Model Building Sequence

Follow this sequence when building a model to define all necessary components correctly.

  1. Materials

    After building the first model, you may find that materials are typically retrieved from an earlier model rather than redefined each time. It is recommended that you keep a material library that contains records for commonly used materials. A material library is saved as an Altair SEAM file (*.sea) but only contains material records.

  2. Damping

    A damping library, similar to the material library, can be useful for subsequent models.

  3. Elements
    Defined after materials and damping because they require material and damping as part of their parameters. Used to define a substructure or acoustic region, elements store and dissipate vibratory energy and provide paths for vibration and acoustic power flow. A single element contains one or more SEA subsystems.
    • Acoustic

      An element type supporting acoustic modes, such as axial (one-dimensional), tangential (two-dimensional), or oblique (three dimensional) modes.

    • Structural

      An element supporting structural modes, such as bending, shear, or torsion.

    • Element Types
      The following basic element types are available from the drop-down menu in the element type field on the Element. The seven basic element types are:
      Beam
      A one-dimensional structural element with a constant cross-section supporting bending, torsional, longitudinal, and higher-order cross-sectional deformation modes. See Beam subsystems and Beam options.
      Pipe
      A closed cross-section structural element with bending, longitudinal, and shear modes. Pipe bending includes beam-like low frequency behavior, lobar cross-sectional deformation modes, and plate-like high frequency behavior.
      Plate
      A two-dimensional flat panel structural element supporting bending and in-plane deformation modes.
      Shell
      A two-dimensional curved structural element supporting radial, tangential, and longitudinal deformation modes.
      Ac_duct
      A one-dimensional acoustic element supporting acoustic modes.
      Ac_layer
      A two-dimensional acoustic element supporting acoustic modes.
      Ac_space
      A three-dimensional acoustic element supporting acoustic modes.
      Ac_Semi infinite
      A three-dimensional acoustic element supporting infinite propagation.
  4. Subsystem

    An SEA subsystem is a group of modes with similar characteristics such as resonant frequency, mode shape, damping, and coupling.

  5. Connections

    Connections between elements.

  6. SEA Excitations

    Applied to elements or connections, and defined last.