J. F. Baker
Professor John Fleetwood Baker (19 March 1901 – 9 September 1985) M.A., Sc.D D.Sc., Assoc.M Inst C E. (Telford Medal. Telford Premium. Howard Quinquennial Prize), M.I. Struct.E. Professor of Civil Engineering, University of Bristol, was a British scientist and structural engineer.
Plastic methods of design developed by J. F. Baker and his colleagues during the second world war exploit fully the continuity in a structure where the formation of a plastic hinge can result in the disposition of moment, and thereby utilise more fully the strength of the construction.[1]
The following information is condensed from the Wikipedia entry.
Born in Liscard, Cheshire. After graduation, Baker worked with the Air Ministry on structural problems of airships. At 28 he contracted tuberculosis. Upon recovering, he became a technical officer with the Structural Steel Research Committee, which was investigating why measured stresses in structural steel bore little resemblance to theoretical ones. During his time in this post, he developed the plastic theory of design, a revolutionary method of design of steel structures which gives a lower bound on the collapse load. Until then, design of steel structures was based on elastic theory of design. In 1932 he was awarded the Telford Gold Medal of the Institution of Civil Engineers for the work.
In 1933 Baker became Professor of Engineering at Bristol University, after which he was scientific adviser to the Design and Development Section of the Ministry of Home Security from 1939 to 1943. In this time he created the Morrison indoor shelter, using his plastic theory of structural analysis. Baker was appointed an OBE in the 1941 Birthday Honours.
The Wikipedia entry provides a summary of the basis of the design of the Morrison shelter:-
'It was impractical to produce a design for mass production that could withstand a direct hit, and so it was a matter of selecting a suitable design target that would save lives in many cases of blast damage to bombed houses. Examination of bombed buildings indicated that in many instances, one end wall of a house was sucked or blown out by a nearby blast, and the floor of the first storey pivoted about its other end (supported by a largely intact wall) and killed the inhabitants. The Morrison shelter was therefore designed to be able to withstand the upper floor falling, of a typical two-storey-house undergoing a partial collapse. The shelter was designed to absorb this energy by plastic deformation, since this can absorb two or three orders of magnitude more energy than elastic deformation. Its design enabled the family to sleep under the shelter at night or during raids, and to use it as a dining table in the daytime, making it a practical item in the house.'