Almost Embarrassing - Moment for Constant Curvature?
Almost Embarrassing - Moment for Constant Curvature?
(OP)
How do you determine the moment for a shape that will be bent to a constant curvature. This would give it a constant moment along the length.
As an example. I have a solid steel bar, and want to bend it in the field to a radius of 60 feet. (It shouldn't matter, but there will be a series of supports holding the bar to the radius). The bar has a moment of inertia of 0.3 in4, and is made of steel.
It's easy enough to plug the problem into RISA or the like, but how do you solve this by hand?
Thanks.
As an example. I have a solid steel bar, and want to bend it in the field to a radius of 60 feet. (It shouldn't matter, but there will be a series of supports holding the bar to the radius). The bar has a moment of inertia of 0.3 in4, and is made of steel.
It's easy enough to plug the problem into RISA or the like, but how do you solve this by hand?
Thanks.






RE: Almost Embarrassing - Moment for Constant Curvature?
RE: Almost Embarrassing - Moment for Constant Curvature?
RE: Almost Embarrassing - Moment for Constant Curvature?
In addition to the above I would assume that the method of bending the bar would produce residual stresses.
I think we need more information from you.
Also:
Wouldn't a shape of constant curvature be a circle or some part of it?
RE: Almost Embarrassing - Moment for Constant Curvature?
Are you trying to hold this bar elastically to that radius, in which case you're building in this moment, or plastically deform the bar to that radius? You may have to apply a larger moment to yield the bar in order to deform it.
RE: Almost Embarrassing - Moment for Constant Curvature?
This bar will be fabricated straight, and field bent into this curvature creating residual elastic stresses in the bar. It will then withstand additional stresses created by loading.
Thanks for the advice everyone.
RE: Almost Embarrassing - Moment for Constant Curvature?
how do you plan on bending it ? (i'd start in the middle, and work towards both ends at the same time)