):-{])) <---- madden@netcom.com madden@svpal.org Remember amateur astronomers: "keep looking for the next Universe"
On Fri, 21 Apr 1995 HOFFMAN@wmich.edu wrote:
> IMHO -- Since an index of refraction is specified, that sounds like
> the properties are for the pure resin, which must be transparent.
> However, the PVC compound used for making pipe is full of fillers
> to extend the resin and much modify the mechanical properties.
> Maybe a way to find out is to "run it backwards". Take a 10' length
> of 4" pipe, put a short piece of steel pipe crossways under each end
> on a concrete floor. Rig up a dial indicator on a stand so as to measure
> the height above the floor of the top (or better, the bottom) of the
> center of the PVC pipe. Then apply a "concentrated load" (a bag of
> sand or concrete mix, etc.) of known weight to the middle of the PVC
> pipe, and measure the deflection with the dial indicator. Knowing the
> span of the PVC pipe between the steel pipe supports, the ID and OD of
> the PVC pipe, the weight of the load, and the deflection, the program
> can be run so as to figure out Young's modulus for the PVC. Maybe an
> easy experiment for someone with a dial indicator on an adjustable
> stand. Any volunteers?
> Richard Hoffman
>
>