×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Calculate pin in double shear with repetitive impact or vibrational loading.

Calculate pin in double shear with repetitive impact or vibrational loading.

Calculate pin in double shear with repetitive impact or vibrational loading.

(OP)
I'm looking through my Shigley's Machine Design text and I don't see anything specifically for a pin in double shear that has to endure repetitive loading/impact loading. Not sure exactly what it would be called.

The pin is not tight, think of it like a quick release pin from the image below. There is some small clearance between the OD of the pin and the ID of the holes. So I don't think I can calculate it as a simple alternating sheer stress fatigue life. As when the load is being applied then reversed, the pin slams into the other side of the hole.



Is there a way to estimate the life of the pin in this situation? Or is there a spot in Shigley's I should be referring to. I've looked through Chapter 6 (Fatigue Failure Resulting from Variable Loading) but I don't see anything that covers impact.

RE: Calculate pin in double shear with repetitive impact or vibrational loading.

Look in Section 2
B.E.

You are judged not by what you know, but by what you can do.

RE: Calculate pin in double shear with repetitive impact or vibrational loading.

A cyclic reversing load condition in a clevis/pin joint having radial clearance like you describe can get ugly in a hurry. It only takes a small amount of radial clearance to produce large dynamic impact forces at the pin/clevis bore contacts. This loading condition will quickly produce fretting damage to both the pin body and clevis bore surfaces. As the fretting damage to the contact surfaces accumulates, the radial clearance increases, and the failure process becomes self-perpetuating.

I don't think there is any reliable method to predict fatigue life with the joint arrangement and loading conditions you describe, since the failure mode will likely be due to fretting. The best approach would be to re-design your joint to have a proper shear fit.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources