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)