QAR: Click Here
Conditions for approval required by: Julien Gauther
Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
Form restricted to registered, logged in users. Please return to the home page and use the Create Account option.
In “additional documents” section, another tests at 80% load were carried out.
Load at break is 16263 N (broken bolt) for this additional test.
However, in QTR, for the same test, load at bolt break is 21542 N.
How could we explain such a difference for the same test?
Many thanks in advance,
Best regards.
Understand the surprise at the two “Bolt Break load” values (21542 N in QTR and 16263 N mentioned in the additional test).
I have also seen that in my explanation in the chapter “Particular remarks” of this report not has been clear enough about this test and this has been adjusted.
The first test as shown on the document “Additional test, Axial load test 80%, 5.6 ISO5858” in the “Additional documents” showing that the nut achieves the Axial load required (table 3 of ISO5858) of 13500 N without any problems, also shown in the QTR, page 25 of 43.
At my request, after some time test 2 was performed in the same test setup and with the same bolt and nut (used for the first test). This was to see what the difference is after the bolt / nut has been exposed to the required load (test 1) and a new, so untested bolt / nut. So the difference is the value in the QTR of 21542 N (new bolt / nut) and 16236 N (bolt / nut used for the test 1).
This shows that despite the previous load, the nut continues to meet the required load at a second load test and in this case the bolt is the weak link.
This is the explanation between the two mentioned values (21542 N and 16263 N), where there is no requirement for both values.
Regards
Thank you for this explanation, I read “particular remark” section too quickly, sorry for that.
Approved on my side.
Best regards.