In order to validate the principal assumptions inherent to plastic design of frames and continuous beams, it is necessary to predict the available rotation capacity at positions in the structure where plastic hinges are likely to form at collapse. The required rotation capacity is a function of the geometry of the structure and the loading and may be quantified within certain broad parameters. In order to predict the rotation capacity available at critical points in the structure, it is necessary to satisfy limit states criteria on a consistent basis. This paper deals with a proposed method of predicting the available rotation capacity and classifying members rather than sections. The available rotation capacity is predicted on the basis
of two principal parameters and an interaction equation. The proposed prediction model is compared with experimental results.