構造物振動 低減을 위한 LOA의 制御에 관한 硏究 = A Study on the Control of Linear Oscillatory Actuator for Structural Vibration Reduction

다국어 초록 (Multilingual Abstract)

Recently increasing flexibility and low damping characteristics of large structures have made the structures susceptible to large vibration levels under harsh environmental loads such as earthquakes, winds, and mechanical excitations. Therefore, higher performance control systems to reduce the vibration levels are demanded more than any time in the past. In this paper, the active vibration control system using a linear oscillatory actuator (LOA) is studied to suppress structural vibration.
A voice-coil-type LOA having the moving mass of 23㎏ weight is designed and fabricated for good linearity and high performance. The LOA consists of permanent magnets with high specific energy as the stator, a nonmagnetic hollow rectangular structure wrapped the coil around, and an iron core as a pathway for magnetic flux. When the coil is fed with alternating current, a oscillating force is produced to the active mass connected to the mover in the magnetic field generated by the magnets. The LOA has relatively simple structure of almost maintenance free, compared with other actuators such as a hydraulic actuator.
Performance tests are carried out on the test structure subjected to sinusoidal and random base excitations. From these tests, it is confirmed that the acceleration level of the test structure is drastically reduced near the resonant region.