G.15.2 Member Load
Three types of member loads may be applied directly to a member of a structure: uniformly distributed loads, concentrated loads, and linearly varying loads (including trapezoidal).
Uniform loads act on the full or partial length of a member. Concentrated loads act at any intermediate, specified point. Linearly varying loads act over the full length of a member. Trapezoidal linearly varying loads act over the full or partial length of a member. Trapezoidal loads are converted into a uniform load and several concentrated loads.
Any number of loads may be specified to act upon a member in any independent loading condition. Member loads can be specified in the member coordinate system or the global coordinate system. Uniformly distributed member loads provided in the global coordinate system may be specified to act along the full or projected member length. See G.4.1 Global Coordinate System to find the relation of the member to the global coordinate systems for specifying member loads. Positive forces act in the positive coordinate directions, local or global, as the case may be.
Uniform moment may not be applied to tapered members. Only uniform load over the entire length is available for curved members.