Exciter System Performs Large-Scale Modal Testing

MB Dynamics’ Modal 1000 exciter system for large-scale modal and structural testing can excite sine forces of up to 4000N (900 lbf), with a 2-in. (50-mm) peak-to-peak stroke and 1. 5 m/s peak velocity (60 in./s), at frequencies from dc to 2 kHz. Both thermal shutdown protection and overtravel control are provided as standard features.

 

The armature design of the MB Modal 1000 incorporates a “weak” suspension. The suspension may be fine-positioned to the test article using dc current. This is a particularly useful feature within lower-frequency response applications, such as ground vibration testing, where a dc-coupled exciter/amplifier may be in use. The armature’s lower weight further minimizes mass loading effects on the test article while reducing force drop-off at resonance. This avoids test article contamination during parameter extractions at each natural frequency. Additionally, the use of weak suspension means that the armature applies no extra force. Exciter dynamics are therefore de-coupled from measured test article dynamics for improved measurement data integrity.

 

The MB Modal 1000 exciter system may be used as either a stand-alone unit or paired with an MB P-Series power amplifier. The amplifier is housed within a 750-mm high, 19-inch rack cabinet and operates from 208-240 Vac single-phase power. Supporting stingers, used to apply forces to the test article without exciter interference, are also available. Options include the capability to operate supporting amplifiers directly from a PC, allowing for amplifier positioning closer to the exciters. For more information, pursue and peruse the Modal 1000 exciter system datasheet, call 216-292-5850, and/or email [email protected].