beam loading question 9i think0

huangyhg

beam loading question ?(i think)
i'd hate to make my first question such an easy one (especially that i can't find the answer to) but hopefully some of you folks can help me out.
when a load is applied to the end of the crank arm (going clockwise) which place on the whole set up would be ideal to place strain gauges?  my initial thought was to place to the gauge in slot 1 (ie the beam pushes the gear around) but after looking at it i think slot 3 may be a better option?
the reason i don't just go try it: i have to glue the strain gauge and i don't want to chance messing it up when removing it.
check out our whitepaper library.
i'm straining to come up with the answer here...
mike mccann
mmc engineering
i would think 1 just because 3 is closer to the arm and it stiffen your x section.
but really, if you are testing it anyway why not just fix the gear and apply load until it fails.  see where the weak point is and put it there.
never, but never question engineer's judgement
hi tonski
best place is position 3, based on the assumption you load vertically through the crank passing between points 3 and 4 and that your crank is restrained from rotating, although if it could turn its pivot point would be the sprocket centre. i haved based this on the theory of:-
strength of bolts withstanding torsion generated shear loading
hi tonski
further to my original post you may wish to place a gauge at position 1 also, as i agree with the point coengineer made about the change in section.
desertfox