Addison will be remembered by the terminal ballistics community for the Modified Bernoulli penetration model that accounted for the effects of material strength and presented in his two seminal papers of 1967 and 1969.
Addison was born in South Africa and went to Cambridge University where he graduated with honours in mathematics in 1955 and in aeronautical engineering in 1956. He spent his career at the Royal Armament Research and Development Establishment (RARDE), ranging from plasma physics and hypersonics to impact phenomena. He had a keen interest in engineering mechanics and developed analytical models for ricochet (1979), the penetration of tapered projectiles, and a later penetration model, referred to as the Solenoid Flow Field model (1986), which incorporated the various phases of penetration from transient to after-flow. His observations from impact experiments at RARDE in the 1970s led to a simple but effective empirical penetration model using L/D effects, critical penetration velocity and the linear section of the penetration depth vs. velocity trend. During the interest in segmented penetrators in the 1980's he developed an analytical model for the ideal spacing of segments, so they were sufficiently spaced to avoid clashing but close enough together to maximise the after-flow in the crater wall.
With E.W. Billington, he co-authored the textbook “The Physics of Deformation and Flow” (McGraw-Hill, 1981).