Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

S/N Curves in MMPDS-15 1

Status
Not open for further replies.
feajob

feajob

Aerospace
Aug 19, 2003
161
Hi Guys,
I noticed that on page A-7 of MMPDS-15, it is written that "S/N Curves are for a 50 percent probability of survival. We usually assume conservatively few fatigue penalization factors (such as anodizing + shot-peening, surface finish, ...). But, I would like to know if you apply another reduction factor on the S/N Curves of MMPDS to have a better confidence level? If you reduce these curve then please let me know what is your reduction factor? I appreciate if you can share your experience.
Thank you,
A.
 
Replies continue below

Recommended for you

Sort by date Sort by votes
MMPDS Section 9.6.1.11 Estimation of Lower Tolerance Bounds for Fatigue Data describes a procedure to calculate a 99/95 fatigue curve from the information presented in the Handbook. It will shift your fatigue curve to the left (reducing the life at a given stress) by a multiple of the standard error. Your other influence factors would need to applied on top of that.

Doug
 
Upvote 0 Downvote
Status
Not open for further replies.

Similar threads

W
  • Locked
  • Question
Aging Composition of 15-5 PH
Replies
3
Views
2K
EdStainless
EdStainless
Kipmet
  • Locked
  • Question
N&T 4130 impact properties?
Replies
3
Views
361
weldstan
weldstan
R
  • Locked
  • Question
Test locations in Steel Casting.
Replies
5
Views
4K
EdStainless
EdStainless
metaleng123
  • Question
Weld Repair metallurgical influence in Gr.91 welds 2
Replies
17
Views
1K
metaleng123
metaleng123
feajob
  • Locked
  • Question
S/N curves for unnotched 7050-T7451 plate
Replies
8
Views
354
feajob
feajob

Part and Inventory Search

Sponsor

Back
Top Bottom