Vibration Screening with Wave Barriers

Various forms ofwa ve barriers ha ve been used for more than 50years to reduce the amplitude of vibrations entering a region needing protection from excessive vibrations. The design of these barriers was at first based only on trial and error, but with a better understanding of wave propagation, design of these barriers was reduced mainly to a matter of determining the economic feasibility of the optimum barrier. Optimum barriers were shown to be void regions on the order of one Rayleigh wavelength deep. Open or void trench barriers are desirable but almost unachievable. Now, as we enter the 21st century, other choices are available from air-filled pillows to solid barriers that provide sufficient impedance mismatch to be effective barriers. Basic wave barrier principles including selection of dimensions and recent developments describing alternative barriers are presented.