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  1. human909

    Footing uplift safety factor

    Agreed. "Factor of safety" is seemly the most obvious and clear margin of safety for a layman or even a engineer not wanting to do too much statistics. On the other hand it is close to the least suitable metric for gauging reliability and safety. That is why LFRD exists. And despite many in...
  2. human909

    Beam Reinforcement Calculation

    That is shifting the goal posts. Specifically "How do I calculate the required weld to ensure the section acts compositely?". No weld at the edges is required to ensure the section acts compositely. Sufficient connection to transfer vertical shear all that is required which is significantly...
  3. human909

    Beam Reinforcement Calculation

    Which is exactly what I have been saying. 😉 I'm not sure exactly what A-A1 is showing here. The curve reversal indicate you might be summing orthogonal loads or something.... I'm not sure can you explain the what it is showing and the direction? That is odd BA retired given that A-A2 is the...
  4. human909

    Beam Reinforcement Calculation

    I believe @Celt83 may have been loose with his language. I believe @Celt83 meant to say the shear flowing through the weld, or the shear demand on the weld is 0, or even the shear flow at the extremity of the side plates. All are zero. The shear flow at the web is not zero as you point out...
  5. human909

    Beam Reinforcement Calculation

    Glad to see you go back and look at your model. For what it is worth here is my model with discrete welds every 20mm. along with bolts every 20mm in the centre. n) It does show shear in the weld. But this is due to shear lag and their magnitudes 0.15kN are over order of magnitude, less than...
  6. human909

    Beam Reinforcement Calculation

    Hey smoulder! :) Thanks for taking a thoughtful look at my posts, which hasn't always been evident in other replies. Regarding your response. I agree entirely with your conclusions on my posts #28 doesn't fully expand to demonstrate a proof. And #62 doesn't contained the full depth of...
  7. human909

    Digital Seal and Signature

    That's the way I operate! But the strict legalities over signing/stamping aren't anywhere nearly as established in Aus as it is in the US/CAN. If my clients are manipulating my signed documents fraudulently then that is fraud and can be readily challenged. But IMO if that was to occur then I...
  8. human909

    Footing uplift safety factor

    I don't see why you would factor buoyancy up by 1.5. But that might depend on: -your assumptions regarding your buoyancy calculation -the requirements of local codes Load factors if LFRD is being being consistent should be base on the likely variance of the load. Both the dead load of the...
  9. human909

    Beam Reinforcement Calculation

    Agreed. A fantastic trick questions judging by the discussion in this thread. Though and certainly multiple ways to approach it. As many here have argued you don't even need to calculate it. The centroids are at the same point so sistering them would provide the same out come. No connection...
  10. human909

    Beam Reinforcement Calculation

    💙 THANK YOU! 💙 It has become quite circular and frustrating. But even then I've persisted because ultimately I have learnt a fair bit more about shear flow. You might have seen my grillage analysis that most people seemed to ignore. What was great about that was you could readily see shear...
  11. human909

    Beam Reinforcement Calculation

    This "diatribe" is relevant as it goes to the core of the original question. The longitudinal shear flow between the plates and the I beam would be zero. All you need to do to have them act as a compositive section is to sister them together. So bolts or spot welds at the centroid would be...
  12. human909

    Beam Reinforcement Calculation

    I agree that there is no difference in shear flow at all those points. Whether it is a solid piece or a piece with 3 plates. But then you jump to a false conclusion that you "require welds for side plates". When in fact you don't require any connection beyond a connection to transfer the cross...
  13. human909

    Beam Reinforcement Calculation

    Why are people trying to redefine basic geometric definitions like the first moment of area? (Q) Should we start redefining the second moment of area too? (I) These are mathematical geometric definitions.
  14. human909

    Beam Reinforcement Calculation

    There really shouldn't be any debate. Try calculating the strain between the plate and the I-beam web. Compare the two. See what results you get. If the strain is equal then how is force transferred? The side plates and I beam aren't act compositely. That is the case whether you weld the...
  15. human909

    Fire-Resistance Rating of Floor Assemblies in Industrial Buildings

    I would have thought that you could have a 'performance solution' or similar that could be suitable. I don't know your fire codes but that is how we normally do it for industrial structures including mills etc. Eg ensure suitable egress or other approaches. Fire compartmentalization between...
  16. human909

    Beam Reinforcement Calculation

    No, I've been waiting for him to show up. Maybe he is busy, or bored with the topic. He did provide input in the previous thread linked largely along similar lines of argument as what I have put forward.
  17. human909

    Cantilever Plate bending with UDL

    I find it remarkable so many people in this thread have spent the significant time discussing a 45degree shear lag when we have a UDL line load. I've been very confused by most of this.
  18. human909

    AS 2870 vs NCC

    This general discussion is a really interesting discussing. Unfortunately most Australian engineers (myself included) have quite limited idea on how exactly the law applies to them and I doubt that most involved in the whole approval process have a good understanding either. It likely isn't...
  19. human909

    Wind Load

    Thanks for providing closure. If I may I want to ask a question: I'm curious what percentage was your final wind load? Eg; vs your initial approach of half the wind load value "using the area of the top with a wind load using half the wind load value"? (My gut feel here is to not go below...
  20. human909

    Beam Reinforcement Calculation

    Agreed 100%. Sorry, I thought the point being made was fairly clear that calculating the total area C wouldn't be useful. You would need to calculate the Q area separately as you both point out. Calculating them both together gives you the NET shear flow of the top and bottom segments which...

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