Discussion Groups

Simulation Mechanical and Multiphysics

Distinguished Contributor
Posts: 108
Registered: ‎03-16-2012

beam k factor buckiling

288 Views, 5 Replies
04-10-2012 12:05 PM

Hi

Can some one throw some light on the effective length factor k  of a beam﻿﻿﻿﻿ (say rectangular c/s strong axis is 2 and weak axis is 3).In this case the beam is a tapered section ie  the c/s areas of the two elements are different.say left most node is fixed and load applied in -Z on theright most node. forgive my cave drawing as I am still using ms paint...

ASIMM 2012
Employee
Posts: 492
Registered: ‎03-25-2010

Re: beam k factor buckiling

Hi magd1,

Sorry, but I do not understand your question. Can you elaborate? For example,

Is the "k factor" related to something in buckling, such as the slenderness ratio or compensation for the constraints?

Or are you referring to the "k-node" which is used to define the orientation of beam elements?

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)
Distinguished Contributor
Posts: 108
Registered: ‎03-16-2012

Re: beam k factor buckiling

04-10-2012 01:01 PM in reply to: INACTIVE_AstroJohn

Hello john

K factor as in buckling. and load is axial (axis 1) not in -Z direction as I mentioned earlier .Find the following.

ASIMM 2012
Distinguished Contributor
Posts: 108
Registered: ‎03-16-2012

Re: beam k factor buckiling

you guys mentioned something here...not clear for my head......

beam checking

I guess this image help a bit.

Let most is fixed and you apply axial load on the right.

Each section is idealised as a beam and supplied the sectional properties.

as you see in the image, there are 6 elements.and the beam is a tapered section.so each section c/s is varying.

So I am concerned about the K factor and how the software approached this issue.

ASIMM 2012
Distinguished Contributor
Posts: 108
Registered: ‎03-16-2012

Re: beam k factor buckiling

hello john

did you get a chance to look into this issue.Any help is appreciated.

thanks

ASIMM 2012
Employee
Posts: 492
Registered: ‎03-25-2010

Re: beam k factor buckiling

Hi,

My first question is what are you trying to calculate?

1. If you want to know at which load your column will buckle, then perhaps you should run the simulation type "Linear > Critical Buckling Load". But it looks like your column is very compact, so read the limitations of the Critical Buckling Load solution.
2. If you want to check the design against the Allowable Stress Design (ASD) code, then you will need to check the written code to see if they have formulas for your arrangement. Off the top of my head, I do not know if they support tapered beams or tubing with a gusset in the middle (is that what I'm seeing in your image, a gusset/rib?) I do not know if this design code is online or whether you need to purchase the Specification for Structural Steel Buildings from the American Institute of Steel Construction (AISC) book.

Sincerely,
John Holtz, P.E.
Senior User Experience Designer, Simulation
Autodesk, Inc.

Current version of Mechanical & Multiphysics: 2013 SP1 (2013.01.00.0012 28-Jun-2012)