Abstract: A method for focussing vibrational energy upon a target volume within a surrounding contiguous medium imparts high intensity energy upon the target volume from low level energy sources. A plurality of standing compression waves are established within the medium along corresponding longitudinal axes between opposing pairs of coordinated transducers. The target volume is located at the common intersection of the axes of the standing compression waves. Opposing pairs of transducers are positioned from each other at a distance equal to an integer multiple of half wavelengths of the corresponding standing wave therebetween. The phase angle of each standing compression wave is regulated so as to cause each wave to be at its maximum intensity (amplitude) within the target volume at the point of common intersection with the other standing waves.

Abstract: An apparatus for focussing vibrational energy upon a target volume within a surrounding contiguous medium imparts high intensity energy upon the target volume from low level energy sources. A plurality of standing compression waves are established within the medium along corresponding longitudinal axes between opposing pairs of coordinated transducers. The target volume is located at the common intersection of the axes of the standing compression waves. Opposing pairs of transducers are positioned from each other at a distance equal to an integer multiple of half wavelengths of the corresponding standing wave therebetween. The phase angle of each standing compression wave is regulated so as to cause each wave to be at its maximum intensity (amplitude) within the target volume at the point of common intersection with the other standing waves.

Abstract: Vibrational energy introduced into plastic concrete structures, such as concrete slabs, decks and similar or related concrete structures, at or near the natural resonant frequency of the liquid concrete mass, expedites the consolidation and setting of the concrete. A vibrating apparatus imparts controlled vibrations either onto the surface or beneath the surface of the concrete mass in sequential stages, the frequency of vibrations generally increasing with each subsequent stage, corresponding to the increase in the natural resonant frequency of the progressively-narrowing liquid concrete at the top of the structure. The relatively more consolidated and more dry concrete (typically near the bottom of the slab) is substantially unaffected by the non-resonant frequencies vibrations. In one modification, sensors determine the resonant frequency of the liquid concrete mass during each pass of the vibrator apparatus, and the frequency of the vibrating member is automatically adjusted, accordingly.

Abstract: Vibrational energy introduced into plastic concrete structures, such as concrete slabs, decks and similar or related concrete structures, at or near the natural resonant frequency of the liquid concrete mass, expedites the consolidation and setting of the concrete. A vibrating apparatus imparts controlled vibrations either onto the surface or beneath the surface of the concrete mass in sequential stages, the frequency of vibrations generally increasing with each subsequent stage, corresponding to the increase in the natural resonant frequency of the progressively-narrowing liquid concrete at the top of the structure. The relatively more consolidated and more dry concrete (typically near the bottom of the slab) is substantially unaffected by the non-resonant frequencies vibrations. In one modification, sensors determine the resonant frequency of the liquid concrete mass during each pass of the vibrator apparatus, and the frequency of the vibrating member is automatically adjusted, accordingly.