Torsion Constant for Rectangle Cross-section

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

Torsion Constant for Rectangle Cross-section formula

 $$\large{ J = a\;b^3 \left[ \frac{1}{3} - 0.21 \; \frac{b}{a} \; \left(1- \frac{b^4}{12\;a^4} \right) \right] }$$

Where:

 Units English Metric $$\large{ J }$$  (Greek symbol alpha) = torsion constant $$\large{\frac{lbf-ft}{rad}}$$ $$\large{\frac{N-m}{rad}}$$ $$\large{ a }$$ = length of long edge of an rectangle $$\large{in}$$ $$\large{m}$$ $$\large{ b }$$ = length of short edge of an rectangle $$\large{in}$$ $$\large{m}$$