In the second part of this series on plastic collapse analysis, we explore how what we learned in part one can be applied the frames. Plastic analysis methods are particularly useful in the analysis of indeterminate steel portal frames as it allows us to efficiently achieve relatively large spans by allowing for the formation of plastic hinges and moment redistribution within the frame. By the end of this tutorial, you will be confident applying plastic analysis methods to very common single and double-bay frame structures.
Often in structural analysis, linear-elastic analysis is used, predicting failure when structural members reach their yield stress. This method, while effective, ignores the plasticity that some structural materials experience beyond their yield limit. This can lead to an underestimate of the structures safe working capacity. In part one of this tutorial series on plastic analysis, we explore the analytical methods used to evaluate the ultimate capacity of a structure, the so-called plastic limit or plastic collapse limit.