Abstract

The momentum transfer by a planar wave impinging upon a rigid, freestanding plate in water, a largely incompressible medium, is well understood [1]. Kambouchev et al. [2] extended the results of Taylor [1] to include the nonlinear effects of compressibility whilst Hutchinson [3] has addressed the issues of energy and momentum transfer to a rigid, freestanding plate. In this presentation, key conclusions from the aforementioned studies will be critically re-examined in the context of a flexible, `fully-clamped’ elasto-plastic beam both under water and in air. The dynamic response of the elasto-plastic beam will be modelled as an equivalent single-degree-of-freedom (SDOF) system. A numerical method based on a Lagrangian formulation of the Euler equations of compressible flow and conventional shock-capturing techniques, similar to that employed in [2, 3], are employed to solve numerically the interaction between the blast wave and beam. Particular emphasis will be placed on elucidating the energy and momentum transferred to the structure compared to its rigid, freestanding counterpart, and on whether enhancement in the beneficial effects of FSI remains, with or without fluid compressibility, and to what extent.

References

[1] G. I. Taylor, in: The pressure and impulse of submarine explosion waves on plates, edited by G.K. Batchelor, Vol.3 of The Scientific Papers of Sir Geoffrey Ingram Taylor, Cambridge University Press, Cambridge (1963) 287–303. [2] N. Kambouchev, L. Noels, R. Radovitzky, Nonlinear compressibility effects in fluid-structure interaction and their implications on the air-blast loading of structures, J. Appl. Phys. 100 (2006) 063519. [3] J. W. Hutchinson, Energy and momentum transfer in air shocks, ASME J . Appl. Mech. 76 (5) (2009) 051307.