Mechanics of Materials

Lesson 13

Centroid and Moment of Inertia

Learning outcomes

Statics Review:
  • Explain the concept of centroid as the center of cross-sectional area.
  • Memorize the equation for moment of inertia of a rectangular cross-section.
  • Compute y bar for a composite shape by using an additive method (solids)
  • Compute y bar for a composite shape by using a subtractive method (solids and voids).
  • Identify the location of the centroid by inspection for cross-sections with a line of symmetry.
  • Apply the parallel axis theorem to compute the centroidal moment of inertia using an additive method (solids).
  • Apply the parallel axis theorem to compute the centroidal moment of inertia using a subtractive methods (solids and voids).
This Course:
    1. Explain the relationship between the moment of inertia and the magnitude of beam stresses, strains, and deflections.
    2. Distinguish between strong-axis bending and weak-axis bending.
    3. Given a cross-section, determine which centroidal axis is the strong-axis and which is the weak-axis.

In-Class Notes

LE13 Centroid and Moment of Inertia.pdf

Homework

HW13 Centroid and Moment of Inertia.pdf

Resources