SEA Subsystem

There are three approaches to building an SEA subsystem:
  1. Import CAD geometry.
  2. Import an FE model.
  3. Use geometric entities.

In SEAM, a dynamic system is separated into a series of structural and acoustic elements. In the SEA analysis procedure, these elements are separated even further into SEA subsystems. A certain number of subsystems, or mode groups, are needed to completely describe the response of an element. However, in some cases, the loading and/or boundary conditions on a particular element justify the omission of certain standard subsystems and the addition of more complex subsystems in the analysis.

An SEA subsystem can be created using each specific option. Once a subsystem is created, you can assign properties and materials, which are created and assigned.

There are eight types of basic elements. Each icon in the SEAM ribbons corresponds to a different element type. These elements are categorized as structural and acoustic elements.

Structural
  • Plate
  • Shell
  • Beam
  • Pipe
  • Frame


Figure 1. Structural Elements
Acoustic
  • Acoustic space (3D)
  • Acoustic layer (2D)
  • Acoustic duct (1D)
  • Acoustic SIF (3D)


Figure 2. Acoustic Elements

Create and Edit a Plate

A plate is a two-dimensional, flat panel structural element that supports bending and inplane deformation modes.

  1. From the Model ribbon > SEA Subsystems group, click the Structural icon, followed by the Plate tool.
    Figure 3.


  2. Create a plate:
    1. Left-click in the modeling window to select a point or node until you are able to create a plate.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 4.


      Figure 5.


      Figure 6.
    3. Specify the plate name in the name field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a plate.


      Figure 7.

      The required parameters to create the plate subsystem are updated.

  3. Right-click on Plate to edit the subsystem and update the parameters.


    Figure 8.


    Figure 9. Plate Entity Editor
    Name
    Specify a unique name.
    ID
    Specify a unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 10.

Create and Edit Space

Space is a three-dimensional, acoustic element supporting acoustic modes.

  1. From the Model ribbon > SEA Subsystems group, click the Acoustic icon, followed by Space tool.
    Figure 11.


  2. Create space.
    1. Click a Surface, Plate, or Shell subsystem. If all subsystems or surfaces make it a closed entity, then it creates a cavity.
    2. Once you select a proper closed entity, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 12.


      Figure 13.


      Figure 14.
    3. Specify the space name in the field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create space.


      Figure 15.

      The required parameters to create a space subsystem are updated.

  3. Right-click on space to edit the subsystem and update the parameters.


    Figure 16.


    Figure 17. Space Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Absorption 1
    Define or select the absorption entity and define the area about it.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 18.

Create and Edit a Semi Infinite Fluid (SIF)

An acoustic element represents the infinite propagation medium for an exterior radiation scenario/problem. It can be attached to multiple acoustic subsystems to transfer the energy. The acoustic connections automatically consider the propagating surface area for connections. This element automatically creates semi-infinite acoustic space and connects the exterior-most acoustic space that you select.

  1. From the Model ribbon > SEA Subsystems group, click the Acoustic tool, followed by SIF tool.
    Figure 19.


  2. Create SIF.
    1. From the Entity selector, click an Acoustic space subsystem, which needs to be connected to a SIF.
    2. Click Create.


      Figure 20.
  3. After clicking Create, a Semi-infinite Acoustic Space 3D element is created with connecting acoustic space subsystems, which were selected in the previous step using the acoustic connections.
  4. The exterior surface of the acoustic space is considered for the acoustic connection's area.
  5. Right-click SIF to edit the subsystem and update the parameters.


    Figure 21. SIF element represented, with its connections


    Figure 22.
    Name
    Specify a unique name.
    Unique ID
    Specify a unique ID.
    Config
    The element type.
    Acoustic Spaces
    Specify the acoustic space to connect. Update the entities to add or remove.

Create and Edit a Layer

A layer is a two-dimensional acoustic element that supports acoustic modes.

  1. From the Model ribbon > SEA Subsystems group, click the Acoustic icon, followed by the Layer tool.
    Figure 23.


  2. Create a layer.
    1. Left-click in the modeling window to select a point or node until you are able to create a layer.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 24.


      Figure 25.


      Figure 26.
    3. Specify the name in the field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a layer.


