Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
(OP)
Hi All,
quick question, I have a situation where i have a cantilever beam and i have been told that on the free end there is a bending moment load only of 1000 Nm and the overall length of the beam is 2 m.
What would the vertical load be on the fixed end??
Best Regards
Jonnox
quick question, I have a situation where i have a cantilever beam and i have been told that on the free end there is a bending moment load only of 1000 Nm and the overall length of the beam is 2 m.
What would the vertical load be on the fixed end??
Best Regards
Jonnox






RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
Dave
Thaidavid
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
Thaidavid
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
Thank you for your response. I will go into detail a little bit more so you understand my true problem.
I have a beam that has both a vertical force on the free end and a bending moment (or so I am being told) and I was wondering the best way to assess the problem. Hopefully find attached a picture i quickly drew of the set up i have been presented. I'm wanting to find out what are the loads in the 2 fixing studs/nuts?? I'm not needed to be to accurate as i am also getting some FEA done but I was interested in the best way to tackle this problem by hand calculations.
Best Regards
Jonnox
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
Dave
Thaidavid
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
So let me know if I'm getting this correct............
The first bolt will have a load going through in the vertical direction equal to that of Fz. So 500N only?? Does the bending moment not apply anymore force through this bolt?
The second bolt will have a load from the Bm and Fz with the first bolt acting as pivot point?? So as said 500N(2M) + 1,000N-M = 2,000N-M/0.1m = 20,000N.
I'm also looking at what roughly the force will be going into the ground through the bolts.
If the combined bending moment at the first of bolts is 2,000N-M this must put some additional loading on than first bolt other than just the 500N??
Sorry if I'm not getting it completely!
Best Regards
Jonnox
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
- Sum the moments around CL1. This allows you to solve for a tension force in the back bolt: 500N*2m + 1000Nm + 0.1m*R2 = 0 ==> R2 = -20,000N
- Sum the vertical forces. This allows you to solve for the compression force in the front bolt: -500N - 20,000N + R1 = 0 ==> R1 = 20,500N
If you put this in any FEA program with the bolts modeled as pinned supports it should verify this (and it wouldn't take more than a few minutes to model it as you have it shown).
RE: Vertical force at the fixed end if bending moment is applied to the free end on a cantilever beam
If we ignore the moment restraint provided by the bolt heads (which is a reasonable simplification), then we have a straight beam with two simple supports. The solution is as given in previous posts, but can be generalised as:
Take moments about one support to find the reaction in the other support (from moment equilibrium)
Resolve forces to find the reaction in the support you took moments about (from force equilibrium)
Note that the force in the first bolt is very much greater than the applied 500 N load.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/