Abstract: Horizontal vibration shakers 21a and 21b are disposed opposite to each other on both sides of a vibration table 4, and either of the horizontal vibration shakers, e.g. 21a is arranged vertically movable so as to produce a positional difference (offset) with respect to a horizontal vibration axis 63 of the other horizontal vibration shaker 21b. When it is supposed that an accelerated velocity appears upwards on the left side of the vibration table 4, while another accelerated velocity appears downwards on the right side of the vibration table 4 as a result of generation of a rotational mode M, one of the horizontal vibration shakers, e.g. 21a, is elevated to produce the positional difference (offset) with respect to the horizontal vibration axis 63 of the other opposed horizontal vibration shaker 21b.

Abstract: Horizontal vibration shakers 21a and 21b are disposed opposite to each other on both sides of a vibration table 4, and either of the horizontal vibration shakers, e.g. 21a is arranged vertically movable so as to produce a positional difference (offset) with respect to a horizontal vibration axis 63 of the other horizontal vibration shaker 21b. When it is supposed that an accelerated velocity appears upwards on the left side of the vibration table 4, while another accelerated velocity appears downwards on the right side of the vibration table 4 as a result of generation of a rotational mode M, one of the horizontal vibration shakers, e.g. 21a, is elevated to produce the positional difference (offset) with respect to the horizontal vibration axis 63 of the other opposed horizontal vibration shaker 21b.

Abstract: A vibration testing apparatus which is minimized in size and capable of being assembled with ease includes a vibrating section (11), a vibration generator (10), and a transmitting section (21) for transmitting vibrations from the vibration generator (10) to the vibrating section. The transmitting section (21) is formed with a pair of opposed parallel pressure-receiving plates (23, 24) that are orthogonal to the direction of vibrations, with the vibrating section (11) interposed between the pressure-receiving plates. The vibrating section (11) is formed with pressure-bearing surfaces (14) in opposed parallel relation to the pair of pressure-receiving plates (23, 24). High pressure fluid is fed into clearances (16), defined between the pressure-receiving plates (23, 24) and the pressure-bearing surfaces (14), to form a static pressure bearing. The pressure-receiving plates (23, 24) are clamped by a connecting member (25) under a load whose value enables the static pressure bearing to function as a spring.