Engineering Tensile strain / safety factors

Thread starter giraffasaurusrex
Start date Sep 29, 2021
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Factors Safety Strain Tensile

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The discussion centers on calculating shear stress and tensile stress in a bolt, with participants confirming the normal and tangential components of force are acceptable. A participant realizes they overlooked the importance of force over area (F/A) in their calculations. The conversation highlights the need for accurate stress analysis in engineering applications. Clarifications are made regarding the focus on specific components of the force. Overall, the importance of understanding stress factors in bolts is emphasized.

Sep 29, 2021

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)

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Sep 29, 2021

Chestermiller

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

Sep 29, 2021

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!

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