2 Replies Latest reply on May 29, 2009 2:21 AM by Valery Rutkovskiy

    prop shaft

    Wojtek Mozdyniewicz
      To IAN,

      Shaft is conecting gear box RPM from engine to propeller.
      Bending:
      Overhung Moment (propeller weight): 103.1155 lbf X 4 G X 3.995 inches
      Propeller Gyroscopic Moment: 18 700.7 in-lbf
      Propulsive Thrust: 2758 lbf
      Torque: 18 372 in-lbf

      My task is to define stress graph in the flange with .050 step in machining between shaft and flange.
      . .
        • prop shaft
          Ian Hogg
          Hi Woktek,

          It looks like you have all the loading requirements you need, and each of these is in a form that can be readily applied to the model.

          I assume you are concerned about a stress concentration at the step.
          When you have an inside fillet (concave), it is important to include it in the geometry to ensure any stresses you get in the area of the transtiion in diameter are correct. It is also important to ensure your mesh is refined in the areas of high stress to ensure that there is not too large a stress variation over the elements. The best way to do this is run the model and add refinement until the stresses in that area converge.

          There is an automatic tool (h-adaptive meshing) that you can try under the solve parameters. It can be a little hit or miss on when it works depending on geometry complexity, but it is an efficient way to get accurate results in high stress areas. You can alternatively apply local mesh controls in the areas of high stress to improve accuracy.

          There are examples that demonstrate these approaches in the training material.

          If you have specific issues or questions then you need to specify what they are.

          As I said on the other thread, there's really no need to post things specific to people, just explain what you're trying to do and what the problem is and there are plenty of people who respond.

          Cheers,

          Ian
            • prop shaft
              Valery Rutkovskiy
              Wojtek

              I believe static FEA calculations is only very first step in your case. It will give you only estimations of the shaft design.
              For rotating equipment fatigue is vital. So please read fatigue related books. If you will abble to create load history files you'll be abble to create damage matrix even use so simple tool like Cosmos. Finally you can estimate life of you shaft in rpm.