×
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

ASME NG-3232 Primary and Secondary Bolt Stresses

ASME NG-3232 Primary and Secondary Bolt Stresses

ASME NG-3232 Primary and Secondary Bolt Stresses

(OP)
The company I work for uses NG-3232.1, to qualify fasteners.  I have a question concerning primary and secondary bolt stresses.  I am having a hard time grasping the understanding of a primary and secondary stress and wanted to make sure that my understanding of the topic so far is correct.

Pm is the primary membrane stress, which is only the preload applied to the bolt via torque.  Only thermal expansion would lessen the preload, hence the tight join check for 3232.1e against external loads.

So for Pm primary stress, there will always only be the preload and thermal expansion forces??

Then the Pb would be any primary bending stresses due to the initial preload?

Then my second part of the question is for Qm and Qb the secondary stresses.  A secondary stress will only be evaluated if it is a limiting stress correct?  In other words, if an external force is not limiting, it is not considered to be a secondary stress when evaluating the fastener.  Also, I was wondering if anyone could provide a few examples of a limiting stress.

Thank you for your help everyone.
 

RE: ASME NG-3232 Primary and Secondary Bolt Stresses

(OP)
Also, does anyone have a good reference for more information of fasteners and understanding stresses?  Thanks!

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