Plastic Pipe Crushing
Plastic Pipe Crushing
(OP)
Hi,
Bit of an oddball one. I would like some advice if possible.
Client has a sheave block which supports rope over a 90 degree bend. (see below)
They're taking the sheave out for servicing and don't want it to bend over a sharp radius (fair enough) and have asked for a length of plastic pipe to be used to support the ropes.
i have checked and the pipe is adequate in terms of min. radius for the rope.
although not heavily loaded (self weight of pipe only - tension is removed), how would one check the pipe for crushing?
i do have mechanical specifications of the pipe, i.e. tensile modulus, poisson's, and yeild stress.
i can work out the resolute force being applied, but have never come accross checking a pipe for local damage like this (traditionally treated them as a member or subject to hoop stress).
Regards, Joe
Bit of an oddball one. I would like some advice if possible.
Client has a sheave block which supports rope over a 90 degree bend. (see below)
They're taking the sheave out for servicing and don't want it to bend over a sharp radius (fair enough) and have asked for a length of plastic pipe to be used to support the ropes.
i have checked and the pipe is adequate in terms of min. radius for the rope.
although not heavily loaded (self weight of pipe only - tension is removed), how would one check the pipe for crushing?
i do have mechanical specifications of the pipe, i.e. tensile modulus, poisson's, and yeild stress.
i can work out the resolute force being applied, but have never come accross checking a pipe for local damage like this (traditionally treated them as a member or subject to hoop stress).
Regards, Joe






RE: Plastic Pipe Crushing
"plastic" is very vague. Just make it solid and your problem goes away.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Plastic Pipe Crushing
RE: Plastic Pipe Crushing
I’d take a 3' long piece of 6-8" dia. oak log or a landscape/cribbing timber for that matter, and rip it down the approx. middle, to produce a flat side. Bolt this to the deck (or whatever) with some overhang on the outer edge. If it is a rectangular timber, rip one corner to 45̊, and round the remainder of the corner. Put a couple half round 2x10 end plates on it to retain the rope, and call er a day.
RE: Plastic Pipe Crushing
BSVBD - see above re: material. for steel i would have a similar problem: i haven't come accross the load case on a pipe.
Dhengr - although i agree timber is suitalbe outside scope.
Further info Pipe is approx 500 mm OD, agricultural type
RE: Plastic Pipe Crushing
RE: Plastic Pipe Crushing
RE: Plastic Pipe Crushing
Beware of the creep properties with PE at least. what starts as a round pipe, might be an oval one after a couple of days...
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Plastic Pipe Crushing
RE: Plastic Pipe Crushing