply moulding process: Tree=>Process universe=>Shaping=>Moulding press insert. At the end we set a graph price against hardness. It gives us 2 materials.

Despite the fact that the price soda-lime glassis best material, but according to edu pack polymethyl methacrylate is already used in automobile manufacturing.

Question 5:

L2.5.Select materials and process methods to make a light travel case for an electrical equipment (two models – cheap; and up-market, high quality, minimum weight ones).

Using EduLevel 2 material with durability properties, set up fracture toughness minimum 4, thermal property - good indoctor, processability minimum 4 and maximum 5. This is because our suitcase shoud be hard enough to resist high pressure, as speed of light is 3x10^8 m/s and it has to be good conductor of heat so it would not heated up( we assuming).

Additionally, we should add durability :water and aqueous solution – fresh and salted water resistance excellent and good.

By the end we set up 2 graph: first is price and toughness and second density and price:

1. Polyethelyne terephthalate

2. Polyvinylchloride

These products were chosen because they are relatively had cheap price and density and toughness. The reasons are our case should not cost not high and it should be reliable.

Date: 2015-01-29; view: 1355

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