shear center

[a126z]

When using beam units in ABAQUS, you have to define the shear center. How to find this shear center for a very complex section? Is it possible to leave it undefined? (I've seen a lot of software in the forum, such as ShapeBuilder, where I imported a complex circular section and ended up with a circle in the software, which doesn't meet the requirements).
The section is shown in the figure below.

 

[rb1957]

it'll be very difficult to get accurate results with a single 1D element with that sort of complicated loading.

I think if you don't define anything for the shear center then it is assumed to be at the origin (or maybe the centroid) ?
The clue will be in the manual which will define the position of the shear center with respect to some other feature of the section (the co-ord origin, the centroid of the section, ...).

I'm confused by the resultant ... I'd've expected units as kN (not kN/m) ... the applied loads can be kN/m, where distance is measured around the circumference.
Possibly distance is "out of plane" (like along the fusleage) and the detail loads are kN/m^2 ?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[a126z]

The unit of loading is KN/m, and the form of force is not consistent with Fig. Only the cross-section form is shown in Fig. I want to simulate this cross section by B31, is there any way to get the shear center of this cross section?

 

[rb1957]

yes (of course) ... it is quite an involved calc, you can find it in most texts, like Bruhn; you need the details of the section (not a "cartoon").

It is probably reasonable to guess it is the center of the circle, however that would be defined. Read the manual.

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.

 

[FEA way]

Abaqus has so-called meshed beam sections where you draw the cross-section, mesh it, use the *BEAM SECTION GENERATE procedure and get the properties from the .bsp file.

 

[a126z]

Thank you very much for your advice, my problem is solved!