Physics: Materials Presentation

[richnfg]

Before saying anything, sorry that my first post on this forum is looking for help. Thats not a good thing, I know. I do intend to post more.

 

Anyway, for my A-level physics coursework I need to give a presentation on a material of my choice...most of the other people in my class got the easier materials / materials with more information on them - I'm stuck with human bones.

 

Ok, any links to information or websites would be really useful.

 

Here are the main topics I am doing about:

 

How strong is the bone?

I need to talk about the breaking stress and include some of the young modulus in there too. I need some data about that and possibly compare to other materials.

 

How does a bone break?

I need to talk about tension and compression and basically how a bone breaks.

 

What happens to the bone as we get older?

I need to talk about how and why the bone gets weaker as we get older.

 

Anything would be useful, especially data and diagrams. It would be a great help and I congratulate you if you read the full post.

 

Thanks...

[blike]

I've got a few notes that may be helpful to you. They're a basic overview of a few things, but it does include a few notes about young's modulus of bones, compression stress, etc.

 

If you'd like, PM me and I'll send you the notes.

[Perennial]

I was once involved in a fracture mechanical case study analysis which concerned about fatigue crack propagation / fracture of fibula (? quite sure, some bone it was at least) ... I think I can get you the material if it sounds interesting ?

[richnfg]

Thanks Blike for the offer, I'll contact you!

 

I was once involved in a fracture mechanical case study analysis which concerned about fatigue crack propagation / fracture of fibula (? quite sure, some bone it was at least) ... I think I can get you the material if it sounds interesting ?

 

Wow, it sounds like it might be beyond my level or more towards a different area of the bone. Has it got anything about the strength of bones etc? (I'm not sure what fatigue crack propagation is )

 

Anything else would still be very useful!

 

Thanks!

[Perennial]

Fatigue crack propagation is essentially what happens when a pre-existing defect (~crack) propagates over a period of time due to fluctuating loading (take as an example a steel axle in a car, they usually have small defects in them, and after repeated loading the defect grows to be large enough to lead to catastophic failure). The case I was referring to has the basic material properties (elastic modulus, yield strength, fracture toughness and other bit more obscure material parameters), some figures about the locally failed area and a pretty detailed (quantitative) analysis on how the failure took place.

[richnfg]

Wow, sounds good!

[Perennial]

If it sounds usable PM me an email address and I'll send it to you.

[Drug addict]

 

What happens to the bone as we get older?

I need to talk about how and why the bone gets weaker as we get older.

 

 

Bone consists of a calcium phosphate crystals attached to a collagenous support matrix. Hydroxyapatite (Ca10(PO4)6(OH)2) is the most common form of calcium phosphate.

 

Bone is a dynamic' date=' living tissue and it is constantly being formed by osteoblasts and broken down (resorbed) by osteoclasts. In osteoporosis, absorption exceeds formation, with reduction in the bone matrix and therefore strength. Bone density decreases from the age of 30, long before people think they are at risk, so prevention is difficult. Treatment can be by correcting any deficiency of calcium or vitamin D. Additional treatments include oestrogens (HRT) and bisphosphonates (eg alendronate [Fosamax']). Bisphosphonates reduce bone turnover, oestrogens reduce the resorption of bone.

 

If you want any information on analysis of bone density let me know.

[richnfg]

Thanks, that is a big help! If anyone could post some figures about Young Modulus and Breaking Stress of bone that would be incredibly helpful.

[richnfg]

I'd just like to say thanks to Blike (for about the 1000th time ) because he was very helpful and so was the information he supplied.

[BAsher2012]

I've got a few notes that may be helpful to you. They're a basic overview of a few things, but it does include a few notes about young's modulus of bones, compression stress, etc.

 

If you'd like, PM me and I'll send you the notes.

 

HEy you don't still have this info by any chance if so email it me ?? ashleyb95@hotmail.co.uk cheers