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In the above equation , ki is the axis rotation of the element at the i end and is calculated from Equation (15A.1) . The value of ki is obtained by subtracting Δ / l c from the value obtained by dividing the translation between the element nodes by the element net span, and the rotation value of the node i . In this way , the value of θ ki is obtained with the values obtained as a result of the linear calculation.
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The θ yi value given in Equation (15A.2) is the yield rotation for frame elements and is calculated from Equation (15A.3) . In these equations, M yi and M yj are the effective yield moments at the ends i and j, respectively, and are calculated by the moment-curvature relationship derived from the section material model and the reinforcement layout. EI is the flexural stiffness of the unbroken section and is calculated from the section geometry.
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