[2][3][4] He was the first to apply Griffith's energy release rate criterion to the analysis of rubber's strength and fatigue behavior.
His research director was Dr Ronald S. Rivlin, who suggested that he study the strength of rubber.
He developed the theories of strength and crack growth in rubber, starting from the work of Alan Arnold Griffith.
[5] He demonstrated that Griffith's strain energy release rate provided a useful way to characterize the conditions at a crack tip, a problem that previously had been thought intractable due to the finite straining and nonlinearly elastic stress-strain behavior of rubber.
[7] His employers MRPRA, received the Prince Philip award in 1990 for his pioneering work on earthquake bearings.