Tunable Proof Mass Actuator Based on a Pendulum Structure

摘要

Proof mass dampers are currently used in aircraft structures, but are not active, which introduce performance limitations. Proof Mass Actuators based on spring-mass structures are an interesting technique for active vibration control, but it is difficult to design them for operation below 100 Hz, especially if high dynamic forces are required. The proof of concept of a Tunable Proof Mass Actuator (TPMA) based on a pendulum structure has been assessed into the Mesema FP6 EC project targeting an Helicopter application. This pendulum structure allows achieving a very low resonant frequency (4 to 20Hz) associated with large inertial forces (>1kN) due to large vibration amplitude (10mm). To obtain a tunable resonant frequency, an internal actuator modifies the TPMA pre-load force. Two types of internal pre-load actuators are compared: An Amplified Magnetostrictive Actuator (AMA) and an Amplified Piezoelectric Actuator (APA). In both cases, the tunability has been observed, each type offering different advantages. This novel concept opens a new field of possibilities for making very low frequency semi active dampers or dynamic vibration absorbers for aircraft, helicopters and civil engineering.