ArcLength Integrator

The ArcLength integrator is a static integration method that follows the equilibrium path using the arc length method.

Description

This integrator is particularly suitable for:

• Post-buckling analysis of structures

• Problems with snap-through or snap-back behavior

• Tracing complex load-displacement paths

• Cases where load or displacement control fails

• Highly nonlinear structural problems

The ArcLength method uses a constraint equation based on the arc length along the load-displacement path, allowing it to navigate both load and displacement reversals.

Parameters

The ArcLength integrator requires the following parameters:

Parameter	Description	Default	Notes
s	Arc length	None	Required
alpha	Scaling factor on reference loads	None	Required

Usage Example

# Create an ArcLength integrator
integrator = fm.analysis.integrators.create_integrator("arclength",
                                                s=1.0,
                                                alpha=0.1)