×
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

Command to control member shrinkage

Command to control member shrinkage

Command to control member shrinkage

(OP)
If you have axially loaded members (i.e. externally applied load in kips)....is there a command to tell STAAD not to consider their shrinkage/elastic compression from a axially applied load?

Why we are on the subject, isn't there such a command for shear displacement as well? Thanks.

RE: Command to control member shrinkage

What you describe isn't what I would call shrinkage, it's deflection due to the applied load.

There are ways to control what type of deflection occurs in a member. Say you have a beam that you want to be infinitely stiff in the axial direction. The axial stiffness of a member is AE/L. So, you can modify A, E or L to manipulate the stiffness.

To eliminate both shear and axial deflection, you could merely manipulate the member so that it has an extremely large Area (A). Though, if you do this you will want to make sure the density of the material is set to zero or else you will probably get an unrealistically large weight because of the increased area of the member.

RE: Command to control member shrinkage

(OP)
Found the command for shear: Set Shear

If anyone finds the command for axial compression/tension....let me know. Will continue to look.

RE: Command to control member shrinkage

I don't think you can override axial deformation. You could make the section extra stiff (large E) and then assign a cracked factor reduction for bending (RIX, RIY, RIZ) I suppose.

RE: Command to control member shrinkage

(OP)
thanks seth.

RE: Command to control member shrinkage

I'd be more inclined to take Josh's approach and increase the cross section area and reduce the self weight to increase the axial stiffness. While Seth's idea of increasing the E would work also it would have additional impacts on the flexural stiffness of the members which I think you'd want to avoid if possible, which is what Seth's suggestion on adding crack factors would help get around. For me personally I'd find it simpler to do the area/self-weight modification.


Open Source Structural Applications: https://github.com/buddyd16/Structural-Engineering

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

White Paper – Your Construction ERP RFP Checklist
Selecting business software for a medium to enterprise-sized construction concern is extremely challenging in large part because most enterprise resource planning (ERP) suites originated in the world of repetitive manufacturing and are therefore a poor fit for a project and asset-centric business. However, midsize to large contractors need the predictable, auditable processes that ERP delivers. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close