An overview of the plastic-hinge analysis of 3D steel frames

Asia Pacific Journal on Computational Engineering

Table 8 Determination of the web plan vector for a current configuration

⁽ⁱ⁻¹⁾ I, ⁽ⁱ⁻¹⁾ J, ⁽ⁱ⁾ I and ⁽ⁱ⁾ J are the coordinates of the nodes at the last (i − 1)th and the current (i)th configurations, respectively
⁽ⁱ⁻¹⁾yk is web plan vector of the element at the last configuration, perpendicular to the member axis
φ_k is the rotation of the element about its axis (Table 6)
\({}^{(i - 1)}\bar{y}_{k}\) is the position of ^(i-1)y_k after performing the rotation φ_k
\({}^{(i)}\bar{y}_{k}\) is a web plan vector of the member at the current configuration, parallel to \({}^{(i - 1)}\bar{y}_{k}\)
\({}^{(i)}y_{k}\) is the web plan vector of the current configuration that is \({}^{(i)}\bar{y}_{k}\) after normalizing (still in the web plan but perpendicular to the member axial axis)