2 Replies Latest reply on Jul 9, 2012 5:27 PM by Louis Moskven

    Understanding the results of fatigue tests

    Yuval Rom

      1. After running a fatigue analysis you get a life plot on the model. My problem is that I don't understand the connection between the s-n curve which I've defined and the life plot results?    

      2. Is it possible to plot a new s-n curve from the results of the fatigue analysis and compare it to curve you have entered (the known curve of the material)?

       

      Thanks

        • Re: Understanding the results of fatigue tests
          Anthony Botting

          Hi Yuval:
          For (1.), I'm assuming you entered the number of cycles of loading for the model in the Fatigue study. If so, the "life plot" should show the "life consumed" at that stress level. Example: if you loaded with 100,000 cycles at 20,000 psi stress, and the s/n curve lookup shows life at 20,000 psi is 1,000,000 cycles, then the plot should show 10% of life is "consumed" (100,000/1,000,000). Does that make sense? I believe the legend may show "10%" as 0.10.

          For (2.). I'm not sure the request to plot a new s/n curve makes sense, since it's fixed by definition for that particular material (i.e, it would have been entered by the user). Perhaps you mean something else. Can you elaborate a little?

          -Tony B.

          • Re: Understanding the results of fatigue tests
            Louis Moskven

            You may also want to take a look at Miner's Rule (Linear Damage Rule); It's listed in the solidworks simulation documentation as the method used to determine how cumulative damage from a cyclic load affects the life of a part.