Dr Joseph Gibson CBE FREng

Died on aged 94

Sir William Rede Hawthorne CBE FREng FRS

Died on aged 98

Obituary for Sir William Rede Hawthorne CBE FREng FRS on www.telegraph.co.uk and The Guardian

Mr Harry Ronald Hewitt FREng

Died on aged 90

Sir Gordon Robert Higginson DL FREng

Died on aged 81

Obituary for Sir Gordon Robert Higginson DL FREng on www.yorkshirepost.co.uk

Emeritus Professor John Neville Hutchinson FREng

Died on aged 84

Dr Alfred James Kennedy CBE FREng

Died on aged 89

Mr Bernard Douglas Mills FREng

Died on aged 82

Dr Leslie Sydney Dennis Morley FREng FRS

Died on aged 87

View appreciations

Appreciation from Professor Alan Morris FREng FRAeS and Dr Peter Bartholomew FRAeS

Les Morley started his working life at Airspeed Portsmouth where he was an apprentice fitter from 1939-44 after which he entered the company's Stress Office. In 1946 he was an inaugural student at the College of Aeronautics at Cranfield and obtained a post-graduate Diploma in 1947; the College had the progressive policy of offering post-graduate places to talented individuals who did not have a first degree. This was followed by a year at the National Luchtvaartlaboratorium (Amsterdam) and a period at the Bristol Aerospace Co after which he joined Structures Department at the Royal Aircraft Establishment (RAE) in 1950 where he remained until retiring in 1984.

Immediately he immersed himself in high level research into structural behaviour. In response to the Comet disaster in 1954 much research in Structures Department focused on the behaviour of cylindrical shells; Les developed an improved theoretical basis for approximating the behaviour of thin-walled cylindrical shells that is in use today. His work extended to include skew plates leading him to produce a monograph entitled 'Skew Plates and Structures' in 1963.

As the Finite Element Method rose to prominence, Les realised that there are inherent difficulties in representing inextensional bending using shell finite elements. He then worked on developing a set of new finite elements able to handle complex shell behaviour both in the linear and non-linear regime. He also observed that it was possible to augment the finite element solution using singular solutions in order to calculate the stress intensity factor at a crack tip in a thin-walled metal structure and thereby compute crack propagation rates. Following his retirement from the RAE he worked at Brunel University under contract to the Ministry of Defence.

Les was elected a fellow of the Royal Academy of Engineering in 1982 and a fellow of the Royal Society in 1992. We and many other researchers had the benefit of working directly with him in our early careers. He always required rigour and the highest quality research from us. Nevertheless he was a kindly man and always helpful; the phrase 'a scholar and a gentleman' is an epitaph that fits him perfectly.

Dr Peter John Nevitt FREng

Died on aged 78