friction and surroundings

[Guido]

Bye to all,

how do I determine the torque of clamping, diameter and number of bolts in a coupling between metal elements in order to avoid cracking (slitting and cutting of bolts) in the presence of a f force that tends to make "slide" one of the two components, considering a stable ??

I attached a sketch representing the application. the element "a" is stable while the element "b" is bolted to "a" . a force f tends to slide "b".

Thank you all.

 

[PierArg]

Hi.

the torque depends on the bolt material. depending on the type of material you can allow you to tighten more or less. with the torque imprimes to the connection a compression force while on life acts an axial force of traction. this, multiplied by friction present on the surfaces, must be able to win the transversal forces of cutting.

you beat the diameter, the number of screws, the material (as a result the torque and its axial force) and see if they develop the transversal force (obviously taking into account a safety factor) able to resist f. if for example you have four bolts, the f/4 force, if you have 2 will f/2 and so on.

If I find a box, I'll place it.

 

[Exatem]

Look if this can help you.View attachment 17161

 

[numero1]

and thishttp://corsiadistanza.polito.it/corsi/pdf/04asbp/ecm_8_collegamenti_filettati.pdf
ciao

 

[meccanicamg]

look on former cnr 10011 or on eurocode 3. the sizing/verification for friction connections is largely mensed and there are the calculation procedures.

to ensure that a and b are in place you need to provide a known friction force. so that this is possible it is necessary to tighten n screws (which is imposed) with a clamping force less or equal to the maximum one of the type of chosen screw (class of resistance and diameter).