Two of the most important reasons to have a meeting are 1) review the progress the attendees made since the last meeting and then plan the next steps, especially those that are connected or 2) to communicate something everyone needs to hear at the time (with Q&A.)
Insist on an agenda for every...
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...
The strength of the machined part is a function of the original thickness of the plate. So if you machine a part from a 4 inch thick plate of 7075-T73 so that the walls are 1 inch thick or less, the strength of that wall is still that of the 4 inch thick plate you started with (accounting for...
The world ain't all sunshine and rainbows. It's a very mean and nasty place, and I don't care how tough your are, it will beat you to your knees and keep you there permanently if you let it. You, me or nobody is gonna hit as hard as life. But it ain't about how hard you hit, it's about how hard...
We might be in violent agreement on certain aspects of this debate. An expert is someone who knows a great deal about a wide variety of problems encounter in a discipline, and I've never seen anyone reach the level of expert in anything in less than 10 years of devoted practice. It takes that...
ROTW:
I agree that everyone who will succeed professionally must work in the right environment (right is different for everyone) and that must include mentors, but having the right environment and mentor will NEVER make you an expert; only you can make yourself an expert (and not everyone...
According to one estimate, it takes 5000 hours of dedicated effort to become an expert at one thing. That's 2 hours per day, 5 days per week, 50 weeks per year for 10 years. Then you have to use it or lose it. Self-study is the only way to become an expert. No degree will do it. Even a PhD is...
Pencil and paper remain the most useful tools on an engineer's desk. If you can't estimate the answer with those tools, you shouldn't trust the answer you get with an electronic device. As a stress analyst mentoring apprentices, I insist that they use Roark & Young and Peterson to estimate upper...
All you points are perfectly valid for the scenario I introduced of a failure do to a rare defect. But, if that 1 in a 100 failure is due to variation in loads, then running all tests to failure will give you much more insight than if all the tests survive. All surviving tests provides no...
It depends on your reliability requirement and the quality of the component/material being tested. If you have a rare defect that leads to failure one time in 1000, you cannot run 10 tests that all survive the test and then declare you have demonstrated that the life will be equal to the...
Vince Adams book is very good for the practical engineer but offers much less on the theory. If you want to know how shape functions work, its not the book for you. If you want to know what potholes to watch out for, it's a great book. Vince is an experienced practitioner and the book reflects...
Actually, rb1957, in a fatigue test, a runout provides much less information than a fail, not slightly less. Statistical analysis of SN data is very complicated. Handling runouts is the hardest part. The random fatigue limit model (Pasual & Meeker, Technometrics, 1999) accounts for runouts using...
I highly recommend that you review chapter 9 of MMPDS and try to find a copy of Analysis and Representation of Fatigue data by Conway and Sjodahl. Those two sources are by far the most complete, in my opinion.
The standard equation in MMPDS is log(N) = A + B*Log(Seq - C) models only the...
