Engineering Questions that need Answering (1 Viewer)

[Mat_Aussie]

What tests for materials are there?

i know of Izod, Charpy

but i dont know what they are tests for? hardness, tensile??

if some one could provide a list of tests and their applications.

The idea of this thread is for the person to answer the question to post another question and the next person does then same and so on and so forth

its a good method of studying and finding out those difficult questions that no1 seems to know.

 

[richz]

yes, i can help u there, but dont keep ur hopes high for this thread to keep on going, not many people visit this section of the forum. ANyway back to the Q:

Hardness:
Rockwel test where u press a pice of metal into the specimen and u measure the penetration
Brinell where u press a steel ball into the surface of the specimen using a kown load and u measure the surface area

Tensile:
to do with elongation, just use some clamps and pull the speicmen with a known force and measure the elongation

 

[Mat_Aussie]

with the hardness tests, do you press it or drop the metal or ball from a height?

 

[richz]

press (10 char)

 

[SDuke]

I think u use a 'tensometer' for tensile testing.

 

[fakingtheday]

AH the infamous testing. There are a shitload. Here they are:

Toughness (impact):
Izod and Charpy: use a notched specimen and are placed vertical and horizontal respectively. The loss in potential energy is the ability to absorb impact. Blah blah blah

Hardness:
Brinell, Vickars and Rockwell all use a tungsten carbide balbaring, diamond pyramid and both respectively. Indentation is an indication of hardness.

Tensile:
Tensometer see stress strain diagram.

Erichson Cupping Test: Measures cupping, duh

Transverse Beam Test: Bending Stress.

I'm sure there are others, i can't remember the name of the fatigue tests but i know iit basically simulates cyclic loadings at an accelerated rate.

Good luck for the HSC boys

 

[Mat_Aussie]

Cheers fellas for your input

my engineering test was a few days ago and now i know that i got at least one wrong

damn testing materials

thanks again

 

[fakingtheday]

I'll only get docked for silly mistakes and things that i don't know/was too lazy to put in. Our teacher is a champ but he rarely gives marks over 95. Anything else? this is good revision for me.

 

[SDuke]

This is in the 2003 HSC.

"Idenitfy ONE advantage and ONE disadvantage of the use of composite materials to replace aluminium alloys in aircraft components"

I'm guessing one advantage is the reduced weight...

help?

 

[SDuke]

Also can u guys help me out with composite materials, if u have any good links pls post them or other references.

My skool notes arnt very helpful as i stumped with all questions concerning composite materials.

cheers

 

[fakingtheday]

The greatest advantage is increased strength to weight ratio. The disadvantage is that composites are suseptible to fatigue stress.

 

[SDuke]

Are composite materials like carbon fibre and kelvar?

 

[fakingtheday]

Yeah, they are a binding matrix with woven fibres to increase dimensional stability.

 

[SDuke]

For some reason i thought composite materials included different alloys of metals - i think i got it confused with non-ferrous metals.

Many thanks