Tensile strain / safety factors

[giraffasaurusrex]

Homework Statement

Hi all.. I would really appreciate any help anyone can give me! I have tried to solve the following and although I understand a) (I think!), I am really unsure between the two possible formulas to use for b), and my answer for c) just seems wrong..! If I am making an obvious mistake I'd love to know..

Thanks in advance!


A load of 50 kN is applied to the tensile member shown in fig. 3. The axis of the rivet is at 30° to the line of action of the load F.

a) calculate the tensile and shear stresses in a 20mm diameter rivet.
b) calculate the tensile strain in a 20mm diameter rivet.
c) if the ultimate tensile stress of the rivet material is 350MPa and it's modulus of elasticity is 150GPa, find the safety factor for the above rivet in operation.

Relevant Equations

Stress=force/area
Strain=Lx/Lo
Elasticity=stress/strain
(Area=πd sq/4)

 

[Chestermiller]

Your normal and tangential components of force look OK. What is the shear stress and tensile stress in the bolt?

 

[giraffasaurusrex]

Oh no! Thank you, yes I see the mistake now - I want to say I was focusing on B and C but that would be shameless self promotion (:
This would be the F/A I forgot wouldn't it..? Thank you so much!