Discussion. Behaviour of Sheeted Portal Frame Sheds: Theory and Experiments.

Abstract

University of Manchester) said that he would like to refer to a method of performing the analysis which gave results relevant to any number of intermediate frames. This method was found to be permissible within certain limits.133. The basis of the method was to replace the discrete resistance to spreading of theintermediate frames byacontinuousresistanceuniformly distributed. The sheeting itself acted as a shear field, so that the problem reduced to a shear field contained within an elastic medium.134. It was convenient to consider axes O X , OY ( Fig. 25(a)) taken in a horizontal plane, with axis OX coincident with the line of the eaves in the unloaded position. A and B were then the eaves of the gable frames which did not deflect, being a distance apart of (n+ I)a where n was the number of intermediate frames and a was the frame spacing. The origin 0 was taken mid-way between A and B.135. Supposing that each frame were subjected to a spread load force P, this would be approximated by a uniformly distributed spread load of Pia per unit length. The frame resistance for an eaves displacement of y was y / k , so that per unit distance along OY, the frame resistance was y/ka. The shear resistance of a panel was ( Y , + I -ys>/cl where Y & +~, y , were the eaves displacements of the frames either side of the panel. But ys +ys = a. dy/dx, so that the shear force in a panel was 136. It was supposed that, under the action of the uniformly distributed spread force P/a per unit length, the eaves deflected into the position ACB ( Fig. 2S(a)).Considering the equilibrium of an elemental length of eaves DE (Fig. 25(b)) of length dx, the forces on the element were as shown. Resolving along OY,Also, Hence *Proc. Znstn civ. Engrs, 1964, 29 (Dec.) 743-78. 23 1 Downloaded by [] on [12/09/16].