14 Replies Latest reply on Nov 14, 2018 10:13 AM by Matt Langford

    Linear Dynamic study with harmonic loads: Why no centrifugal loading?

    Matt Langford

      I'm modeling a rotating propeller that is exposed to harmonic loading (from the torque impulses of an internal combustion engine). I'm able to model the torque impulses correctly, but I notice that "Centrifugal" is no longer listed as an "External Load" option, like it is in a Linear Static or Frequency analysis. Centrifugal loading has a first-order effect on the calculated stresses and dynamic characteristics, so I need to capture this body force if I want an accurate analysis.

       

      -Is this an oversight on the part of the Simulation developers, or is there some fundamental reason why centrifugal loading was omitted from Linear Dynamic studies?

      -Is there a workaround? I tried to simplify the centrifugal load as an equivalent radial force acting on the blade tips, but this obviously produced very different results than what I saw in the static study that incorporated true centrifugal loading. It could also be modeled as a nonuniform force distribution acting on the blade surfaces (F=mrω^2), but that would require calculating the radial mass distribution, and I couldn't figure out how to do that easily.

       

      Any ideas?