Answer:
For open structures that consist only of members, such as lattice towers, the load acts only on the member cross-sections.
To apply area loads such as snow or wind to an open structure, select Load Wizards → Member Loads from Area load to create a new area load. Under the Geometry tab, select "Empty, on members only" for the Area of load application.
The area load can be displayed on individual members by right-clicking the load and selecting Display separately.
