12.7. Response to Earthquake Ground Motion

Try these first

1. 1.

   What does a two degree of freedom system represent?

   Hint

   Think about how many places forces can act independently.

2. 2.

   What is ground acceleration?

   Hint

   Consider how quick the ground is moving during an earthquake.

3. 3.

   What is the equation governing response to earthquake ground motion in a 2-DOF system?

   Hint

   Remember the components that represent mass, force, and response.

4. 4.

   True or False: The modal participation factor indicates that each mode contributes to the system's overall response.

   • True
   • False

   Hint

   Think about how each oscillation mode influences the total behavior.

5. 5.

   Given a 2-DOF system with masses and coefficients identified, derive the equations of motion and compute the modal participation factors.

   Hint

   Start by establishing your mass and stiffness matrices.

6. 6.

   If an earthquake causes a specific ground motion, calculate the total displacement response of a 2-DOF structure using modal superposition.

   Hint

   Think about how the contributions of different modes combine.