Shear stress and bearing stress, some quesrions?!? 1

[chillwynston]

Hello, I'm a newbie to this site.. I am a design engineer involved with pipework and bellows design, I am designing a unit called a hinged unit, you may have heard you may not. but.. i have a question of stress! i have a pressure end load acting on the unit to restrain this I must use plates and pins (which also let the unit move laterally) I have worked out the shear stress on the pin, but a colleague of mine has informed me I must also design for the bearing stress, can someone give me an explantion of this as looking at the unit I can only see need to work out and design for the shear stress of the pin!? he has given me an equation sq root of end load in lbs divided by 115, I asked about this 115 and was told this is a constant used for bearing stress. can anyone enlighten me more?? Thanks for listening!!!

 

[IFRs]

Bearing stress results from the bolt or pin pushing against the side of the hole. It is from a force perpendicular to the pin or bolt. Besides the force, hole size, material properties and thickness, the edge distance is important - how much metal is there between the edge of the hole and the end of the metal the hole is drilled in. The number 115 sounds like a rule of thumb for some particular condition and not particularly useful in helping you understand. The force divided by the bolt diameter divided by the material thickness would give you an approximate bearing stress. You'd have to look up the allowable bearing stress from a design guide. AISC for steel, AA for aluminum, NDS for wood etc.