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XXXV. Strength of the Reinforced Thin-plate Beam, held at 

 its ends, and subject to a uniformly distributed Load — 

 Special Case. By B. 0. Laws', D.Sc. M.LC.E* 



IN two previous communications t the author gave 

 solutions of the thin-plate beam in which the latter 

 was fixed at its ends and subject to a uniformly distributed 

 load. 



It was shown how the stress in the material might be 

 determined when both the lateral loading and the direct 

 tension induced in the material were taken into consideration 

 in' obtaining the bending moment. 



In the present paper an extension of the problem is 

 considered wherein the thin plate is partially stiffened in 

 some way so that the Inertia value of the beam section 

 is not constant from end to end of the beam. 



The problem arises in practice where unsupported areas 

 of plating subject to hydrostatic loads become so large that 

 either the deflexion or the stress in the material or both 

 would reach a value exceeding the usual working limits 

 of safety, and it becomes necessary either to subdivide the 

 area by introducing intermediate rigid boundaries, or to 

 stiffen the plating at intervals so as to bring about such a 

 redistribution of load as will bring- the stress in the material 

 within the usual safe limits. 



It is true generally that the stress values, induced in a free 

 area of plate fixed along its edges, differ from those obtained 

 by considering a strip cut from the plate and subject to the 

 same unit load ; but often elongated rectangular areas of 

 plate are met with in which the maximum stress in the 

 material is not widely different from that obtained by taking 

 a strip of span equal to that of the shorter side of the 

 rectangle isolated and treated in the manner set out below, 

 and in the case of rectangle areas where the surface dimen- 

 sion ratio of the plate is not great the principles embodied 

 herein may, with good judgment, be utilized in the approxi- 

 mate determination of stress values. 



Apart from the particular problem under consideration, 



* Communicated bj r the Author. 



t Phil. Mag. vol. xxxi. April 1910, and vol. xxxii. July 1916. 



Phil. Mag. S. 6. Vol. 42." No. 248. Aug. 1 921. U 



