Frame vs Sumo: Pad Footing Design Workflow

When analysing a structure in Sumo or Frame, one or more bases and their respective load cases can be transferred to Pad Footing Design using the Design Links

The analysis type that’s performed in Sumo or Frame, and the loads considered play an important role in how loads are sent to Pad Footing Design. To illustrate the different possible outcomes, the following scenarios are considered:

Scenario 1: Performing a linear analysis in Frame or Sumo, considering Load cases and Load Combinations.

Sumo Linear loadcases and load combinations

Linear: Sumo or Frame – Load cases and combinations

When load cases and combinations are considered, Pad Footing will receive the individual load cases as well as combinations including load factors.

Scenario 2: Performing a linear analysis in Frame or Sumo, considering Load Combinations only.

Sumo Linear load combinations only

Linear: Sumo or Frame – Load combinations only

The Load combinations are received by Pad Footing with a load factor of 1. The loads have already been factored and the load doesn’t have to be factored again.

When performing a second-order analysis we can’t simply apply superposition to the load cases to determine the load combinations, since the second-order effects are determined iteratively and depend on vertical and lateral loads.

Scenario 3: Performing a second-order analysis in Frame, considering Load cases and Load Combinations.

Frame Second order loadcases and load combinations

Second order: Frame – Load cases and Load Combinations

A load factor is applied to the load cases. This load factor might be a strange value because it is a factor determined internally and is the multiple that takes the load case loads to the load combination load.

Scenario 4: Performing a second-order analysis in Frame, considering Load Combinations only.

Frame Second order load combinations only

Frame, considering Load Combinations only.

The loads have already been factored in; the resultant reactions are used for design (with a load factor of 1).

Scenario 5: Performing a second-order analysis in Sumo, considering Load cases and Load Combinations.

Sumo Second order loadcases and load combinations

Sumo, considering Load cases and Load Combinations

If a second-order analysis is done in Sumo, the load factors exported to Pad Footing are all equal to 1, that is the loads have already been factored in Sumo.

Scenario 6: Performing a second-order analysis in Sumo, considering Load Combinations only.

Sumo Second order load combinations only

Sumo, Second-order Load Combinations only

The loads have already been factored in; the resultant reactions are used for design (with a load factor of 1).