# Talk:Grid bracing

This review is transcluded from Talk:Grid bracing/GA1. The edit link for this section can be used to add comments to the review.
Nominator: David Eppstein (talk · contribs) 01:09, 15 November 2024 (UTC)
Reviewer: Noleander (talk · contribs) 19:57, 24 January 2025 (UTC)

GA review – see WP:WIAGA for criteria

Is it well written?
A. The prose is clear and concise, and the spelling and grammar are correct: 

B. It complies with the manual of style guidelines for lead sections, layout, words to watch, fiction, and list incorporation: 

Is it verifiable with no original research, as shown by a source spot-check?
A. It contains a list of all references (sources of information), presented in accordance with the layout style guideline: 

B. Reliable sources are cited inline. All content that could reasonably be challenged, except for plot summaries and that which summarizes cited content elsewhere in the article, must be cited no later than the end of the paragraph (or line if the content is not in prose): 

C. It contains no original research: 

D. It contains no copyright violations nor plagiarism: 

Is it broad in its coverage?
A. It addresses the main aspects of the topic: 

B. It stays focused on the topic without going into unnecessary detail (see summary style): 

Is it neutral?
It represents viewpoints fairly and without editorial bias, giving due weight to each: 

Is it stable?
It does not change significantly from day to day because of an ongoing edit war or content dispute: 

Is it illustrated, if possible, by images?
A. Images are tagged with their copyright status, and valid non-free use rationales are provided for non-free content: 

B. Images are relevant to the topic, and have suitable captions: 

Overall:
Pass or Fail: 


### Review by noleander
Starting this now.   I have not done a GA review in awhile, so if I make a mistake in the formatting, feel free to fix it.  Noleander (talk) 19:57, 24 January 2025 (UTC)

Overall, looks to be in  great shape.  I don't foresee any issues getting GA status.
Is this topic considered part of graph theory? If so, that probably should be mentioned in first couple of sentences.  Wait, I see that Structural rigidity is a part of combinatorics, so that is the primary area of math for this article.  Never mind on the graph theory suggestion.... but maybe mention "combinatorics" in the first couple sentences?  That area of study is pretty recognizable (I had no idea "Structural rigidity" was a thing, but combinatorics is a common word).
These first few questions, and your last bullet point suggesting a merge, give me a hint that something important has gotten lost here and maybe could better be emphasized in this article. This is on a specific problem, not a broad research specialty. That specific problem forms a bridge between graph theory (in combinatorics) and the design of cross-braced structures (in mechanical engineering), as part of the more general theory of structural rigidity. It is neither purely in combinatorics nor purely in engineering design. It is part of a broader area of study of mathematical models of problems in rigidity, structural rigidity. Was there something about the start of the lead sentence, "In the mathematics of structural rigidity..." that gave you some other idea than that? —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Is is possible to list some real-world applications of this?  Besides architecture, maybe something like scaffolding?
Again, this is not an article in engineering design. It is an article on a mathematical problem that models some issues in engineering design. Anyone who has played with building blocks or houses of cards might understand some of the issues here. I also have some personal experience with this problem in connection to safe disassembly and reassembly of bookshelves braced only by their ties to walls. But anything like that could only really be added if we had reliable sources discussing this specific problem in the context of those specific applications. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Seems like airplanes and space stations would really benefit from the "Minimal bracing" since they need to keep weight down to a minimum. But I doubt there are any sources that discuss that.
True, but also this article is on a very specific problem involving the rigidity of two-dimensional rectangular-grid bar-and-joint frameworks, and those kinds of structures are three-dimensional, not rectangular, and are in large part made rigid by their surfaces and not merely by their support beams. A curved surface can actually be quite rigid in certain directions: you might think of a sheet of paper as being very floppy, but curve it and (unless you crease or crumple it) it will not bend in the direction perpendicular to the direction you have already bent it. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
The structures here are 2D and rectangular (4-sided cells);  This seems like a subset of more general problems.  Are there analogous math investigations for (a) 3D; and (b) non-rectangular (e.g. a hexagonal 2D layout; and the problem is to insert additional braces within the hexagons?  If there are similar math topics for 3D and/or non rectangular, maybe mention them in passing?
There are general problems, but this article is on a specific problem, the problem where the structures are 2d and rectangular. If we have appropriate sources for them, we could have an article on those more general problems. And in fact we do have some such articles; for instance, Rigidity matroid is about the rigidity of bar-and-joint frameworks that are not rectangular and may be in arbitrary dimensions. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Any association with geodesic domes, which consist of mostly hexagons & some pentagons (that have been subdivided into 6 or 5 triangles, respectively)?
Again, those are not rectangular structures and are therefore beyond the scope of this specific article. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Photo of collapsed building/balconies is great.   How about adding a picture of a building that illustrates great bracing?  e.g. Bank of China Tower (Hong Kong) or John Hancock:

