Lecture 28 Transfer Formula Example Problem

Lecture 28
Example Problem

Transfer Formula

Given:
the glued asymmetric built-up cross-section below.
Determine:
the moment of inertia of the composite area about the x axis.

Example problem

Solution:
The transfer formula was invented for cases such as this where a composite shape requires a single moment of inertia and the individual parts do not share their centroidal axis.

I_xx = sum (I_c + Ad²)

In this case:
I_xx = I_A +A_Ad² + I_B +A_Bd²
I_xx = 1/12(6in)(2in)³ + (12in²)(2in)² + 1/12(2in)(6in)³ + 12in²(2in)²
I_xx = 4 in⁴ + 48 in⁴+ 36 in⁴ + 48 in⁴

I_xx = 134 in⁴

Lecture 28 Example Problem

Lecture 28
Example Problem