A general criterion is described for assessing the inelastic rotation capacity of structural members and their connections. The results of 44 tests on the inelastic behaviour of steel I-sections under moment gradient are analysed by considering the relative influence on available rotation capacity of parameters normally associated with local and lateral buckling, as well as other effects described in earlier research. Two modes of failure are identified: lateral buckling dominant and inducing local flange buckling at higher lateral slenderness ratios and local flange buckling dominant and inducing lateral and local web buckling at lower lateral slenderness ratios. The onset of strain-weakening behaviour is assessed for both modes of failure of steel I-sections in plain steel and composite structures. It is concluded that there is no clear justification for a difference in the local buckling provisions for steel and composite beams. Professor A.R. Kemp and N.W. Dekker
This paper is limited in its scope to the five large members of the European Community - the UK, France, Spain, Germany, and Italy - and is based on the work carried out for CIRIA in preparing its reports on the construction industries of these countries. D. Ferry
Dr. P. J. E. Sullivan (F) I was interested to read the above paper and would like to comment on some aspects of the testing and the results.
The buckling of the support region of steel beams in continuous composite bridge construction is studied using an ultimate strength finite element analysis, the particular form of failure addressed being distortional lateral buckling of the beam lower flange and web. Results for a series of both practical and extreme girders are used to illustrate the inappropriate nature of the present BS 5400: Parts 3 and 5 design approach. A relatively small modification to this is suggested, which leads to very good predictions of all the numerical results. This revised design approach may be presented in chart form to show that, over most of the practical range of girder proportions, lateral buckling will not occur at moments below the full cross-sectional moment capacity. G. Weston,Professor D.A. Netheroct and Professor M.A. Crisfield
On many occasions, including when Chairman of the East Midlands Branch, I have taken part in several discussions and much correspondence on how to promote the profession and its members, and I would like to add to the ‘Viewpoint’ (4 December 1990) of Mr M. I. Murray, J.A. Baird