Equivalent Member Length

Equivalent member length

l_{ef} = \frac{L}{a_{1} \cdot (1 - a_{2} \cdot \frac{a_{z}}{L} \cdot \sqrt{\frac{E_{0.05} \cdot I_{z}}{G_{0.05} \cdot I_{T}}})} \cdot \frac{1}{α \cdot β}

l_ef	Equivalent member length
L	Beam length, spacing between lateral supports
a₁,a₂	Lateral buckling factors
a_z	Distance of the load application from the shear center
E_0.05	5 % quantile of the modulus of elasticity
G_0.05	5 % quantile of shear modulus
I_z	Second moment of the area about the weak axis
I_T	Torsional constant
α, β	Factors for considering a member foundation

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