Without knowing the masses and the moments involved,
The model can return the area of the body, and from that its volume can be approximated, which combined with the densities can allow an reasonably accurate mass to be determined.
It comes out at 0.75 Kg.
However, this is a 2D finite element analysis, so the model is an infinitely thin radial (cross-axial) slice of the mechanism, which leaves me questioning the relevance of the total mass? Or whether there is any useful subdivision of it that can be used?
The model can return a figure labeled as: "R^2 (ie. Moment of Inertia / density )", and further defined as: "Integral of (x^2 + y^2)".
Which for the body in question gives a value of:9.88017e-8 m^5.
But, at this point, I have no idea what if any relevance or use that has in what I am trying to calculate?
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
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You could use linear density (mass per unit length) if you want the mass. You only need the mass if you want accurate calculation of the speed in real units. If you just want the motion around the spindle, you can set the mass=1 arbitrary unit and integrate the magnitude of F_perp as you go around to determine the relative speed at any given point.
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you can set the mass=1 arbitrary unit and integrate the magnitude of F_perp as you go around to determine the relative speed at any given point.
That's an interesting notion, although it's hard to see what the calculated speed would be relative to?
In as much as, whilst I have to enter a "known starting point" to the FEA, it does not necessarily follow that that starting point is stationary. The forces acting are the same regardless of the instantaneous velocities of the components they are acting upon, and they remain the same from beginning to end of the infinitesimally small time delta over which the integration runs.
So even if the result of the integration of F_perp came out as zero, it wouldn't mean that there was either no speed, nor no change in speed, simply that no change had occurred within that tending toward zero delta?
That means that the calculated forces will not have any affect within the time delta of the simulation; and thus will only take affect between simulations; which I think means that the FEA cannot tell me anything about the rate of change that will occur as a result of the forces it calculates?
At which point my brain hurts and I'm gonna sleep on it to see if this all still makes sense to me when I read it back in the morning; or if I've just thunk my way into a blind alley :)
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
In the absence of evidence, opinion is indistinguishable from prejudice.
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