NUMERICAL SIMULATION OF THE COMPLETE INTERACTION BETWEEN AN UNSTEADY DYNAMIC SHOCK OR HIGH-FREQUENCY LOAD AND AN ELASTIC CIRCULAR CYLINDRICAL SHELL CONTACTING WITH FLUID

摘要

The complete three-dimensional interaction between a spherical shock wave and a completely sub-rnmerged ruid-flled circular cylindrical structure is studied. The combined numerical-analytical solvingrnprocedure is established for essentially coupled equations of ruid and a shell: an exact analytical solutionrnin the form of double Fourier series with time-depending coe?cients is obtained for the radiation andrndiu000braction pressure, and the stress-strain state analysis is approached analytically frst to reduce therndimensionality of the problem which then is treated numerically. Some important features of the inter-rnaction process have been found. In particular, along with the fact that the interior ruid dramaticallyrnau000bects the stress-strain state of a shell, it is shown that the absolute maximum of stresses is causedrnneither by direct action of an incident wave nor by elastic waves in a shell but by the pressure wave inrnthe interior ruid. Another important result is that these maximum stresses are attended at large times,rnthat makes use of the early-time asymptotics leading to essentially incorrect results.