Stress Concentration Factors for Simple Tubular X Joints

In-plane bending

X image
$$ \beta = \frac{d}{D} $$
$$ \alpha = \frac{2L}{D} $$
$$ \gamma = \frac{D}{2T} $$
$$ \tau = \frac{t}{T} $$
Location Equation Short chord correction
Chord saddle $\gamma \tau \beta \left(1.56 - 1.34 \beta^4\right)\left(\sin\left(\theta\right)\right)^{1.6}$ F3
Brace saddle $\tau^{-0.54}\gamma^{-0.05}\left(0.99-0.47\beta+0.08\beta^4\right)\gamma \tau \beta \left(1.56 - 1.34 \beta^4\right)\left(\sin\left(\theta\right)\right)^{1.6}$ F3

Short chord correction factor $\left(\alpha \lt 12 \right)$

$F3 = 1 - 0.55\beta^{1.8}\gamma^{0.16}\exp\left(-0.49 \gamma^{-0.89} \alpha^{1.8}\right)$