摘要：In collapse analysis of plane framed structures there are many methods allowing the collapse mechanism to be determined but the position of the last plastic hinge always remains unknown, although its location is essential for the analysis of deformation. The ma- ximum displacement theorem could lead to an incorrect result when some plastic hinges are subsequently unloaded. The aim is to formulate an original method, making it easier to identify the final hinge and consequently providing a more thorough understanding of the deformation. The basic idea arises from a simple consideration: giving a framed structure any method of limit analysis allows the collapse mechanism and the moment distribution to be determined. However the last plastic hinge remains unknown. If one as- sumes that X is said hinge, then the sign of any plastic moment must agree with the sign of the corresponding plastic hinge rotation. Otherwise the moment is impossible and hence the analysis of deformation must highlight some discrepancy. Such discrepancy can only be between the sign of a plastic moment and the sign of the corresponding rotation for at least one plastic hinge involved in the collapse mechanism. The proposed original method is based on the study of deformation aimed to determine the reference state in which the sign accordance between plastic moments and corresponding hinge rotations occur.
