Study on Dynamics Analysis and Application of Vibration Modal Testing of Suspension Cable Structure Based on MEMS Sensor

Abstract

The large span suspension structure is easy to generate larger vibration due to its smaller stiffness. For this problem, a finite element modal analysis method that considers the effect of initial pre-stress is proposed. The finite element model of the structure is established by using Link10 unit of the finite element analysis software ANSYS. Then the first four order natural frequency and vibration mode under different initial pre-stress is solved by the subspace iterative method. And the experimental test system based on MEMS sensor is designed to analyze the layout of test points and exciting vibration mode of the structure. The test system measures the inherent frequency and the first two order vibration mode under the action of different pre-stress. The results show that the numerical analysis results are basically consistent with the experimental results and the inherent frequency of the structure distributes in the plexus intensive form. And the inherent frequency of the structure is related to the pre-stress. The bigger the stiffness of the structure, the greater the inherent frequency is. It proves that the theoretical analysis results are correct and the experiment test system can be used in the structural dynamic test.