Also, this article is on a specific mathematical model of cross-bracing, not about engineering design and not about cross-bracing in general. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Text points out that adding a brace in _every_ cell is overkill.  Are there any photos of a building or object that has sparse/minimal bracing?  Not a show stopper if article does not have such a pic, but would be helpful to reader to see it.
I don't know of such photos. Part of the issue is that minimality is not necessarily as important as aesthetics and regularity of design. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Consider adding a pic of Tensegrity if it is relevant
I'm not convinced that it is. It is related, certainly. Especially, the tension bracing section is closely related to the idea that one can have structures where some elements are purely under compression and some are purely under tension, and that the compression elements do not need to even touch each other. But here the grid part of the structure is assumed to be rigid both under compression and under tension, and in the main version the same is true for the braces, unlike the tension elements in tension bracing. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Mechanical engineering & Structural engineering must have a HUGE amount of study & research on analogous topics in their world (e.g. building a cantilever bridge, or building a skyscraper, etc).  Perhaps find WP articles on that and put them in a  "See Also" section?  For example, I googled and found this random article " Seismic Performance Of Steel Grid Braced Steel Frame" [1] ... are there any WP articles that cover that  subject?   E.g. article Truss.  Or is Structural rigidity the article (which you already link to in 1st sentence) the analog article in the  Structural engineering universe?  I dunno, the Structural rigidity article looks like 99% math.  There must be a structural engineering article on this, but I cannot find it.
Structural rigidity is the main parent article on the mathematical study of analogous topics. Through it, these topics are connected both to other mathematical topics such as matroid theory, and other topics that are more purely mechanical engineering than mathematics. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
The name of this article is "Grid Bracing" and 1st sentence says it is a "problem", so I gather it is not broad enough to be a discipline or field or  area-of-study... rather it is a focused topic.  So there are not any books on the subject?  or classes with that name?  No big deal, just curious about the size/scope.   Is there a seminal article that established the study of "Grid bracing"?
I have used the main references that I know of as references in the article. They include entire sections or chapters of at least three books, but not entire books. The Bolker and Crapo 1977 reference is a research article and may be the seminal article for this topic. To say that explicitly I would need a source saying so. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Follow up to above point:  Should this article be merged with "Structural rigidity"?  That article is rather small; and if Grid Bracing is within the study of Structural rigidity, maybe readers would be better served with them consolidated?    A standalone article on Grid Bracing makes more sense if Grid Bracing has some significant sources that talked about it as  distinct area of study, but the sources don't seem to treat it that way.    Contrast with famous "problems" in the realm of combinatorics/graph theory such as the Euler 7-bridge problem, the knapsack problem, or the traveling salesman problem: these are significant, and have lots of sources devoted exclusively to them; and they deserve their own articles.  Is Grid Bracing in that same league?
Short answer: No. It is a subtopic of structural rigidity but we have many other subtopics of the mathematics of rigidity that are at least as notable: rigidity matroid, Laman graph, Flexible polyhedron, Steffen's polyhedron, Cauchy's theorem (geometry), Cayley configuration space, Graph flattenability, etc. There is no more reason to merge this one than any of the others, and merging them all would create an unfocused monster article. —David Eppstein (talk) 01:14, 27 January 2025 (UTC)
Noleander (talk) 20:03, 24 January 2025 (UTC)
All right, I read your responses and they make sense.  I checked image copyrights, and they are good.  Did a spot check on a few sources, and it all looks great.  GA is "pass"  Noleander (talk) 04:27, 28 January 2025 (UTC)

Thanks! —David Eppstein (talk) 07:17, 28 January 2025 (UTC)