For each envelope, Substructure selects the maximum and minimum values from all corresponding load groups. For example, the strength load group will include the maximum and minimum values among all strength load combinations.
Substructure generates following combinations:
AASHTO LRFD
- Envelope Service (for all service limit states)
- Envelope Strength (for all strength limit states)
- Envelope Extreme Event (for all extreme event limit states except those in Extreme Event Seismic)
- Envelope Fatigue (for all Fatigue limit states)
- Envelope Extreme Event Seismic (for all Extreme Event Seismic limit states)
AASHTO Standard with at least one load factored group selected.
- Envelope Service (for all service load groups without overstress consideration)
- Envelope Strength (for all strength/factored load groups)
- Envelope Seismic (for all seismic load groups)
AASHTO Standard with only service load groups selected.
- Envelope Service N/O (no overstress consideration)
- Envelope Service W/O (with overstress reduction)
Note: Substructure does not consider the specific combinations for column design when generating the envelope in AASHTO Standard mode, because the column combinations are only used for column design. In addition, column design uses the column combinations, not envelopes.
