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I-Simpa User Guide

Release version of I-Simpa: 1.2.3 Release version of SPPS: 2.2.1

info Note that illustration may referred to previous versions of I-Simpa.

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• means an tip that can be useful for users
• is just an information
• refers to an important information, which must be read with attention by users.

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Introducing I-Simpa

I-Simpa presentation

I-Simpa is a graphical user unterface (GUI) developed to host three-dimensional numerical codes for the modeling of sound propagation in complex geometrical domains.<br > Although I-Simpa is well adapted for energetic models (ray-tracing, sound-particle tracing, theory of reverberation…), it can be extend to use ondulatory approaches.<br>

I-Simpa alone is not a calculation software, but is equivalent to a pre and post-processor for acoustic codes. One or more numerical codes must be added in order to obtain a fully functional system. At the present time, I-Simpa is delivered with two codes (TCR and SPPS,see information here).

Classical applications are room and building acoustics, environmental noise and industrial noise, but it can be easily extend to other applications concerning the sound propagation in 3D environments (interior of vehicle, sound in cavities…).

The main concepts of I-Simpa are:

• a functional GUI: elements and components are organized in tree structures, to easily access to all information, parameters and properties. Many features are proposed for helping users…
• an ‘open’ system: all information and data are organized in spreadsheets that can be displayed, exported, copied…
• an ‘open’ software:each user can integrate its own numerical propagation code, develop its own functionalities within the interface for its own applications… All have been done in order you can extend I-Simpa easily.

I-Simpa has been initially developed as a research tool (i.e. for research laboratories), but can also be a very efficient tool for a professional or commercial use.

Functionalities

• Scene geometry:

  • import files with extension: 3DS (3D Studio), STL (stereolithography), PLY (Stanford) and POLY (TetGen)
  • integrated tools for model corrections and repairs during importation
  • algorithm for model approximation model error detection
  • manual design of parallelepipedic model

• Material properties:

  • import file from CATT-Acoustic™ and Odeon room acoustics software
  • integrated ‘reference’ database (can not be modified by users)
  • integrated ‘users’ database (can be modified by users)
  • material classification in groups and sub-groups
  • copy/paste of materials between database, groups and sub-groups
  • definition of acoustic parameters (absorption, transmission loss, scattering, scattering reflection law) by frequency band
  • definition of physical parameters (mass density, resistivity) by frequency band

• Sound sources properties:

  • integrated 'reference' spectrum database (can not be modified by users): white noise, road traffic spectrum…
  • integrated 'users' spectrum database (can be modified by users)
  • spectrum definition by frequency band in dB or dBA with attenuation
  • sound source characteristics : spectrum, position, directivity, delay, activate/desactivate
  • sound source classification in groups and sub-groups
  • copy, translation and rotation of groups and sub-groups of sound sources

• Sound reception:

  • ponctual receivers:
    • localization, directivity, orientation to a point, orientation (with link) to a source, definition of background noise
    • receivers classification in groups and sub-groups
    • copy, translation and rotation of groups and sub-groups of receivers
  • surface receivers (sound mapping):
    • definition of a surface by selecting surfaces of the model
    • definition of cut planes

• Fitting zone:

  • definition of zones with fitting objects characterized by probabilistic parameters (mean free path, absorption, diffusion law)
    • from built-in volumes in the 3D model
    • from manually design in the model (parallelelepidic volume)
  • activation/desactivation of fitting zones

• Environmental data:

  • relative humidity, atmospheric pressure, temperature
  • automatic calculation of absorption coefficient (ISO 9613) or fixed value
  • meteorological parameters: log-lin sound speed velocity profiles

• Acoustical post-processing:

  • Standard room acoustics parameters (EN ISO 3382-1): Reverberation time s(RT15, RT30, RT 'user', EDT), Clarity (C50, C80, C 'user'), Definition (D50, D80, D 'user'), Early support ST, Centre time Ts, Strength G, Early Lateral Energy Fraction LF and LFC, Late Lateral Sound Level LG
  • Echogram and Schroeder integration curves
  • Intensity vectors
  • Sound map (surface receivers): stationary, time-varying, cumulated values
  • Iso-contour (surface receivers)
  • Ray-tracing and particle-tracing animation

• Other:

  • Built-in Delaunay tetrahedric meshing using TetGen code (fully parametrized)
  • OpenGL® support with several modes for viewing and camera
  • Graphical visualization and image exports
  • Dockable interface
  • Multi-monitors viewing

Interface description

• Basic description
• Menus
  • Menu 'File'
  • Menu 'Edition'
  • Menu 'Animation'
  • Menu 'Tools'
  • Menu 'View'
  • Menu 'Windows'
  • Menu 'Help'
• Tool bars
• 'Project' window
  • Principle, definitions and common functionalities
  • Tab 'Scene'
  • Tab 'Calculation'
  • Tab 'results'
• 'Properties' window
• 'Console' window

Thematics

• Scene configuration
• Calculation configuration
• Visualization of results

Tutorials

• Study of teaching room
• Study of a concert Hall
• Study of an industrial hall
• Scripting examples

Additional resources

Reference

• SPPS code
• TCR code

Extend I-Simpa

Personalize I-Simpa

• Change icons
• Add colormap
• Add/modify language files

I-Simpa format files

Create Toolboxes

Appendix

• Room acoustics parameters
• Warning and error messages
• ISO Standards

Privacy, property and trademarks

Web publications

All publications within the I-Simpa website are properties of the Ifsttar (French Institute of Science and Technology for Transport, Development and Networks), Cité Descartes – Boulevard Newton – F-77 Champs-sur-Marne (France).

Property

I-Simpa is property of the French institute of sciences and technology for transport, development and networks (Ifsttar).

Trademarks

Products and brand names are trademarks™ or registered® trademarks of their respective holders.