Coefficient of friction in regards to a clamp force

[Nik_Barbour]

Does coefficient of friction change in regard to clamp force applied to parts?

If you imagine a bench vice, clamping a plate with a weight attached.
Can the clamp force required be calculated to hold a specific weight?

I'm asking because I have an excavator mounted hammer EMV outside. It holds a piling sheet which weighs 800kg between the end of a hyd cylinder and an opposed static clamp face both of which are steel, and I wanted to calc the min force of the ram required to clamp and allow us to pick up the 800kg safely.

Any help or advice would be much appreciated.

Thanks in advance.

Nick

 

[haruspex]

Does coefficient of friction change in regard to clamp force applied to parts?

If you imagine a bench vice, clamping a plate with a weight attached.
Can the clamp force required be calculated to hold a specific weight?

I'm asking because I have an excavator mounted hammer EMV outside. It holds a piling sheet which weighs 800kg between the end of a hyd cylinder and an opposed static clamp face both of which are steel, and I wanted to calc the min force of the ram required to clamp and allow us to pick up the 800kg safely.

Any help or advice would be much appreciated.

Thanks in advance.

Nick

You need to have some idea of the coefficient of friction between the clamp and the sheet. Based on the materials you should be able to look that up online, but it will also depend on the cleanliness of the surfaces.

 

[CWatters]

I would suggest you need a good safety margin in the calculation.

 

[sandy stone]

Aren't there specially made clamps for sheet goods where a downward movement of the sheet results in an increase in clamping pressure?