Sequential analysis

Definition, application

Two types of calculation can be combined in one analysis, where the results of a first calculation are used as initial state for the second calculation. It is for use cases where it is necessary to calculate for example stability or modal analysis after nonlinear analysis of structure.

Some use cases:

• Combine results of a nonlinear combination with some linear load cases, e.g. mobile loads or seismic
• Use the deformed state of a structure after a nonlinear analysis as initial state for a stability analysis
• Use the stress state of a structure after a nonlinear analysis as initial stress state for a dynamic analysis

Sequential analysis is supported only in Post-processing environment 'v16 and older' (32 bit version only).

Where to find it

Enable sequential analysis

In Project settings

• in the Basic data tab, select Post-processing environment 'v16 and older'
• in the Functionality tab, under Detailed and Nonlinearity, tick the option Sequential analysis.

Specific data input

Define calculation sequences by assigning a nonlinear combination to a linear Combination, a Stability combination or a Combination of mass groups.

Possibilities

Use cases	Description
NC in Combinations	A nonlinear combination is combined as a load case in a standard Combination.
NC in Stability combinations	A stability analysis is performed on a Stability combination using the deformed state from the nonlinear combination as initial state.
NC in Combinations of mass groups	A modal analysis is performed on a Combination of mass groups using the stress state from the nonlinear combination as initial stress state.
Combination in NC	A nonlinear calculation is performed using the content of a standard combination generated by linear construction stage analysis.

Running the calculation

In general, run the final target calculation. SCIA Engineer will determine the dependencies due to sequential analysis settings and run all necessary pre-requisite calculations before running the final calculation.

Example:

• in case a stability combination uses a nonlinear combination as initial deformed state
• run the stability analysis
• SCIA Engineer will first run the pre-requisite nonlinear calculation and then the requested stability analysis

Results

There is no particular steps that are required for results output from a sequential analysis.

There are however a few restrictions for specific types of sequential analysis.

For sequential analysis NC in Combinations, only the following types of results are supported

• Beams
  • Internal forces on beam
  • Deformations on beam
  • Relative deformations
  • Member stress
  • Connection forces
• 2D Members
  • Displacement of nodes
  • Member 2D - Internal forces
  • Member 2D - Stresses

(e.g. support reactions and storey results are not supported for that type of analysis)