Semi-active DAVI Design For Helicopter Main Rotor

In the aerospace industry, vibration of helicopter has been a big issue. Researchers have been trying various forms of vibration control from the very beginning of the development of helicopters. But unfortunately the problem of vibration of helicopter hasn’t been well solved while the development of other helicopter techniques. Thus it is becoming even a pressing issue. Existing techniques have shortcomings like low efficiency, big volume, heavy mass and so on. Designing and researching for better vibration isolator has its significant importance.This article mainly studied a new vibration isolator based on dynamic anti-vibration isolator and focusing isolator. First, principles of DAVI were combined with focusing isolator to create a new focusing DAVI theory. Its finite element model was built to testify feasibility of the theory. Optimization of one of the design varieties, concentrated mass, was conducted using Isight and Patran/Nastran. After the model was built, the dynamic model and its finite element model were built to study its isolating efficiency. Also, Catia model of the isolator was built. After optimization, the transfer rate of force is under 5%.When frequency of the load changes, transfer rate is almost impossible to stay this low. Considering that concentrated mass could move along the beam, and its position on the beam could affect hugely its efficiency under different stimulating frequency, a control system was introduced to enable the isolator a broad brand of working frequency with a relatively high efficiency. Matlab was used to simulate different situations. Results show that transfer rate can be controlled under 30%.This paper designed a semi-activ DAVI vibration isolator used on helicopter main rotor using theoretical research and finite element simulation and control simulation. The design’s feasibility was test and the paper met with its purpose.