And damn, "truing" a wheel to make the wheel round, not wobble and have equal forces on the spokes is an art. Even done iteratively with small changes one often end up making some part of the wheel worse when fixing one part.
And damn, "truing" a wheel to make the wheel round, not wobble and have equal forces on the spokes is an art. Even done iteratively with small changes one often end up making some part of the wheel worse when fixing one part.
Also, how did you do the FEA models? Did you wind up meshing all the parts, or did you use higher order beam elements for the spokes and rim bits?
The real trick with wheels from experience as a wheel builder is that all the really interesting behavior is in the non-linear region. And you're butting right up against that when you lace the wheels tightly. Calculating that limit is tricky.
(Briefly, Ultimate load limit is ~ the sum of the tension in the spokes in the loaded zone of the wheel, roughly 4 or so with the rims/spokes I was looking at at the time. The tension limit is just under what will potato chip buckle the rim. So there's a complex interaction between spoke stiffness, rim lateral stiffness, and rim radial stiffness that affects performance at the load limit. Helpfully, fatigue durability is also better with higher tension in the spokes, since the fatigue performance goes to hell when you get stress reversals.)
FWIW, My masters was investigating back calculating material parameters from a dynamic pavement test based on time histories of surface loading and displacement at known locations. I basically figured out that the error measure that we were using was pretty smooth as the stiffness of the subsurface layers varied and that it was possible to home in on a stiffness profile pretty consistently if there was at least a plausible guess of what was under there. It took a long time then though, overnight runs were common, and we didn't have clusters then. (also, uphill both ways, through the snow) I bet I could do it in near realtime now on my ipad, but that's a masters thesis for someone else.
Riders of the POWerwheel lacing pattern go so fast it's usually impossible to discern the lacing pattern from the wreckage they leave behind. To compound the problem most POWerwheel accidents are covered up as "space" attacking us with "meteors".
That wheel is probably still going, out there, somewhere.