Load Vs deflection curve for simply supported beam under point load at centre
Load Vs deflection curve for simply supported beam under point load at centre
(OP)
I have performed collapse analysis for a simply supported tubular beam by applying load at centre. And I am getting load Vs deflection curve at mid point as per attachment. Can anyone explain what is the reason for this type of behavior.






RE: Load Vs deflection curve for simply supported beam under point load at centre
It is not clear why the curve continues to LF of about 90 and deflection of about 27cm. I would have expected the beam to collapse when the plastic hinge reached about 2*Fy if the beam was truly simply supported, i.e. pin and roller. With such large deflections, is it possible you were getting axial tension in the specimen? What was the span length?
BA
RE: Load Vs deflection curve for simply supported beam under point load at centre
RE: Load Vs deflection curve for simply supported beam under point load at centre
Hinge support on both ends
RE: Load Vs deflection curve for simply supported beam under point load at centre
If the point of load application prevents horizontal movement of the specimen, you must have a roller support at both ends.
BA
RE: Load Vs deflection curve for simply supported beam under point load at centre
at some stage i'd expect the load/displacement curve to "kick over" and give large displacements for small changes in load.
I assume the testpiece didn't fail in the test.
have you tried to FEA the test ? if both ends of the beam are pinned, so the beam cannot contract as it bends, then that'll induce tension in the beam.
another day in paradise, or is paradise one day closer ?
RE: Load Vs deflection curve for simply supported beam under point load at centre
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RE: Load Vs deflection curve for simply supported beam under point load at centre
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Load Vs deflection curve for simply supported beam under point load at centre
As the load and deformation rises the beam will get tension force and then at some point 'change' to more cable like behavior
and the load can be raised up much more
This numerical test is good to test a program on nonlinear capabilities ....