The pattern live-load factor (Pllf) is intended to account for variability in the live-load arrangement on a structure. Since live-load pattern is not automated, Pllf approximates its design effect.
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Pattern live-load factors may be assigned to individual elements using the Design > Steel Frame Design or Concrete Frame Design > View/Revise Preferences command, as shown in Figure 1:
Example
The maximum positive midspan design moment induced by uniform dead- and live-load application would be calculated as follows:
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