5.7.2. Relative Displacement

Try these first

1. 1.

   What is the formula for relative displacement?

   Hint

   Think about how we define the movement of a mass relative to the ground.

2. 2.

   If a mass displaces 0.8m during an earthquake with a ground displacement of 0.4m, what is the relative displacement?

   Hint

   Use the formula for relative displacement.

3. 3.

   What is relative displacement?

   • The movement of a mass.
   • The difference between mass displacement and ground movement.
   • The total displacement of a structure.

   Hint

   Think about what 'relative' means.

4. 4.

   True or False: Increased damping always decreases relative displacement.

   • True
   • False

   Hint

   Connect damping with energy dissipation.

5. 5.

   A building oscillates with a natural period of 1.5 seconds during an earthquake. If the mass displaces 0.75m and the ground moves 0.5m during shaking, find the relative displacement and evaluate the significance of the results.

   Hint

   Use the subtraction mentioned for ur.

6. 6.

   Discuss how varying levels of damping in structures affect their response to earthquake motions. Provide examples of structures with high and low damping characteristics.

   Hint

   Consider examples of damping systems in real structures.