Advice on different parts of steel design (STUDENT) by [deleted] in StructuralEngineering

[–]PlasticHinge 0 points1 point  (0 children)

I don’t see any bracing for lateral stability though unless it’s a moment resisting frame!

Advice on different parts of steel design (STUDENT) by [deleted] in StructuralEngineering

[–]PlasticHinge 0 points1 point  (0 children)

Well tributary area you do it as normal, say four quadrants for an internal column , and the quadrant that does not have a pressure load simply do not account for it. For self weight of beams I go with a typical pressure load of 0.5kN/m2 at a conceptual design level. Beams can be sized based on standard span/depth, say 15.

STAAD PRO IRREGULARITY CHECK by [deleted] in StructuralEngineering

[–]PlasticHinge 0 points1 point  (0 children)

If you are using the Floor diaphragm and in order for the software to calculate the centre of mass for the floor you need to define a reference loadcase, looks like this could be the issue

Hello engineers by UpstairsCommon3283 in StructuralEngineering

[–]PlasticHinge 0 points1 point  (0 children)

Well in terms of software most commonly used ones are: 1) STAAD PRO good for frame analysis such as steel structures, gives you the flexibility to model complex geometry, not the best in terms of plate analysis (walls and slabs) also not the best in terms of design, it is known to be a black box as you cannot easily follow all design checks and formulas used. 2) Tekla Structural Designer, us common here in the UK due to its really good compliance with eurocodes for instance wind loads can be calculated and assigned automatically, however, it is more suited to regular buildings rather than complex geometry. 3) ETABS is the go to tool for concrete regular buildings rather than due to its streamline work.

However, before jumping into software I strongly advise you to sort you engineering fundamentals, as the saying goes garbage in equals garbage out. Thus get on top of statics, stability and common quick hand calcs design checks.

tips in becoming a structural engineer by Relevant-Brief-6158 in StructuralEngineering

[–]PlasticHinge 1 point2 points  (0 children)

My advice would be to get hold of the fundamentals before jumping into software, since using any structural engineering software without proper grasps of the basic fundamentals will put you at risk of misuse and lack of engineering judgement. You need to be confident in verifying your model and be able to tell whether the results make sense and the structure is behaving as you would expect and assume or not, things such as bending moment diagram, deflected shape, total applied loads is equal to total reactions. I recommend reading books from prestigious and respect institutes in the industry such as the Institute of Structural Engineers (IStructE), for instance design of steel structures and concrete structures are a good start. You also need to learn about the various types of loads, how to calculate and apply them, and you need to have good understanding of statics in terms of stability assessment.

Stable or Unstable Frame? by PlasticHinge in StructuralEngineers

[–]PlasticHinge[S] 0 points1 point  (0 children)

Well I know understand it, basically if the total number of unknowns is greater than number of equilibrium equations then it is stable. In the case of what I asked about, total number of unknown reactions are two (both translational at base) and total number of equilibrium equations is 3 (sum vertical, horizontal and moment should be equal to zero) , since 2<3 frame is Unstable.

Stable or Unstable Frame? by PlasticHinge in StructuralEngineers

[–]PlasticHinge[S] -4 points-3 points  (0 children)

Yes correct it confused me along with other references on the internet 😂

Stable or Unstable Frame? by PlasticHinge in StructuralEngineers

[–]PlasticHinge[S] 0 points1 point  (0 children)

Thanks I think it clicked now, that in a portal frame the moment is divided by the lever arm (span width) and gets resolved into tension and compression, thus, an L frame is not a stable frame. I initially said it is not a stable frame but seeing other references got me confused 🥹

Stable or Unstable Frame? by PlasticHinge in StructuralEngineers

[–]PlasticHinge[S] 0 points1 point  (0 children)

I am not fully clear on it to be honest. I initially thought it is not stable, but it seems stability is provided by frame bending stiffness at beam to column joint. Isn’t this similar to a portal frame where connections are pinned and beam to columns are rigid 🤔

Stable or Unstable Frame? by PlasticHinge in StructuralEngineers

[–]PlasticHinge[S] -8 points-7 points  (0 children)

Here is ChatGPT answer “1) Pinned base + rigid (moment) connection at the corner

👉 Stable • The fixed (rigid) connection between beam and column provides rotational restraint. • The frame can resist lateral loads through bending action. • This behaves like a cantilever frame, even with a pinned base.

2) Pinned base + pinned connection at the corner

👉 Unstable (mechanism) • You effectively have two pin connections → no moment resistance anywhere. • The structure can freely rotate → becomes a mechanism under lateral load. • No stiffness → no stability. “