DAMAGE & LIFE VALUES IN FATIGUE ANALYSIS

Sivaprakash_V

Hi Good Evening,

I am trying to perform a Fatigue Analysis for Shaft and Gear Assembly. But I got the Results of Damage as 0 and Life as 1.000E+20.
I didn't the got the expected Results. What are the Other consideration can take into account for performing Fatigue.

Adriano_Koga

hi,

unfortunately, fatigue assessment is a huge field, and there are so many effects that might come into play and affect your results that it is impossible to point all.

 

First:

- loading is ok? what kind of loading you have?

- what are you comparing to? test data? real world issues? analytic solution?

- material curve for fatigue and parameters are ok? is that SN? where does the material data come from?

- does your model represent well the stress distribution (disregarding fatigue, for now). fatigue damage is really affected by your FE model quality, and a small error in stress might cause a huge difference in damage/life

- what tool exactly you're using for calculating the fatigue? OptiStruct? HyperLife?

- are you familiarized with the tool? have you run a simple known model that you can compare to analytical solutions? if yes, at least the workflow you're using should be fine

 

In summary, there are a bunch of places to check, to make sure you will have a better representation.