Fracture toughness

[makeup]

Hi all, can anyone help. I am looking for the fracture toughness kic of 50D plate.

Thank you

 

[TVP]

I am not familiar with "50D plate". Can you provide a more complete specification, such as an ASTM standard including chemical composition?

 

[Carburize]

makeup - what thickness of plate and what temperature?
Typically BS 4360 Grade 50D is ductile down to very low temperatures and CTOD is more normally measured rather than Kic

 

[makeup]

Thank for replying,

What I am trying to do is a model of the frature mechanics involved with an Oil Rig disaster we had here in the Uk in the 80's.

One of the leg braces failed by fategue and I am trying to use LEFM to put together a very basic model of the fracture process.

The cracks reportedly propagated out from a hole in the brace, so I thought a good model might be.

1. Find the intensity factor at the crack tip
2. Establish crack growth rate
3. Establish life expectancy etc

From my very limited understanding of LEFM K must reach Kic before the crack will propagate. But what I cant find is a rough estimate of the Kic value for 50d plate.

How would I use CTOD in such a model.

 

[makeup]

I have just found some Charpy results, what do I do will the impact energy to build a fracture model

 

[Carburize]

In my files I found this old, old reference

Offshore Platforms - Proposed Acceptance of Weld Defects
By Barr, Terry and Gulvin
British Steel Corporation Report Prod. 149/4/74/D

My file notes say that it discusses a fracture mechanics based analysis of the sort of structures you are interested in.
I have no recollection of where I got the reference or whether there is any way you could obtain a copy these days but it might be worthwhile doing a search on the authors to see if there is anything else out there.

 

[Carburize]

makeup - The date for the BSC Report was 1974

 

[CoryPad]

Method to convert Charpy impact to fracture toughness:

thread330-24020

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[makeup]

Thanks for your help.

Can anyone recommend a good book on fracture mechanics, something with worked examples would be good

 

[metengr]

Yes;
One of the better books with worked examples is
"Fracture Mechanics, Fundamentals and Applications", by TL Anderson, 2nd Edition, CRC Press

The other book is
"Deformation and Fracture Mechanics of Engineering Materials" by Hertzberg Wiley Press

 

[kclim]

The standards BS 7910 and API 579 will be very relevant and useful. Worked examples are in the standards, but don't expect the same level of explanation that a good college text book would give you.

 

[Carburize]

"Worked Examples in Fracture MEchanics"
By Knott and Elliott
The institution of Metallurgists. Monograph No 4 1979