Can anyone explain the values given in the report for design loads?
Is this based on max moment, shear or deflection?
I can't seem to replicate this calculation and it seems that it overestimates the equivalent load for deflection calculations.
Thanks!
It can be based on any of those limits, the common confusion is when users have deflection criteria that are more strict than the SJI tables, namely a total load deflection limit of L/240 which happens to be the program default, where the tables only have the Live Load L/360 limit. This wiki elaborates:
communities.bentley.com/.../2054.ramss-joists-faq.aspx
Answer Verified By: RFreund
OK, so the the total design load is the controlling equivalent load based on moment, shear and deflection?
How about the dead and live load?
Also I do have the deflection set at L/240 however when I model the deflection given the actual loading condition and use I determined by SJI method and the 0.85 reduction I find a deflection less than what RAM finds. Maybe I'm missing something here?
The program is just converting actual loads into equivalent loads and then looking up the design in a table. The capacity limits in the table are presumably for moments, though shear could be the control at short lengths or under high loads. For deflection, we prorate the tabulated L/360 limit from the table based on the user assigned deflection ratio. There is also a joist Allowable Stress Ratio factor in the Joist Criteria that similarly prorates the tabulated allowable loads. The Steel Beam manual, Section 4.2 (and 4.2.3 in particular) has details on this.