DisplacementControl Integrator

The DisplacementControl integrator is a static integration method that controls the displacement at a specific degree of freedom during analysis.

Description

This integrator is particularly suitable for:

  • Static analysis with prescribed displacement targets

  • Post-peak analysis in nonlinear structures

  • Cases where load-based control becomes unstable

  • Studies of structural behavior under specific displacement thresholds

  • Pushover analysis of structures

The DisplacementControl method applies load in a manner to achieve the target displacement increment at a specified node and degree of freedom.

Parameters

The DisplacementControl integrator requires the following parameters:

Parameter

Description

Default

Notes

node_tag

Tag of the controlling node

None

Required

dof

Degree of freedom at the node (1-ndf)

None

Required

incr

First displacement increment

None

Required

num_iter

Number of iterations desired

1

Optional

min_incr

Minimum step size allowed

incr

Optional, defaults to incr value

max_incr

Maximum step size allowed

incr

Optional, defaults to incr value

Usage Example

# Create a DisplacementControl integrator with basic parameters
integrator = fm.analysis.integrators.create_integrator("displacementcontrol",
                                                node_tag=3,
                                                dof=1,
                                                incr=0.01)

# Create a DisplacementControl integrator with custom step size limits
integrator = fm.analysis.integrators.create_integrator("displacementcontrol",
                                                node_tag=3,
                                                dof=1,
                                                incr=0.01,
                                                num_iter=5,
                                                min_incr=0.005,
                                                max_incr=0.02)