Define the Input Spectrum

For more information, visit the Response Spectrums help topic.

  1. Right-click the Analysis Type heading in the browser and select Edit Analysis Parameters.
  2. Click Spectrum Data on the Analysis Parameters dialog box. The Response Spectrum Analysis Input dialog box displays. 
    1. Ensure that 1 is entered in the Use modal results from Design Scenario field. The program will use the results from the natural frequency (modal) analysis previously performed in design scenario 1.
    2. Activate the Generate Response Spectrum check box. A spectrum will be generated based on user-specified frequency and damping ratio values.
    3. Type 1 in the X Dir field.
      • Type 1 in the Y Dir field.
      • Type 1 in the Z Dir field. The spectrum will be applied in all three global directions.
    4.  Type 15 in the Oscillating Frequency (Hz) field.
      • Type 0.05 in the Damping Ratio (0.01 = 1%) field.
      • Type 1 in the Scale Factor field. The table of Period and Displacement values will automatically be populated and the spectrum graph will look like the image below.  Define the Input Spectrum
    5. Click OK to accept the input spectrum.
  3. Click OK to accept the analysis parameters.  
Parent topic: Truss Tower Response Spectrum Analysis