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Biaxial Bending AISC Chapter H. Bending about both Major and Minor axis of section. Biaxial Bending - Shear Center. Shear Center: That point through which loads must act if there is to be no twisting or torsion. Biaxial Bending - Shear Center. Shear Center:
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Biaxial BendingAISC Chapter H Bending about both Major and Minor axis of section
Biaxial Bending - Shear Center Shear Center: That point through which loads must act if there is to be no twisting or torsion
Biaxial Bending - Shear Center Shear Center: That point through which loads must act if there is to be no twisting or torsion
LRFD - Loads Through Shear Center Bending about y-only Bending about x-only Interaction Formula Allows the designer to allocate to one direction what has not been “used up” in the other direction
ASD - Loads Through Shear Center Bending about y-only Bending about x-only Interaction Formula Allows the designer to allocate to one direction what has not been “used up” in the other direction
Example W21x68 A992 12 ft MDx= 48 ft-kips MDy= 6 ft-kips MLx= 144 ft-kips MLy= 18 ft-kips All moments uniform over length of beam
A B P1 C D P2 E F Members Under Combined Forces Most beams and columns are subjected to some degree of both bending and axial load e.g. Statically Indeterminate Structures
Interaction Formulas for Combined Forces e.g. LRFD If more than one resistance is involved consider interaction
Basis for Interaction Formulas Tension/Compression & Single Axis Bending Tension/Compression & Biaxial Bending Quite conservative when compared to actual ultimate strengths especially for wide flange shapes with bending about minor axis
AISC Interaction Formula – CHAPTER H AISC Curve r = required strength c = available strength
A B P1 C D P2 E F Members Under Combined Forces Most beams and columns are subjected to some degree of both bending and axial load e.g. Statically Indeterminate Structures What is the effective length factor?