GB448300A - Apparatus for the determination of the nature, magnitude and/or variation in stress under varying conditions of load and/or pressure in the members of braced structures,suspension bridges and the like - Google Patents

Abstract

448,300. Educational appliances. CANTRELL, W. C., 126, Pepys Road, Wimbledon, London. June 4, 1935, No. 16154. [Class 146 (ii)] [See also Group XIX] Apparatus for demonstrating the nature and magnitude in stress under varying conditions of load in the members of braced structures comprises a rigid framework A in which a pinjointed model M of the structure is supported and loaded, the deflection of the model being marked and the load removed ; whereupon the member under investigation is next removed and replaced by applied regulable tensile forces which are adjusted to produce the same deflection when the load is reapplied. The framework A is built up of angle steels and stands vertically on shoes D. The model M is supported on brackets H adjustable in the slotted framework and secured by wedges I. Wires N on each side of the girder M give lateral stability and a board J attached to the framework is provided with clamps L which may be screwed up to engage the lower member of the girder in its deflected position to mark the latter. The loading being removed, the member under investigation is removed and forces applied at the pins by spring balances O and turnbuckles Q. The weight of the tensioning devices may be sustained by means such as S. The load is now replaced and the tensioning devices adjusted to give the same deflection as before. A three-hinged elbow attachment T may be fitted to accommodate the tensioning devices when used close to the frame.