Comparison between Webshaker and SDOF Model using Earthquake-like Records Input

About this Experiment:
This experiment compares data from the live Webshaker experiment to the result of the Single Degree of Freedom (SDOF) equation computer program.

The default natural frequency in the SDOF program is 4 Hz and its damping ratio is 0.025. After the initial Webshaker experiment, users can adjust the natural frequency and damping ratio supplied to the SDOF program so as to achieve a better match with the Webshaker experiment.

The experiment uses earthquake-like records as base motion to the test structure during the experiment and hence simulate a real earthquake. This experiment allows users to see how a structure would respond to real earthquakes. The input motion delivered to the test structure are scaled and shortened versions of the earthquake records. The acceleration data in earthquake-like record is converted to a voltage signal which is sent to the shake-table delivering the base motion to the test-structure.

Please note that the result is only a rough experiment of how the test structure would respond to a real earthquake and cannot be used as an accurate prediction model.

Choose one of the earthquake-like records listed in the pull down menu below as base excitation for your Webshaker experiment and then click "Select" button.

Input for SDOF Program:

Natural frequency (Hz) (fn > 0)   *
Damping ratio (0 ≤ ζ1 ≤ 1)   * *

Input for Webshaker:

  • You can view time-domain plots of the Input Motion files here
  • You can view frequency-domain plots of the Input Motion files here