The Static and Dynamic Testing of Full Scale Steel Chimneys

The paper gives details of the distribution of moments and forces induced in the beams and columns of a large, rigid, multi-storey, steel-framed building, due solely to a vertical settlement of any column. The construction is described and a typical frame is chosen and analysed elastically. From this empirical approach a pattern appears to emerge, and it is hoped that this information will be of use to engineers engaged in thc design of such buildings on difficult sites where sizeable differential scttlements may have to be accepted. E. Litton and J.M. Buston

The paper describes a method for the dynamic analysis of complex frameworks assuming a distributed mass-stifiness criterion. When compared with the lumped mass-stiffness technique, the proposed method is more accurate for the detcrmination of the response and natural frequencies of such frameworks. Moreover, the lumped mass technique discusses only a limited number of vibration modes, depending on the number of lumped masses assumed by the idealized system. The proposed method, however, trcats the framework as an infinite degrees of freedom system and thus will discuss all its possible modes of vibration. The method is also compared with the 'Duncan receptance technique' showing its superiority especially when dealing with highly redundant complex frameworks. M.E. Mohsin and E.A. Sadek

The matrix methods of structural analysis are, by now, well known. However, once large structures, such as the present-day skyscrapers, that consist of a vast number of components, are dealt with, various difficulties arise. Some of these difficulties are due to the fundamental approach to structural problems, while others are due to the speed and storage facilities of contemporary computers. A third group of difficulties is due to the various techniques that may be used in the processes of analysis, iteration, etc. K.I. Majid and D. Anderson