What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
(OP)
Dear all,
For metals in Aricraft & Aerospace, if we have fond some small flaws and we need to assess if the flaw will develop to crack that is not acceptable.
What is the applicable Code/std to conduct fracture/fatigue assessment?
Thanks.
For metals in Aricraft & Aerospace, if we have fond some small flaws and we need to assess if the flaw will develop to crack that is not acceptable.
What is the applicable Code/std to conduct fracture/fatigue assessment?
Thanks.





RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
Let me step back a bit...
If your member status shows you in the "Marine/Ocean" industry, then may I guess that you are looking for guidance in the aviation industry because you are not finding suitable answers from design guidelines in your own industry? Which is odd because the monocoque structure of steel ocean vessels has a lot of similarities to aircraft monocoque fuselages, with the exception of scale and environment, and that design requirements existed for them, just like there are for aircraft.
So, where is this crack? In what kind of vessel? Why have you not posted in a forum appropriate to ocean vessels where codes specific to your problem can be addressed?
STF
RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
are you an OEM or a supplier ? if OEM, there should be people closer to you than the internet who can help; if a supplier, talk first to the OEM.
what sort of component are we talking about ? rather than structure, as Sparweb is talking about, I think this is a heavy fitting, with flaws found by ultrasonics ?
what size flaws are you talking about ? another bigger than 0.005" is unlikely to be acceptable.
another day in paradise, or is paradise one day closer ?
RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
For Ocen industry, I know BS 7910 was widely applied to assess Fatigue and Fracture. And I already had experience on this assessment.
For Nuclear industry, I know R6 is utilised.
That is why I am wondering what code to comply with for Aircraft & Aerospace industry. Now I went through FAR 25.571. Thanks to both your reply that I got a clear understanding that the case in Aircraft & Aerospace is quite different from that in Ocean industry.
Thanks.
RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
I see now that you have a deeper background in the subject than I could assume from your first post. Don't be afraid to ask more specific questions - the subject interests us as much as it interests you.
More broadly, sudying the solution to similar problems in different industries can be a trip through history as much as an exploration of the applied sciences. I hope your investigations prove fruitful.
STF
RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
So you see it seems we have very different approaches. There are several online resources that can guide you through the general steps of damage tolerance.
Is this for general knowledge or a future job ?
another day in paradise, or is paradise one day closer ?
RE: What is the applicable Code/std for fracture assessment for Metals in Aricraft & Aerospace engg?
It's good that you read FAR part 25.571 and the related AC 25.571-1D, but much of this material is oriented towards certifying new designs. Since you seem more interested in evaluating damage in existing structures, then I'd also recommend reading AC 25.1529-1A and AC 120-93.
I read a summary of BS7910 which seems to be oriented towards fusion welded structures such as pipelines, platforms, pressure vessels, etc. There is not much fusion welding used to produce modern metal aircraft structures, so this is one area where BS7910 will likely differ from FAA FARs. However, the area where BS7910 and FAA FARs seem to differ most is the approach to ensuring a sound structure during operating life. BS7910 includes a Fit For Service approach that evaluates things on a case-by-case basis. With safety and reliability of metal aircraft structures, the approach used by FAA FARs is strict adherence to controlled/validated/approved processes for everything from design/analysis, throughout manufacturing, and until the component is removed from service.