To provide sufficient damping torque performance for heavy tracked vehicle’s suspensions, the design of a novel high-torque rotary magnetorheological (MR) damper with a parallel plate channel, referred to as PPCRMRD, is presented and the prototype of the PPCRMRD is manufactured. The theoretical model of the PPCRMRD considering the Hybrid magnetic fields effect and leakage effects is proposed. The max damping torque and controllable damping torque of the PPCRMRD are tested on the established experimental setup based on MTS rotary test system and compared with the theoretical results based on the proposed theoretical model, the theoretical model ignoring leakage effect and Bingham plastic model respectively. Under the sinusoidal excitation of 0.05 Hz and amplitude of 35°, compared with the theroetical model without considering the leakage gap and the Bingham plastic model, the maximum error of the proposed model is reduced by 11.08% and 40.66%. The tested max damping torque and controllable damping torque of the PPCRMRD under sinusoidal excitation with an amplitude of 35° and frequencies of 0.1 Hz are as high as 2677 and 1711 N m. The research results show that the principle of the PPCRMRD can provide sufficient damping torque as well as a wide range of controllable damping torque and the proposed theoretical model of the PPCRMRD can describe and predict its damping torque performance precisely.

A 6-DOF vibration isolation system with magneto-rheological damper (MRD) based on Stewart mechanism was designed to reduce the mechanical vibration more effectively. To make the isolation system perform well, an effective control method was also proposed. Using the linear multibody systems transfer matrix method (MSTMM), the dynamic model of the MRD 6-DOF vibration isolation system was established to obtain the dynamic characteristics. Firstly, based on the test mechanical property of magnetorheological damper, the electromagnetic coupling model of magnetorheological damper was established. Secondly, the transfer equation of 6-DOF vibration isolation system was established by linear MSTMM. And the state space equation was derived using the modal superposition method, which was based on the augmented eigenvector and body dynamics equation. Thirdly, the linear quadratic Gaussian control method of MRD 6-DOF vibration isolation system was designed. Finally, the numerical simulation was carried out. The results showed that MRD 6-DOF vibration isolation system with optimal control improved the dynamic performance of mechanical equipment effectively. Compared with passive vibration isolation system, the translation of the vibration isolation system in the X, Y, and Z directions, as well as the rotation around the X axis, Y axis and Z axis were reduced by 51.85%, 58.71%, 64.43%, 75.43%, 66.45% and 52.87%, respectively. Similarly, the percentage drops were 50.00%, 56.16%, 34.94%, 53.09%, 38.14% and 46.76% compared to the PID control based vibration isolation system, respectively. The established dynamic model and control strategy provided theoretical basis for relevant vibration isolation tests.

This paper presents the modeling and experimentation of a three degrees of freedom (3-DOF) piezo-actuated mechanism. The displacements of the piezoelectric stack actuators are amplified with lever mechanisms to achieve large displacement output. In order to accurately model the mechanism, a comprehensive model, which uses the transfer matrix method to describe the dynamics characteristics and the modified Bouc–Wen hysteresis operator to represent the hysteresis, is presented. Ultimately, the proposed comprehensive model of the mechanism is experimentally investigated for its performance. Experimental results show that the proposed comprehensive model can accurately portray the hysteresis and dynamics characteristics of the 3-DOF piezo-actuated mechanism.