3 - Finding the Mass

b - More Accurate Method

First

Find the values of natural frequency and damping for your model.

Hint ! Visit the Resistant Buildings pages to:

EITHER guess the values, by visiting the Model Gallery and choosing values from a model that looks similar to yours.

OR measure the values by doing the
Free Vibration Decay Experiment.

Then

Use the Accurate Earthquake Mass Calculator to find out the mass needed to be hung from each floor to represent the IDEERS Design Earthquake.

Note ! If you have found out about "Energy dissipation systems" on the IDEERS Resistant Buildings pages and included one in your model, you can probably use a much lower mass. Unfortunately,then we don't know enough about your design to help calculate the required mass.

page 3 of 4

    Earthquake Load Test
       - Finding the Mass
            - Accurate Method

from Bristol University