Deflection and moment diagrams using AutoCAD
Deflection and moment diagrams using AutoCAD
(OP)
Dear all
Am I able to calculate the final deflection of a beam from the bending-moment diagram graphically using AutoCAD, please?
Am I able to calculate the final deflection of a beam from the bending-moment diagram graphically using AutoCAD, please?






RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Deflection and moment diagrams using AutoCAD
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Deflection and moment diagrams using AutoCAD
Can you provide some details?
To answer your second question, no, i wouldn't want to. But I`m curious about the procedure just to learn more about CAD.
I recently learned it can calculate properties of a cross section (Ixx, Iyy, rx, ry, Sx, Sy, y-bar, etc) and that's saved me a huge amount of time
RE: Deflection and moment diagrams using AutoCAD
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Deflection and moment diagrams using AutoCAD
But that said, you could generate a slope diagram by finding the area under your moment diagram, then generate a deflection diagram by finding the area under your slope diagram, then rotate the deflection diagram so the deflection at the supports was zero.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Deflection and moment diagrams using AutoCAD
The conjugate beam is an imaginary beam loaded with the M/EI values of the real beam. The shear at any point in the conjugate beam is equal to the slope of the real beam at the same point. The bending moment at any point in the conjugate beam is equal to the deflection at the same point in the real beam.
If you are not familiar with the conjugate beam method, Google "conjugate beam method". It really is a very useful way to find deflections, particularly for simple span beams.
BA
RE: Deflection and moment diagrams using AutoCAD
In 2010 I think Autocad introduced the parametric design feature that allows to make curious things within the program. I made about 50 dwgs to explore the tool, mainly some math (finding roots, euclidean geometry, and graphic statics, such push on walls, funicular determination of moments etc). Unfortunately I don't find as of now where I have the examples if I have managed to preserve them, so I can't post any as of now. But through funicular determination of the moments certainly it can be done as BAretired says by making use of the parametric tool inside Autocad.
RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
The problem with integration and mohrs area theorems, the point of zero-slope has to be determined for the theorems to work and this is not always possible to calculate. Plotting any bending moment using AutoCAD is easy and accurate and I do not mind spending the time plotting the slope and deflection diagrams providing I get the right result.
I suppose I had better read-up on how slope diagrams are drawn and conjugate beams.
Thanks
RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
RE: Deflection and moment diagrams using AutoCAD
I have been reading Gere and Timoshenko and I attach one of their diagrams. I suppose I am trying to reverse the procedure shown in the figure.
Regards
RE: Deflection and moment diagrams using AutoCAD
How are you calculating the moments of your multi-span beam? Moment distribution?
If you can program in AutoLISP to draw a line from a function, why can't you write a subroutine that internally handles the integration of slope and deflection then just graphs them?
I find this problem fascinating from a purely academic perspective. In reality, like others have said, I would of course rather use Excel, RISA, paper.