13.2. Stiffness Matrices

Try these first

1. 1.

   What is a stiffness matrix?

   Hint

   Think about how we relate forces and movements.

2. 2.

   What does E represent in the stiffness matrix equations?

   Hint

   Recall our discussions on material properties.

3. 3.

   What is the main purpose of the stiffness matrix?

   • To find displacements
   • To define shape
   • To relate forces and displacements

   Hint

   Think about the role of the stiffness matrix in equations.

4. 4.

   True or False: A beam element only handles axial loads.

   • True
   • False

   Hint

   Recall the definition of beam elements.

5. 5.

   A truss is subjected to an axial load of 5000 N. If the area is 0.002 m², and Young's modulus is 200 GPa, calculate its axial deformation.

   Hint

   Recall δ=PL/AE, and think about how you can rearrange it.

6. 6.

   If a beam of length 4 m has a moment of inertia of 0.0002 m⁴ and is subjected to a bending moment of 1000 N·m, find the beam’s deflection.

   Hint

   Look for how E affects deflection in bending.