Beam Element Section Does Not Render

Published 2013-06-12
WRITTEN BY:

Question

I created a structure of beam elements. All of the beams have the same section but some of the elements did not render the beam section. I made sure that the property was assigned to them as well. It also did not solve.
What is the problem?

Answer

This is a common problem and can be best described by the images below.

After creating a beam section, the most important property is the beam orientation vector, which basically specifies "which side is up?".

In the first attached image, you will see that the vertical beam did not render its section and the reason is because the orientation vector was specified as <0 0 1> which is perfectly parallel to the beam it self. This means it is still not clear how the T-beam section in this case of the vertical beam should be orientated (i.e. in which direction should the top of the T-section point?). The top of the T-section can not point in the same direction as the beam neutral axis since the section of a beam is perpendicular to its neutral axis.

For this beam, you should provide a vector that has a component that points away from the beam centre line, i.e. in the Y or X directions or any combination of both.

It becomes difficult to find one beam property for muliple beams that are orientated in different directions. Sometimes you will be forced to create more than one property, each referencing the same section property, but each with its own orientation vector.

I would always try to have as few properties defined as possible by specifying the orientation vector in such a way that it can serve as many beams as possible, but sometimes, as shown in the second image, it is not possible and then you need to create more.

BeamPropertyOrientation_2BeamPropertyOrientation

I think this is...