aothms
commented
8 months ago I think it's applaudable to try and improve these definitions. I'm ultimately not the one who will be deciding on this. But here are some random thoughts from my side,
The ambiguity between load bearing and non-loadbearing exists on various building element definitions. Best address them all at once. I think it relates to two aspects: one being decorative elements (although this would apply more to columns / pilasters then beams), but also the fact that multiple disciplines can have different perspectives on elements. E.g there can be a structural beam in the enginereering model and maybe some covering of that element in the architectural model where the covering is still modelled as a beam.
... structural member ...
Note that https://ifc43-docs.standards.buildingsmart.org/IFC/RELEASE/IFC4x3/HTML/lexical/IfcStructuralMember.htm is actually a class in our taxonomy, better not use that wording directly.
Your definition also is a bit more didactic on how such elements function within a structure as opposed to providing clarity on the context in which this element label should be applied within an IFC context.
trhyder
The definition of an IfcBeam requires revision to eliminate contradictory and subjective language. I will review each sentence of the definition, highlighting issues, and propose a revised definition at the bottom.
“An IfcBeam is typically a horizontal, or nearly horizontal, structural member that is capable of withstanding load primarily by resisting bending.”
This initial sentence could be enhanced by better explaining a beam's structural function and more completely addressing the forces and loads it resists. In addition, the wording “nearly horizontal” is an ambiguous phrase that lacks a definable limit, and also appears to be contradictory to the visual example provided on the same page that could be considered greater than “nearly horizontal”.
Even if there were a definable limit for "nearly horizontal", I can't think of a good enough reason for this to be in the definition. Is there an explicit reason for this or was it just pulled from ISO 6707-1?
“It may also represent such a member from an architectural point of view.” This sentence is vague and assumes a shared understanding of what constitutes an "architectural point of view." I think this sentence is not core to the definition and should be deleted.
“It is not required to be load bearing.” This sentence appears to be contradictory to its primary function and the extract from ISO 6707-1 (structural member for carrying load(s) between or beyond points of support). If there are exceptions to the primary function, they should be defined, but I can’t think of any situations where a beam is not bearing some type of load - am I missing something here?
In addition, it would be beneficial to include a description of the shape or profile characteristics, given these relate to both the structural performance and visual identification of a beam.
Taking into account the aforementioned issues, the definition could be better phrased as follows:
An IfcBeam is a structural member utilized in building and bridge structures to support loads perpendicular to its longitudinal axis. These loads encompass static structural loads, live operational loads, and environmental forces such as wind or seismic loads. IfcBeams are often classified based on their cross-sectional profile, including I-beams, H-beams, or rectangular beams. Different cross-sectional profiles vary in structural efficiency when distributing loads and resisting bending, shear, and other forces.