SS-T: 4160 Response Spectrum Analysis

Purpose
SimSolid performs meshless structural analysis that works on full featured parts and assemblies, is tolerant of geometric imperfections, and runs in seconds to minutes. In this tutorial, you will do the following:
  • Create response spectrum analysis for a building structure with base excitation load.
Model Description
The following model file is needed for this tutorial:
  • Building_structure.ssp
  • Spectrum_Function.csv
Figure 1.


The file has the following specifications:
  • Material is set to Steel for all parts.
  • Regular connections with 1mm gap and penetration tolerance.

Open Project

  1. On the main window toolbar, click Open Project .
  2. In the Open project file dialog, select Building_structure.ssp.
  3. Click OK.

Create Modal Analysis

  1. On the main window toolbar, click the (Modal analysis) icon.
  2. In the Number of modes window, specify the number of modes as 20.
  3. Click OK.
    The new modal analysis appears in the Project Tree.

Create Immovable Support

  1. On the Analysis Workbench, click Immovable support.
  2. In the dialog, verify the Faces radio button is selected.
  3. In the modeling window, select the faces highlighted in orange from the figure below.
    Figure 2.


  4. Click OK.
    The new constraint, Immovable 1, appears in the Project Tree. A visual representation of the constraint is shown on the model.

Edit Solution Settings

  1. In the Analysis branch of the Project Tree, double-click on Solution settings.
  2. In the Solution settings dialog, for Adaptation select Global+Local in the drop-down menu.
  3. Click OK.

Run Analysis

  1. On the Project Tree, open the Analysis Workbench.
  2. Click Solve.

Review Results

  1. In the Project Tree, select the Model 1 subcase.
  2. On the Analysis Workbench toolbar, click Results plot.
  3. Select Displacement Magnitude.
    The Legend window opens and displays the contour plot. The Frequency (Hz) window opens and displays the modes.
    Figure 3.


Create Response Spectrum Analysis

  1. On the main window toolbar, select (Dynamics) > Spectrum.
    The Dynamic response Spectrum setup dialog opens.
  2. Link to the available Modal analysis result.
  3. Set the Modal combination type to ABS.
  4. Click OK.

Create Frequency Function

Frequency functions are referenced by dynamic spectrum loads.

  1. On the Project Tree, click on the Assembly workbench.
  2. On the Assembly workbench toolbar, click Frequency function.
  3. In the dialog, click Import CSV.
  4. In the File explorer, browse to the Spectrum_Function.csv file and click Open.
    The function is plotted in the XY graph in the dialog.
    Figure 4.


Define Loads

  1. On the Assembly workbench toolbar, click Base excitation.
  2. In the dialog, set Excitation type to Acceleration.
  3. Set the Units to [mm/sec^2].
  4. For Amplitude, enter 9800.
  5. For Direction, enter 1 for X and 0 for Y and Z.
  6. Click OK.

Run Analysis

  1. On the Project Tree, open the Analysis Workbench.
  2. Click Solve.

Review Results

  1. In the Project Tree, select the Spectrum dynamics 1 subcase.
  2. On the Analysis Workbench toolbar, select (Results plot) > Displacement Magnitude Relative.
    Figure 5.