METHOD OF SIMULTANEOUS ANALYSIS OF WAVES PROPAGATING IN MULTILAYERED MEDIA BY BOUNDARY-ELEMENT METHOD

In this paper, a method of simultaneous analysis of waves propagating through multilayered media consisting of gas and solid fields using th e boundary element method is proposed. Usually the waves propagating i n gas fields are analyzed using the Helmholz wave equation, where the unknown functions of sound pressures are taken to be scalars. Then, th e sound pressures obtained as the result of the analysis of the gas fi eld are imposed on to the solid fields as external forces and the wave s propagating in the solid are been analyzed, taking the unknown funct ions of particle velocities to be vectors. That is, the waves propagat ing in gas and solid fields are analyzed separately. Naturally, it is considered to be more effective to analyze the waves propagating in ga s and solid fields simultaneously than to analyze them separately. In this work, a method of simultaneous analysis of Raves propagating thro ugh multilayered media using the boundary element method has been deve loped, using the same equation of motion for gas and solid and conside ring the same unknown functions of particle velocities as vectors. Als o several conditions under which the solutions obtained by the propose d method converge numerically, have been clarified through numerical e valuations.