hexagon logo
Register Sign in
  • State Not Answered
  • Replies 27 replies
  • Subscribers 3 subscribers
  • Views 292 views
  • Users 0 members are here
Options
Related

Modeling of Bolts

ron.kunz
Dear all,
I have a big assembly and want to model bolts in the complete assembly. What is the best and accurate way to model this.
Cbar analysis is accurate enough to analyse the bolt forces. Boltstress is of secundair interest.
Are there examples for these bolts?
In addition bar orientation for this CBAR property, how can this best be modeled?
 
Thanks in advance
Parents
  • 0
    The number of Subcases is NOT related to the number of bolts.
    You need a BOLT entry for each "bolt" you want to preload.
    Enter your preload as a FORCE on GRIDC (control node) of each BOLT. Each force can be a different magnitude (like any force input). Your Subcase LOAD= needs to point to all the FORCE cards.
     
    Assuming you want to "lock" the bolt, you need to use a displacement at the control node. With SOL 101, this takes 2 steps:
    1) In the first run, the preload is defined with forces at the control grids.
    2) In the second run, the preload is defined with displacements at the control grids (using displacements from #1 above).
    So, my example (with 4 subcases), isn't something you can do in the real world (because you don't know the displacement for subcases 2 and 4 until you have the results from subcase 1). I put them together to keep things simple.
    In the real world you might use this process:
    Job 1/SC1: preload forces to get control node displacements
    Job 2/SC2: preload displacements (optional - as a check on preload forces)
    Job 3/SC3: pressure only, gives load distribution without preload (optional)
    Job 4/SC4: pressure + preload displacements
     
    Once you're confident in creating preloaded bolts, you only need to run Job1/SC1 and Job4/SC4.
     
     
     
     
     
     
Reply
  • 0
    The number of Subcases is NOT related to the number of bolts.
    You need a BOLT entry for each "bolt" you want to preload.
    Enter your preload as a FORCE on GRIDC (control node) of each BOLT. Each force can be a different magnitude (like any force input). Your Subcase LOAD= needs to point to all the FORCE cards.
     
    Assuming you want to "lock" the bolt, you need to use a displacement at the control node. With SOL 101, this takes 2 steps:
    1) In the first run, the preload is defined with forces at the control grids.
    2) In the second run, the preload is defined with displacements at the control grids (using displacements from #1 above).
    So, my example (with 4 subcases), isn't something you can do in the real world (because you don't know the displacement for subcases 2 and 4 until you have the results from subcase 1). I put them together to keep things simple.
    In the real world you might use this process:
    Job 1/SC1: preload forces to get control node displacements
    Job 2/SC2: preload displacements (optional - as a check on preload forces)
    Job 3/SC3: pressure only, gives load distribution without preload (optional)
    Job 4/SC4: pressure + preload displacements
     
    Once you're confident in creating preloaded bolts, you only need to run Job1/SC1 and Job4/SC4.
     
     
     
     
     
     
Children
No Data
© 2025 Hexagon AB and/or its subsidiaries. Privacy Policy | Cloud Services Agreement