FRICTION and TENSION, what is the link
FRICTION and TENSION, what is the link
(OP)
Hello gents,
Sorry for my poor English, I will do my best to describe my case I have to resolve.
I have a steel bracket devided by 4 pieces I need to tighten them around a concrete column (diameter 2.5m).
The 4 parts are bolted to one another by 6 bolts.
The height of the bracket is 0.6m
Each 1/4 bracket supports a vertical force 40 Ton.
My problem is I need to know how much torque I need to apply to tighten the bolts to be sure that the bracket is tighten enough to transfer the vertical force by friction to the column. Besides, The vertical forces are offset (1m), which means I have Vertical forces plus a moment.
I will appreciate your help
Many many thanks
Sorry for my poor English, I will do my best to describe my case I have to resolve.
I have a steel bracket devided by 4 pieces I need to tighten them around a concrete column (diameter 2.5m).
The 4 parts are bolted to one another by 6 bolts.
The height of the bracket is 0.6m
Each 1/4 bracket supports a vertical force 40 Ton.
My problem is I need to know how much torque I need to apply to tighten the bolts to be sure that the bracket is tighten enough to transfer the vertical force by friction to the column. Besides, The vertical forces are offset (1m), which means I have Vertical forces plus a moment.
I will appreciate your help
Many many thanks





RE: FRICTION and TENSION, what is the link
Now you know the tension required in the bolts. I have never heard of a direct correlation between torque in a bolt and the tension in a bolt. So I just call out the required tension in the bolts. This leaves it up to the contractor to determine the correct torque. On my project the contractor was a bridge contractor that had access to a rotational capacity calibrator, they used this with a torque wrench to determine the torque to tension correlation.
RE: FRICTION and TENSION, what is the link
I appreciate ur answer and I start having an idea how to deal with my case.
By the way, may be I will ask u a favor is to give me this example with refrences then i can be sur I m not making mistakes. But please feel free to do it or not. no pb.
Many many thanks
RE: FRICTION and TENSION, what is the link
RE: FRICTION and TENSION, what is the link
There are minimum torques though to achieve the required tension for a friction grip bolt. I suggest you use these standard values where possible.
RE: FRICTION and TENSION, what is the link
I am sorry, but I do not have access to my calc file for this project. Hoop stress calculations can be found in just about any mechanics of material text book. Typically under pressure vessel section. Then all you need is the coefficint of friction between concrete and steel.