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RAM SS- Remove deflection failure report for cambered beams

When the camber of a beam brings the deflection criteria within parameters, the option to turn off flagging them as failed in report would be greatly appreciated. 

In a large job with several repetitive floors with cambered beams, there can be hundreds of flagged failures and is harder to weed out which beams are actually failing. 

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  • If the Camber brings the deflection into conformance with the deflection limits, the program does not flag the beam as failing deflection. If the program is flagging the beam as failing the deflection criteria, the beam is failing.

    I think the issue here is understanding how the program deals with camber, and why.

    In the reported values of deflection and for the values compared with the deflection limits, only Net Total includes the effects of camber. For an unshored composite beam, four values of deflection are pertinent.

    • The Initial deflection is that due to dead load on the bare (precomposite) beam. This value is used to calculate the required camber. Commonly, there is no limit specified for Initial Deflection, but a limit can be specified there as a means to limit the amount of Camber that will be required.
    • Post-composite Live Load deflection is an important consideration because of the impact that it can have on interior partitions, doors and windows, interior finishes, and connection of exterior finish to the structure, all of which need to accommodate the range of deflection of the beam. Camber is not subtracted from this value because the pertinent condition is the range of deflection as it is loaded and unloaded, not on the beam’s lowest point when loaded; camber doesn’t change the range of motion that needs to be accommodated. The common limit for this is L/360; often perimeter beams will also include an absolute limit (e.g., 0.5”) based on the ability of exterior finish to absorb the up and down movement.
    • Post-composite Superimposed deflection is an important consideration for the same reasons as for Live Load, and Camber is not subtracted from this value for the same reasons. The common limit for this is L/240.
    • Net Total deflection is the only value reduced by Camber. This value is a measure of the beam and slab’s flatness in its final configuration, so Camber is an important part of that resulting configuration. This value tells you the beams true condition in its final loaded state, and ideally that should be as flat as possible. The common limit for this is L/240.

    For a noncomposite beam three values are pertinent, Dead, Live and Net Total. For the same reasons given above, Camber is only subtracted from the Net Total value.

    So cambering only helps when considering the acceptability of the beam's final position: is it flat enough. Cambering doesn't help you with Live Load or post-composite deflection because those aren't concerned with flatness, they are concerned with range.

  • Yes, I am in agreement and familiar with the procedure and reporting of the deflections and camber. There are firms that apply deflection criteria to the initial deflection c to help limit excessive ponding of concrete in bays.  When designed properly for vibrations, the post composite SDL and LL limits are typically met and not part of the flagged deflection failure.    Marking beams to a different deflection criteria is cumbersome, and time consuming.  Beams with different deflection criteria are not easily viewed, especially on a large floor plan.

    Just requesting an option for an extra line in the report for "Initial Deflection including camber" and a toggle to flag the deflection failure if it fails Initial Deflections excluding camber.

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  • Yes, I am in agreement and familiar with the procedure and reporting of the deflections and camber. There are firms that apply deflection criteria to the initial deflection c to help limit excessive ponding of concrete in bays.  When designed properly for vibrations, the post composite SDL and LL limits are typically met and not part of the flagged deflection failure.    Marking beams to a different deflection criteria is cumbersome, and time consuming.  Beams with different deflection criteria are not easily viewed, especially on a large floor plan.

    Just requesting an option for an extra line in the report for "Initial Deflection including camber" and a toggle to flag the deflection failure if it fails Initial Deflections excluding camber.

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