StochasticGroundMotionSimulation

Julia package to simulate response spectral ordinates via random vibration theory. The package also provides general functionality for working with Fourier amplitude spectra and duration models.

Package defines new custom types:

• FourierParameters: representing the parameters of the Fourier amplitude spectrum
• Oscillator: representing a single degree-of-freedom oscillator, and
• RandomVibrationParameters: defining methods/models used for random vibration calculations

The FourierParameters type is constructed from three components:

• SourceParameters: representing source properties, such as stress parameter, source velocity and density, etc
• PathParameters: representing the path scaling. This component is itself comprised of three components:
  • GeometricSpreadingParameters: defines the geometric spreading model
  • NearSourceSaturationParameters: defines the near-source saturation model, and
  • AnelasticAttenuationParameters: defines the anelastic attenuation
• SiteParameters: defines both the site amplification/impedance function and the site damping (via a kappa filter)

The package is developed in a manner to enable automatic differentiation operations to be performed via ForwardDiff.jl. This makes the package suitable for gradient-based inversions of ground-motion data, as well as inversions of published ground-motion models.

First, a working version of Julia needs to be installed. The relevant binary (or source code) can be downloaded from the Julia Downloads Page.

StochasticGroundMotionSimulation.jl is a registered package and can be installed directly from the package manager.

Within a Julia REPL session, access the package manager via ], and then at the pkg> prompt type (below the pkg> component is part of the prompt, so only the add ... portion is necessary).

pkg> add StochasticGroundMotionSimulation

Within a Julia session, bring the functionality of StochasticGroundMotionSimulation.jl into scope by typing (here the julia> component represents the prompt within a REPL session, within a text editor, simply type using StochasticGroundMotionSimulation):

julia> using StochasticGroundMotionSimulation

Aside from the documentation accessible from the links at the top of this page, descriptions of methods and types within the package can be accessed within REPL sessions (or within Juno).

Within, a REPL session, enter ? to access the help prompt. Then, type the relevant item. For example:

help?> FourierParameters

See CITATION.bib for the relevant reference(s).