## Name

stage — Analysis stage block

## Synopsis

stage id
attributes
end

## Description

The stage command specifies the analysis stage identified by id (a positive and unique integer number), which must be referenced by an analysis case. An analysis stage contains ingredients such as initial conditions (if the stage is the first stage), boundary conditions, and solution strategy parameters. The analysis type is specified within the case command, as it is not possible to select the analysis type on a per-stage basis.

## Attributes

The attributes enumerated in this section pertain to most types of analyses and concern the specification of initial conditions, boundary conditions, and constraints. Solver-specific attributes are explained in the chapter Solvers. The attributes are a subset of the attributes that can specified inside an analysis case without stages.

atemperatures id [sfactor s|sfunction "function_string"]

Specifies the ambient temperatures set id to be included for certain types of analysis, like heat analysis.

In linear analysis, the optional parameter sfactor specifies a scale factor s by which the set is multiplied, the default value being 1.0.

In nonlinear direct analysis and in incremental analysis, the set is scaled by the load factor (static analysis) or by the time (dynamic analysis). The optional parameter sfactor specifies an additional scale factor s by which the set is multiplied, the default value being 1.0. Alternatively, the optional parameter sfunction specifies a function which is being evaluated at each load or time increment and by which the set is multiplied.

component name type "argument" [sfactor s|sfunction "function_string"]

Specifies a component to be used in the current analysis stage. Components are extensions to B2000++. They implement specific natural boundary conditions, essential boundary conditions, initial conditions, or sets of constraints.

The name and type parameters are used to identify the component[7], while the argument parameter is given to the component at the start of the analysis (stage).

In linear analysis, the optional parameter sfactor specifies a scale factor s by which the values returned by the component are multiplied, the default value being 1.0.

In nonlinear direct analysis and in incremental analysis, the values returned by the component are scaled by the load factor (static analysis) or by the time (dynamic analysis). The optional parameter sfactor specifies an additional scale factor s by which the values returned by the component are multiplied, the default value being 1.0. Alternatively, the optional parameter sfunction specifies a function which is being evaluated at each load or time increment and by which the values returned by the component are multiplied.

dof_init|dofdot_init id

Specifies the initial conditions set id for the current analysis stage. The stage must be the first stage.

ebc id [sfactor s|sfunction "function_string"]

Adds the essential boundary conditions set id to the current analysis stage. Note that essential boundary conditions are not cumulative, i.e. if several essential boundary condition sets are specified, all values of common degrees-of-freedom must be equal.

In linear analysis, the optional parameter sfactor specifies a scale factor s by which the set is multiplied, the default value being 1.0.

In nonlinear direct analysis and in incremental analysis, the set is scaled by the load factor (static analysis) or by the time (dynamic analysis). The optional parameter sfactor specifies an additional scale factor s by which the set is multiplied, the default value being 1.0. Alternatively, the optional parameter sfunction specifies a function which is being evaluated at each load or time increment and by which the set is multiplied.

field_transfer id

Adds the field_transfer set id to the current analysis stage. Note that a field_transfer set with an id of 0 is automatically added to all analysis cases and stages.

Alternatively, several or all field_transfer sets may be specified:

field_transfer ilist field_transfer all

It is required to specify a constraint method other than the default reduction method for which the accuracy of the calculated solution cannot be always ensured when field_transfer conditions are active. See also Imposing Constraints.

join id

Adds the join set id to the current analysis stage. Note that a join set with an id of 0 is automatically added to all analysis cases and stages.

linc id

Adds the linear constraints set id to the current analysis stage. Note that a linc set with an id of 0 is automatically added to all analysis cases and stages.

nbc id [sfactor s|sfunction "function_string"]

Adds the natural boundary conditions set id to the current analysis stage. Natural boundary conditions are cumulative, i.e. if several natural boundary condition sets are specified the resulting natural boundary condition for id is the sum of all natural boundary condition sets multiplied by their respective scaling.

In linear analysis, the optional parameter sfactor specifies a scale factor s by which the set is multiplied, the default value being 1.0.

In nonlinear direct analysis and incremental analysis, the set is scaled by the load factor (static analysis) or by the time (dynamic analysis). The optional parameter sfactor specifies an additional scale factor s by which the set is multiplied, the default value being 1.0. Alternatively, the optional parameter sfunction specifies a function which is being evaluated at each load or time increment and by which the set is multiplied.

temperatures id [sfactor s|sfunction "function_string"]

Specifies the temperatures set id to be included for certain types of analysis, like thermal stress analysis.

In linear analysis, the optional parameter sfactor specifies a scale factor s by which the set is multiplied, the default value being 1.0.

In nonlinear direct analysis and in incremental analysis, the set is scaled by the load factor (static analysis) or by the time (dynamic analysis). The optional parameter sfactor specifies an additional scale factor s by which the set is multiplied, the default value being 1.0. Alternatively, the optional parameter sfunction specifies a function which is being evaluated at each load or time increment and by which the set is multiplied.

title '...text...'

Optional title describing the analysis stage.

[7] Under this identifier, the component is registered.