Calculate the clamping force to prevent the load from sliding

AI Thread Summary
The discussion focuses on calculating the clamping force required to prevent a rubber clamp from slipping on a vertical steel pipe. The initial calculations suggest a clamping force of 333 N with a friction coefficient of 0.6, which is deemed sufficient to prevent sliding, albeit marginally. However, the importance of incorporating a safety factor, ranging from 2.0 to 10.0 depending on application criticality and environmental factors, is emphasized. Additionally, the effect of the load's moment and the potential impact of wet conditions on the rubber's friction are highlighted as critical considerations. A clear diagram is recommended to better assess the clamping scenario and its dynamics.
KavaKovala
Messages
7
Reaction score
0
TL;DR Summary
Clamping force
Dear,

Could you tell me if the calculations on the attachment are correct? I need to determine the force necessary to prevent the clamp from slipping.

Basically the clamp is a part of rubber that I can press against the pipe wall. A load will be attached to this part of rubber. The tube is vertical.

It's too simple to be true my calculations, lol

Thanks in advanced!

Clamp material: Rubber
Tube material: Steel
 

Attachments

  • tpt.png
    tpt.png
    4.2 KB · Views: 773
Engineering news on Phys.org
If I correctly understand, you have a clamp force of 333 N, a friction coefficient of 0.6, and a force perpendicular to the clamping force of 200 N. You are correct, it will (just barely) not slide. And it really is that simple.

However, any real world clamping problem requires a safety factor. Depending on how critical the application, presence of vibrations, how accurately you know the friction coefficient, and the consequences of sliding, a suitable safety factor could be anywhere from 2.0 to 10.0.
 
  • Like
Likes berkeman and anorlunda
jrmichler said:
If I correctly understand, you have a clamp force of 333 N, a friction coefficient of 0.6, and a force perpendicular to the clamping force of 200 N. You are correct, it will (just barely) not slide. And it really is that simple.

However, any real world clamping problem requires a safety factor. Depending on how critical the application, presence of vibrations, how accurately you know the friction coefficient, and the consequences of sliding, a suitable safety factor could be anywhere from 2.0 to 10.0.

Hi jrmichler,

Thank you for your reply!

Just a doubt, Does the moment created by the load have any effect that must be considered?

I appreciate your help.
 
In order to answer your question, a diagram is needed that clearly shows what is being clamped to what, and how the clamping force is being applied. You need to show actual, rather than simplified, parts. And tell us what happens if it slips.

Keep in mind that, while you understand what you are trying to do, we have only your diagram and text to figure out what you are trying to do.
 
Water is a rubber lubricant. If the rubber gets wet, it may slide.
Check the coefficient of friction for wet rubber.

I assume in your diagram, the pipe is yellow. Is the rubber black ?
Is the blue band around the pipe a clamp, made from rubber or steel ?
What is the lighter blue ?

Hoop tension in a band around a pipe is not equal to surface pressure on the pipe.
Hoop tension is only doubled where both ends meet perpendicular to the clamped block.
 
Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
Thread 'What's the most likely cause for this carbon seal crack?'
We have a molded carbon graphite seal that is used in an inline axial piston, variable displacement hydraulic pump. One of our customers reported that, when using the “A” parts in the past, they only needed to replace them due to normal wear. However, after switching to our parts, the replacement cycle seems to be much shorter due to “broken” or “cracked” failures. This issue was identified after hydraulic fluid leakage was observed. According to their records, the same problem has occurred...
Back
Top