ABSTRACT
The objective of this paper is how to determine the rotation requirements and rotation capacities in plastic hinges of structures made of hollow sections. These values are needed to check whether the rotation capacity of the sections is sufficient for plastic design. In several design codes (e.g. Eurocode 3) such checks are bypassed by a classification of the hollow sections according to their b/t-ratios in the compression zone. These b/t-ratios which limit the applicability of plastic design correspond to rotation requirements that by nature of such lump rules are extremely conservative.
The paper describes in its first part the determination of a general rotation requirement of rectangular, square and circular hollow section beams for the example of a continuous beam with three spans using a nonlinear analysis program. Furthermore in the second part an unusual test arrangement for the experimental determination of the rotation capacity of hollow section beams is described. A finite element model is presented which simulates the experimental tests.
