Fatigue Analysis: Fatigue Specialist vs. Finite Element Engineer
In this blog article I would like to show you a simple fatigue analysis. The analysis is done the way a fatigue specialist will do it and the way a…
Some Thoughts About The Miner Rule
Introduction Fatigue predictions for VA (variable amplitude) spectra are currently based on the Miner-Pålmgren rule using S-N data obtained from CA (constant amplitude) test data. The Miner-Pålmgren rule is a…
The Hatfield Rail Crash: 20 years later
Sometimes we learn about fatigue the hard way. On October 17th 2000 it took 4 dead and over 70 injured persons to learn that maintenance is not just some annoying…
Using the Low Cycle Fatigue approach when Kt * nominal stress exceeds the yield strength: a fundamental mistake!
In my blog article What is the Difference between Low & High Cycle Fatigue? I explained that LCF is characterized by repeated plastic deformation (i.e. in each cycle). Essential here…
What is π doing in the Stress Intensity expression?
Today it is π-day (3/14), a perfect day to wonder what π is doing in the stress intensity factor (SIF) equation. Let us have a look to this SIF equation…
What went wrong with the Boeing 737 NG Pickle Fork?
As you may have read, Boeing has a major fatigue issue with the 737 NG Pickle Fork. Information about the nature of the problems can be found in numerous articles…
“We cover fatigue with static analysis”
Still a lot of people seem to think that sufficient fatigue life can be reached just by doing a static analysis. Hey, my structure can carry a tremendous amount of…
Can structures recover from fatigue?
I like cycling. When the weather is fine (or not so fine) I really like to make a nice tour through the countryside. Sometimes easy going, but sometimes it will…
Fatigue in the Merwede Bridge
During autumn 2016 the Merwede bridge on the A27 in the Netherlands was closed for heavy traffic for 2 months. The reason was the presence of fatigue cracks close to…
Principal Stresses vs. Equivalent Stresses in Fatigue
For those who are not too familiar with fatigue it seems always be attractive to use equivalent stresses like Von Mises for fatigue life analysis. I am sorry, but I…