For the structural analysis of 1D objects, you can use both members and member sets. While the use of members is generally sufficient for cross-section checks, member sets are often required for stability analyses. The importance of member sets for timber design is explained here.
Using Member Sets
The use of a member set is particularly necessary for stability analyses to ensure that the critical load for the lateral-torsional buckling analysis is determined correctly or that the entire member length is considered as the effective length: For members, only the respective member length is considered. Therefore, the design of a structural component across members is usually only possible using member sets. The nodes between the members of a member set can be considered as intermediate nodes in the Effective Lengths dialog box.
As an alternative, you can model straight, uniform structural components as continuous members with nodes on members. The stability analysis can then be performed even without member sets.
Designing Members or Member Sets
You can design members that are part of a member set either as individual members or as part of the member set. To avoid conflicting entries and results, the associated members are automatically deactivated for timber design when designing as a member set. If you specify the members for design, the parent member set is deactivated accordingly. You can check this rule in the Objects to Design input table by reviewing the list of objects in the “Not Valid / Deactivated” column.
After the design, a note is displayed in the Not Valid / Deactivated result table (see the chapter Overview) for all members that were designed using a member set and are therefore deactivated. Similarly, member sets are marked there with a note if they were not designed.
Assigning Design Properties
You can assign the same design specifications to a member set as to a single member. Based on the restriction that a member set and a single member cannot be designed simultaneously, after activating the design properties of a member in the member set, a query appears asking whether the remaining members should also be designed.
When you assign design properties to a member set, all members contained within it receive the Via parent member set design property, and the design-related tabs for these members are hidden. This prevents conflicting specifications.
If no member set exists yet, you can create a new member set using the
button in the “Design Properties” section. Use the
button to edit the selected member set.