## multi-bolted joint pressure distribution

## multi-bolted joint pressure distribution

(OP)

I'm interested in determining analytically (other than by FEM) the mounting pressure due to the clamping loads of a bolt SET (i.e., not a single bolt). Any suggestions? Thank you.

## RE: multi-bolted joint pressure distribution

http://www.sensorprod.com/bjoint.html.## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

bolt split rings in bearings and want to know

how the clearance is effected by the clamping.

We simply take the cross section of the total

number of bolts and ratio it against the cross

section of the interfaces and then use this factor

times the stress. I think you can determine how

much the bolts stretch by the clamping force verses

the length, and assume the material below it will

compress according to the above guideline.

## RE: multi-bolted joint pressure distribution

The calculation is based on simple statics, taking moments about a point and solving equations for force at equilibrium. This is assuming that all the parts operate within the elastic range and that the plates are fairly stiff. For inelastic conditions or ultimate limit state it can get a bit more complicated.

## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

Good luck

Derek

WWW.fea-uk.co.uk

## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

## RE: multi-bolted joint pressure distribution

For bending strength only we may allow some gap happen somewhere where the bolts are subject to tensile action.

Contrarily, where tightness need be imparted by the mechanical devices operating on some softer sealeant material, such rubber or neoprene, there must be some differential of stiffness between what compresses and what is compressed... and whatever causes the tightness through compression in the softer material needs deliver a pressure regular enough on the softer material, that only can be attained but through some minimum stiffness of the flanges for every pattern of the bolts.

Economy in the connection itself and the need to limit secondary stresses in pipes etc further describe how to tackle the design of the joints.

## RE: multi-bolted joint pressure distribution

Consider the flange clamping the gasket to be analogous to a beam on an elastic foundation with individual point loads caused by the bolts. The stiffer the beam (flange) is compared to the elastic foundation (gasket), the less variation in foundation (gasket) loading between bolts. It is not so much the absolute stiffness of either the gasket or the flange that matters as much as the ratio of flange to gasket stiffness.