5.12.2. Modal Stiffness

Try these first

1. 1.

   What is modal stiffness?

   Hint

   Think about how stiffness relates to vibration.

2. 2.

   How is modal stiffness calculated?

   Hint

   Consider the components of the formula.

3. 3.

   What does modal stiffness represent in structural dynamics?

   • Stiffness of a structure
   • Stiffness for a specific mode
   • Mass of a structure

   Hint

   Focus on how stiffness applies to vibration.

4. 4.

   True or False: Modal mass is not a factor in determining modal stiffness.

   • True
   • False

   Hint

   Recall the formula k¿ = m¿ω².

5. 5.

   A structure has a modal mass of 500 kg and its fundamental circular frequency is 4 rad/s. Calculate its modal stiffness and explain what this value implies for its seismic behavior.

   Hint

   Use k¿ = m¿ω² for the calculation.

6. 6.

   Discuss the role of modal stiffness in the design considerations for earthquake-resistant structures, providing examples of how it affects material selection and structural layout.

   Hint

   Think of material properties and structural forms.