HHT Integrator

The HHT (Hilber-Hughes-Taylor) integrator is an implicit time integration method for dynamic analysis with controllable numerical damping.

Description

This integrator is particularly suitable for:

• Structural dynamics problems requiring numerical damping

• Cases where high-frequency noise should be filtered out

• Nonlinear dynamic analysis

• Long duration dynamic simulations

• Problems with stiff differential equations

The HHT method is an extension of the Newmark method that introduces controlled numerical damping while maintaining second-order accuracy.

Parameters

The HHT integrator requires the following parameters:

Parameter	Description	Default	Notes
alpha	Alpha factor	None	Required, controls numerical damping
gamma	Gamma factor	1.5 - alpha	Optional, defaults to 1.5 - alpha
beta	Beta factor	(2-alpha)^2/4	Optional, defaults to (2-alpha)^2/4

Usage Example

# Create an HHT integrator with only alpha specified (gamma and beta calculated automatically)
integrator = fm.analysis.integrators.create_integrator("hht", alpha=-0.1)

# Create an HHT integrator with all parameters explicitly defined
integrator = fm.analysis.integrators.create_integrator("hht",
                                                alpha=-0.1,
                                                gamma=0.6,
                                                beta=0.3025)