Apparatus and method for vibratory testing

A vibrator system for use with a vibratory testing table, the vibrator system comprising:

• at least one vibrator having a sealed body with first and second ends and defining a cavity therein, the cavity having first and second ends;
• a first air passage in the sealed body near the first end of the body, the first air passage configured to allow gas to flow to and from the first aid of the cavity;
• a second air passage in the sealed body near the second end of the body, the second air passage configured to allow gas to flow to and from the second end of the cavity;
• a piston within the cavity and moveable between the first and second ends;
• a four-way solenoid valve having an in port, two in/out ports and an exhaust port, the first air passage of the vibrator connected to a first in/out port and the second air passage connected, to a second in/out port;
• a pneumatic air supply connected to the in port of the four-way solenoid valve;
• and
• a controller connected to the four-way solenoid valve, the controller capable of controlling the four-way solenoid valve to allow air from the pneumatic air supply to the vibrator in bursts, a burst moving the piston to impact with the body of the vibrator at one of the ends of the cavity and a subsequent burst moving the piston to impact with the body of the vibrator at the opposite end of the cavity, whereby the frequency of the impacts is controlled via the controller.

A method of controlling the movement of a piston of a vibrator as part of a vibratory testing apparatus, the method comprising:

• providing a vibratory testing apparatus including at least one vibrator, the vibrator including a piston enclosed within a cavity of the vibrator;
• providing a power system for powering the vibrator attached to the vibrator;
• providing a controller attached to the power system, the controller capable of controlling the power system;
• activating via the controller a first burst of power from the power system to the vibrator, whereby the piston is moved within the cavity to impact the vibrator at a first amplitude;
• and
• activating via the controller a second, burst of power from the power system to the vibrator, whereby the piston is moved within the cavity to impact the vibrator at a second amplitude, wherein the second amplitude is independent of the first amplitude;
• whereby the controller controls the frequency of impacts by controlling the amount of time between sending the first and second control signals.