Calculadora de Momento de ÁreaFórmula

## Second Moment of Area for a Rectangle

The second moment of area (often called moment of inertia of the cross-section) governs how a beam resists bending.

### Formula

**Ixx = b h^3 / 12**

**Iyy = h b^3 / 12**

where b is the width and h is the height of the rectangle. The axis with the larger I value provides greater bending resistance. That is why beams are oriented with the taller dimension vertical.

Ejemplo Resuelto

A rectangular timber section 100 mm wide and 200 mm tall.

  1. Ixx = 100 x 200^3 / 12 = 100 x 8,000,000 / 12 = 66,666,667 mm^4
  2. Iyy = 200 x 100^3 / 12 = 200 x 1,000,000 / 12 = 16,666,667 mm^4
  3. Ixx in cm^4 = 66,666,667 / 10,000 = 6,666.67 cm^4