Influence of uncertainty factors on the dynamic characteristics of magnetorheological damper

Abstract

The magnetorheological damper (MRD) is a kind of energy dissipation device, which converts vibration mechanical energy into self-heat energy during operation. The dynamic performance of MRD is affected by uncertain factors such as temperature and external magnetic field. In this paper, basing on the temperature rise theory and external magnetic field interference theory of MRD, it analyses the influence of temperature effect and external magnetic field on the dynamic performance of MRD. Under sinusoidal excitation, the internal temperature field and magnetic field distribution of MRD are simulated by COMSOL, and it calculates the changes of temperature and magnetic field in MRD by the conditions of input current of 0.4A, 0.8A and 1.2A. The temperature rise and external magnetic field test are carried out. Under the same input current, the temperature rise of the outer wall of the cylinder is measured. The results show that the input current increases, the temperature rise of MRD increases, and the temperature of MRD increases, the output damping force decreases obviously. When the input current is 0.4A, the temperature of MRD rises to 40℃, the maximum output damping force decreases by 11.2%, and the current is 1.2A, the maximum output damping force decreases by 18.6%. When external magnetic field is applied, the output damping force of MRD increases. The magnetic induction intensity of the external magnetic field increases from 10mT to 30mT, when the incoming current is 0.4A, the maximum output damping force increases by 5.9%, and the current is 1.2A, the maximum output damping force increases by 5.1%. Therefore, applying external magnetic field to compensate the decreasing value of output damping force caused by temperature rise effect has a certain effect. The results show that the variation trend of theoretical analysis, simulation calculation and experimental verification is consistent.