      Figure 27.

      The required parameters to create the layer subsystem are updated.

  3. Right-click on Layer to edit the subsystem and update the parameters.


    Figure 28.


    Figure 29. Layer Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Absorption 1
    Define or select the absorption entity and define the area about it.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 30.

Create and Edit a Duct

A duct is a one-dimensional acoustic element that supports acoustic modes.

  1. From the Model ribbon > SEA Subsystems group, click the Acoustic icon, followed by the Duct tool.
    Figure 31.


  2. Create a duct.
    1. Left-click in the modeling window to select a point or node until you are able to create a duct.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 32.


      Figure 33.


      Figure 34.
    3. Specify the duct name in the field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a duct.


      Figure 35.

      The required parameters to create the duct subsystem are updated.

  3. Right-click on a Duct to edit the subsystem and update the parameters.


    Figure 36.


    Figure 37. Duct Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Absorption 1
    Define or select the absorption entity and define the area about it.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 38.

Create and Edit a Shell

A shell is a two-dimensional flat panel structural element that supports bending and inplane deformation modes.

  1. From the Model ribbon > SEA Subsystems group, click the Structural icon, followed by the Shell tool.
    Figure 39.


  2. Create a shell.
    1. Left-click in the modeling window to select a point or node until you are able to create a shell.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 40.


      Figure 41.


      Figure 42.
    3. Specify the name in the dialog.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a shell.


      Figure 43.

      The required parameters to create the shell subsystem are updated.

  3. Right-click on Shell to edit the subsystem and then update the parameters


    Figure 44.


    Figure 45. Shell Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 46.

Create and Edit a Beam

A BEAM is a one-dimensional structural element with a constant cross-section that supports bending, torsional, longitudinal, and higher-order, cross-sectional deformation modes.

  1. From the Model ribbon > SEA Subsystems group, click the Structural icon, followed by the Beam tool.


    Figure 47.
  2. Create a beam.
    1. Left-click in the modeling window to select a point or node until you are able to create a beam.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 48.


      Figure 49.


      Figure 50.
    3. Specify the name in the field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a beam.


      Figure 51.

      The required parameters to create the beam subsystem are updated.

  3. Right-click on beam to edit the subsystem and update the parameters.


    Figure 52.


    Figure 53. Beam Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 54.

Create and Edit a Pipe

A pipe is a one-dimensional structural element with a constant cross-section that supports bending, torsional, longitudinal, and higher-order, cross-sectional deformation modes.

  1. From the Model ribbon > SEA Subsystems group, click the Structural icon, followed by the Pipe tool.
    Figure 55.


  2. Create a pipe.
    1. Left-click in the modeling window to select a point or node until you are able to create a pipe.
    2. After selecting more than two points, a guidebar is displayed that you can use to assign properties, , and damping, .


      Figure 56.


      Figure 57.


      Figure 58.
    3. Specify the name in the field.
    4. Click and assign properties and damping, respectively.
    5. Click Create to create a pipe.


      Figure 59.

      The required parameters to create the pipe subsystem are updated.

  3. Right-click on pipe to edit the subsystem and update the parameters.


    Figure 60.


    Figure 61. Pipe Entity Editor
    Name
    Specify unique name.
    ID
    Specify unique ID.
    Config
    Specify the element type.
    Property
    Specify the property parameter based on the element type.
    Damping
    Specify damping to the subsystem.
    Geometry
    Based on the element type, update geometry parameters.
    Subsystem Options
    For experienced users, expand the Subsystem Options to change the default choices for the SEA Subsystems for all element types. For certain structural element types, use these options to adjust the default bending stiffness or conductance of the element and add non-structural mass, component mass, or fluid loading to the element when the options have been changed.
    Damping
    Assign a damping model to the element. From the Damping field drop-down menu, select a damping model. This list contains all predefined models which apply to the current element type. Click to display advanced damping options that you can use to define additional damping models.
    Properties
    Assign a property model to the element. From the Property field drop-down menu, select a property model. The element materials and cross-sectional parameters defined in the selected Property record are displayed. Property records can be used to simplify the model definition in cases where many elements have the same properties. Click to display advanced property options that you can use to define additional property models.


    Figure 62.