Modeling Curved Beam Bending 9

[ZhiMing]

Hi guys,

I am trying to model the behavior of a carbon fiber/epoxy curved beam with a 90 degree bend subjected to an opening moment at its ends. I am doing this with SR4 shell elements in Abaqus standard. But the resulting stiffness (i.e., moment/curvature) of the model always comes out to be 2 to 3 times higher than my experimental results. I am wondering if anyone has done something similar and can give me a hint. Am I even using the correct element type? Many thanks.

ZhiMing

 

[GregLocock]

Let me guess that you have a C cross section. The chances are that non linear effects in the warping of the flanges are softening your real results.

Cheers

Greg Locock


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[SWComposites]

Please describe in detail how you are running the test (loading, supports, dimensions, etc), the thickness of the laminate, and the maximum deflection.

Then please describe in detail the loads and boundary conditions on your FEM, the material properties used, the solution type (linear, nonlinear).

If the deflection is large, depending on the test configuration, the loading points and moments can change.

 

[prex]

If your beam is a pipe, then the stiffness is critically determined by second order effects (ovalization). Only an analysis with geometric non linearities turned on can account for this.
A similar effect, with variable magnitudes, will take place with other shapes (hollow square, where the sides will bend, but also open profiles, etc.).

prex

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[btrueblood]

3 really good answers, all of which are deserving of a little pink star.

 

[btrueblood]

Fine, I'll deal them then. Putz.