RAM Structural System Help

Positive Loads, Negative Loads, and Skip Loading

On the outputs, gravity loads are referred to as Positive or Negative. A Positive load is a downward acting load while a Negative load is an upward acting load. For simple span beams, Positive loads create beam reactions which become Positive loads on the supporting members. However, Positive loads on a cantilever create uplift on the backspan support, the reaction of which becomes a Negative load on the supporting member. Negative loads only occur as a result of cantilevered beams or from user‑defined negative loads. The program keeps track of Positive and Negative loads independently.

On the outputs, moments and reactions are labeled Maximum Positive and Maximum Negative. If there is no Negative value, it is listed as 0.0 or not shown at all. If there is no Positive value, it is listed as 0.0 or not shown.

As required by Code, when a beam is cantilevered at one or both ends RAM Steel Beam Design skip loads the Live load on adjacent spans and alternating spans such as to create the maximum moments, deflections, and reactions. Not only does RAM Steel Beam Design skip load the Live loads, it applies the Positive and Negative loads on alternating spans such that the worst conditions are calculated.

Roof Live Loads are also skip loaded.

RAM Frame does not skip load the Live loads except when calculating the reactions on the frame members from gravity members with cantilevers.