A new method of calculation of north-light sheds is presented. The sheds considered are of one span and consecutive shed units are connected-apart from the window posts-by a solid wall for a short length in the window plane near the two supports. It is shown that this connexion creates a kind of fixation of the sheds in the form of a restraining moment acting in the horizontal direction, causing a reduction of the maximum compressive stresses at the centre of the span at the top of the gutter beam to about one-third the value it would take if each unit were unconnected to other shed units on either side. Sheds connected in the manner mentioned can be built to cover much bigger spans. The extra quantity of concrete required for the attachment of consecutive sheds is negligible while economy in the longitudinal reinforcement can be achieved. Amin Ghali
Mr. Bowen, in opening the proceedings, recalled that National Productivity Year began in November. Of its aims, the one which many people regarded as of paramount importance was to explore possible means of, and draw attention to the need for, raising efficiency in all industries. Whether or not Britain joined the European Common Market, she must expect to face fierce international competition in all spheres of activity.
The behaviour at collapse of mild steel beams of rectangular section is examined for the case of transverse loading applied in the planes of both major and minor axes. The usual criteria for the plastic failure of a two-dimensional flexural structure are applied to these problems. The yield criterion will be found to involve the development of the full plastic moment about axes other than the principal axes and the mechanism condition requires the formation of two, three or four bar linkages, the kinematics of which have to be taken into account. Solutions determining the collapse loads are obtained and tests are described which enable a comparison of predicted and observed collapse loads to be made. H.B. Harrison
In Part 1 of this series1 a computer programme which determines the equilibrium geometry of a free suspension cable under a pattern of vertical loading was described. D. M. BROTTON and G. ARNOLD