Tangent Stiffness Method for Biaxial Bending

Abstract
A method for computing generalized stress-strain relationships (moment-thrust-curvature relationships) for metal column sections in biaxial bending is described. The analytical formulation of the force-deformation equations in terms of the rate of change leads to a linear relationship between these quantities. Solutions are obtained by the tangent stiffness method and a digital computer. The method is found to be extremely powerful and efficient for computer solution.