Cantilever Beam Deflection Results Does't Agree with Theory
Cantilever Beam Deflection Results Does't Agree with Theory
(OP)
Hi all
I was doing a cantilever beam static loading analysis. I need to find its deflection with loads added. Then, the result from Abaqus will be used to compare with the result from theory equation. However, my result from abaqus is so weird and has a huge difference with theory result. I cannot figure it out.
My beam has the length 0.6m, width 0.02m and height 0.001m. The material is Steel with E=2.23e11 v=0.3 and density is 7833.33kg/m^3. So, its own weight was simulated as a pressure force on the beam that is 76.845N/m^2. All units used SI meter.
However, Abaqus gave me the tip deflection which is 6.16. According to my Unit system, it will be 6.16 meters which is weird and theory gave me 6.55cm :( Then, I tried to load a 0.4905N force at tip. Abaqus generated a 14.9 meters ... and Theory gave me 9.5cm.
Anyone know the issue? Please help me and Thanks in advance.
I attached my ipt.file here.
https://skydrive.live.com/redir?resid=E5B452EC1A48...
I was doing a cantilever beam static loading analysis. I need to find its deflection with loads added. Then, the result from Abaqus will be used to compare with the result from theory equation. However, my result from abaqus is so weird and has a huge difference with theory result. I cannot figure it out.
My beam has the length 0.6m, width 0.02m and height 0.001m. The material is Steel with E=2.23e11 v=0.3 and density is 7833.33kg/m^3. So, its own weight was simulated as a pressure force on the beam that is 76.845N/m^2. All units used SI meter.
However, Abaqus gave me the tip deflection which is 6.16. According to my Unit system, it will be 6.16 meters which is weird and theory gave me 6.55cm :( Then, I tried to load a 0.4905N force at tip. Abaqus generated a 14.9 meters ... and Theory gave me 9.5cm.
Anyone know the issue? Please help me and Thanks in advance.
I attached my ipt.file here.
https://skydrive.live.com/redir?resid=E5B452EC1A48...





RE: Cantilever Beam Deflection Results Does't Agree with Theory
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Cantilever Beam Deflection Results Does't Agree with Theory
I've modeled what you've described (with the exception that I used a gravity load and not a pressure) and the result from Abaqus matches exactly the hand calculated value (6.65cm).
HTH,
Dan
Han primo incensus
RE: Cantilever Beam Deflection Results Does't Agree with Theory
This is my very initial part of my whole project. This part should help me to get through the Abaqus. Unfortunately, I cannot even find the right answer of this simple case.
Actually, I read many tutorials on this topic and followed the procedures to do my case. However, I still cannot get right answer so far. I think this part work should not have many different places with most of basic tutorials. Only thing I think it is special is that this beam is a very thin so it would cause a large deflection. Therefore, the method would have slightly difference and need to be tweaked. Could you tell me is there any special treatment on the procedure?
Do I need to write the plastic property into the materials section due to large deflection?
Thanks
JosephX
RE: Cantilever Beam Deflection Results Does't Agree with Theory
RE: Cantilever Beam Deflection Results Does't Agree with Theory
Han primo incensus
RE: Cantilever Beam Deflection Results Does't Agree with Theory
Yes the geometric order in mesh section was changed to Quadratic before. It would cause the issue on "attempt to generate many increments" if the NL opened.
And I have done a optimization analysis on the number of nodes. It gave me an optimized number of nodes that can have stable results.
the mode you made is in 3D or 2D?
Joseph
RE: Cantilever Beam Deflection Results Does't Agree with Theory
Han primo incensus
RE: Cantilever Beam Deflection Results Does't Agree with Theory
RE: Cantilever Beam Deflection Results Does't Agree with Theory
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083
RE: Cantilever Beam Deflection Results Does't Agree with Theory
http://www.eng-tips.com/faqs.cfm?fid=376
http://www.eng-tips.com/faqs.cfm?fid=1083