- #1
mecheng2121
- 3
- 0
Hi,
My first post and I'm hoping someone can help/verify a problem I have. I've got a rope with a ball fastened to each end. The balls are secured inside a c-channel. There is a small amount of slack in the rope such that the balls are loose inside the channel (the rope is slightly longer than the distance between the channels).
I then want to apply a distributed load, Fw, across the rope. I can calculate the curavature of the rope and resulting angle, Q, of the rope at the ends from the geometry of the application (I'm going to assume no stretching of the rope or deflection in the channels).
I want to calculate the tension applied to the ball ends. What I come up with, based on my FBD, is the tension, T, on each ball end is equal to the distributed load, Fw / 2 sin(Q).
The problem, which I can't get my mind to accept, is that as angle Q gets very small (if I allow very little slack in the rope), the tension on the ball ends gets very large... much more than the input, distributed load Fw.
Then, if I play a little mind game & take it a step further by replacing the rope with say, a very stiff steel I-beam fastened to a wall at the ends, Q would be infitesimally small resulting in an incredibly large tension T pulling on the wall... how could a building ever be constructed to hold against an extreme tension even with a small distributed load?
Any comments would be greatly appreciated... Am I on the right track? Do I have to simply accept that my ball ends need to be ready to handle a ton of tension? Does my mind game make sense and if so, how can that be? Thanks!
My first post and I'm hoping someone can help/verify a problem I have. I've got a rope with a ball fastened to each end. The balls are secured inside a c-channel. There is a small amount of slack in the rope such that the balls are loose inside the channel (the rope is slightly longer than the distance between the channels).
I then want to apply a distributed load, Fw, across the rope. I can calculate the curavature of the rope and resulting angle, Q, of the rope at the ends from the geometry of the application (I'm going to assume no stretching of the rope or deflection in the channels).
I want to calculate the tension applied to the ball ends. What I come up with, based on my FBD, is the tension, T, on each ball end is equal to the distributed load, Fw / 2 sin(Q).
The problem, which I can't get my mind to accept, is that as angle Q gets very small (if I allow very little slack in the rope), the tension on the ball ends gets very large... much more than the input, distributed load Fw.
Then, if I play a little mind game & take it a step further by replacing the rope with say, a very stiff steel I-beam fastened to a wall at the ends, Q would be infitesimally small resulting in an incredibly large tension T pulling on the wall... how could a building ever be constructed to hold against an extreme tension even with a small distributed load?
Any comments would be greatly appreciated... Am I on the right track? Do I have to simply accept that my ball ends need to be ready to handle a ton of tension? Does my mind game make sense and if so, how can that be? Thanks!