The purpose of this research is reducing the acceleration level at the steering wheel in engine idling state. In a specific case, the vibration of steering wheel is often magnified due to resonance between the first natural frequency of T-beam and engine idling speed. By using SDM(structural dynamics modification) method, the first natural frequency of T-beam is raised and its vibration is reduced.
To perform the SDM, two methods are used in this research. first is the finite element method, and the other is FRF synthesis method. The FEM is based on numerical method while the other is based on experimental method. Using FEM, more dominant regions to change the fundamental natural frequency were searched then the FRF synthesis method is used to find the most sensitive position for applying SDM to raise its natural frequency. This procedure can reduce the test efforts for obtaining FRFs. In conclusion, by chaining the fundamental natural frequency of the T beam, the steering wheel vibration level can be reduced as much as 76% at engine idling state.
