Aiming at the problem of low-frequency vibration of the hydraulic pipeline, a new type of semi-active damping magnetorheological (MR) damping clamp structure is designed. The structure size and material of the MR damping clamp were determined. The control model of the vibration damping system was established, and the control method combining fuzzy control and Proportional-Integral-Derivative (PID) control was used to carry out the numerical simulation, which proved that the fuzzy–PID control algorithm is effective and stable. The results show that the MR damping clamp proposed in this paper can effectively suppress the axial displacement and acceleration of the hydraulic pipeline in the excitation frequency range of 1 Hz~10 Hz. This research provides a new technical approach for low-frequency vibration control of hydraulic pipelines.

Low-frequency vibration control is a crucial challenge within the realm of fluid physics, and in this paper, a novel magnetic compound fluid (MCF) has been developed to produce a magnetic fluid nonlinear energy sink (MF-NES) with optimum energy consumption efficiency. The mixed doping of bi-dispersed nano-sized iron particles (NIPs) and micrometer-sized carbonyl iron particles (CIPs) can generate a load-bearing structure between the inertial mass and the MF-NES shell with a reduced friction coefficient. The effectiveness and sensitivity of the MF-NES mechanism is significantly enhanced, particularly in responding to low frequency vibrations. To predict and quantify the friction coefficient of the MF, a novel hybrid approach combining data handling and a genetic algorithm model was developed and rigorously validated through empirical data obtained from the experiments and demonstrated that the bi-dispersed NIPs/CIPs MCF had a notably lower friction coefficient, making it adept at responding to low-frequency and even ultra-low-frequency vibrations.