John Douglas Eshelby FRS (21 December 1916 – 10 December 1981) was a scientist in micromechanics. His work has shaped the fields of defect mechanics and micromechanics of inhomogeneous solids for fifty years and provided the basis for the quantitative analysis of the controlling mechanisms of plastic deformation and fracture.
Eshelby was born at Puddington, Cheshire, the son of Captain Alan John Eshelby and his wife Phoebe Mason Hutchinson. He was educated at St Cyprian's School, Eastbourne and was due to go to Charterhouse School but developed rheumatic fever and received his secondary education privately at home. At about this time the family moved to Manor House at Farrington Gurney, Somerset where his tutors were the village schoolmaster and a local clergyman. He relied extensively on self-instruction and obtained a place in the Physics Department of Bristol University and was awarded a first class honours in physics in 1937. He then worked in a research laboratory under H W B Skinner and W Sucksmith on magnetism and the soft X-ray spectra of solids.
In World War II Eshelby began working for the Admiralty on the degaussing of ships, but on 4 May 1940 he joined the Technical Branch of the Royal Air Force. His work from February 1941 to June 1942 was for the Coastal Command Development Unit conducting performance trials of ASV and other operational devices in all types of aircraft. He was then involved in radar work, from August 1942 to February 1943 with 76 signals wing and from February 1943 to September 1944 at the radar establishment at Malvern. He was then transferred to disarmament work and then to the Air Historical branch in September 1945. He left the RAF as a squadron leader on 4 October 1946.
After the war Eshelby returned to Bristol University to study for a PhD and taught himself the theory of elasticity for his thesis on "Stationary and moving dislocations". After holding several early research posts he worked in the Cavendish Laboratory at Cambridge University and was elected a Fellow of Churchill College. He was then appointed Reader in the Faculty of Materials (Theory of Materials) at the University of Sheffield where he became Professor in 1971. He was elected a Fellow of the Royal Society in March, 1974. He was awarded the Timoshenko Medal in 1977. He died in 1981 and the Eshelby Memorial Bursary was founded in his memory.