MinUnbalDispNorm Integrator

The MinUnbalDispNorm integrator is a static integration method that uses a minimum unbalanced displacement norm criterion to determine step size.

Description

This integrator is particularly suitable for:

  • Nonlinear static analysis with adaptive step size

  • Problems with varying degrees of nonlinearity

  • Cases where automatic step size control is beneficial

  • Analysis with potential numerical difficulties

The MinUnbalDispNorm method attempts to find a suitable load increment by minimizing the unbalanced displacement norm.

Parameters

The MinUnbalDispNorm integrator requires the following parameters:

Parameter

Description

Default

Notes

dlambda1

First load increment (pseudo-time step)

None

Required

jd

Factor for subsequent time steps

1

Optional

min_lambda

Minimum load increment

dlambda1

Optional, defaults to dlambda1 value

max_lambda

Maximum load increment

dlambda1

Optional, defaults to dlambda1 value

det

Flag to use determinant of tangent

False

Optional

Usage Example

# Create a MinUnbalDispNorm integrator with basic parameters
integrator = fm.analysis.integrators.create_integrator("minunbaldispnorm",
                                                dlambda1=0.1)

# Create a MinUnbalDispNorm integrator with custom parameters
integrator = fm.analysis.integrators.create_integrator("minunbaldispnorm",
                                                dlambda1=0.1,
                                                jd=3,
                                                min_lambda=0.05,
                                                max_lambda=0.2,
                                                det=True)