×
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

Seismic Forces on Suspended Equipment

Seismic Forces on Suspended Equipment

Seismic Forces on Suspended Equipment

(OP)
    Thank you for helping me with the previous thread.  Now I have a situation with a conveyor belt system supported overhead from the roof joists of a warehouse.  I know the forces on this will come from the roof, but how do I treat the swinging action on the conveyor.
    I cannot brace it against anything, so the supports must be very stiff.  How much deflection is acceptable?  Also, do I need to analyze the entire warehouse, or can I just find the local forces only?

RE: Seismic Forces on Suspended Equipment

The analysis of the suspended equipment is the same as equipment anchored on the floor of a building.  The only mass of the system that is involved in the dynamic excitation is from the conveyor's own mass and the natural period of the suspended system.  Thus you need only look at the support system for loads to the support.  This assumes, of course, that the conveyor supports aren't part of the building's lateral force resistance.

Never say never.  There are many devices (struts) available to absorb the energy during a seismic event.  Check with Taylor Devices and others for more information.  Also check out the piping industry as many of these suspended pipes use so-called anti-seismic struts to mitigate problems as well.

If your going to be working in this area, you may want to check out a few of the titles available from FEMA/NEHRP on seismic design guidelines, rehabilitation, and non-structural damage mitigation.

Good Luck.

RE: Seismic Forces on Suspended Equipment

(OP)
    Thank you for the help, Qshake.  I looked into the FEMA and NEHRP websites and couldn't find info on publications specific to my needs.  I did get the SEAOC Blue Book and it is very helpful, but what I really need is a specific design example.  I looked into the SMACNA for loads on suspended HVAC and similar, but to no avail.  Do you have further ideas for example problems?  
    My suspended conveyor is attached to an 8 inch tilt up wall at one end and a vertical support at the other.  I feel this helps for displacement, but if the wall anchors are overloaded, I can put some diagonal hangers in to resist the load.  Am I on the right track?
   

RE: Seismic Forces on Suspended Equipment

You're right on track.  I suggest that you check out the UniStrut website and choose literature and then the seismic product information catalog.  This is a PDF document that shows the framing including diagonals and has examples too.

Good Luck.

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