Semi-Active Control Of Magnetorheological Shock Absorber Subjected To Impact Load

With the development of structure design and the applications of hi-technology,more and more impact issues within high impact loading occurs in real applications. Itis familiar in the aeronautic and aerospace engineering, military engineering,transportation and civil engineering. The researches on vibration reduction underimpact load have been proved to having a promising future and should be paid moreattentions. Magnetorheological (MR) shock absorber is a smart devices, which has theadvantages of good controlibility, wide dynamic range, rapaid reponse time andlow-energy cost. It is a promising device in vibration control. Till now, lots ofresearches have been carded out to explore the structure design, dynamic andvibration control when MR shock absorber subjected to random load, such as vehiclesuspensions and anti-wind-vibration in civil engineering. However, little explorationhas been focus on the dynamic characteristics and vibration control when MR shockabsorber subjected to impact load.In this dissertation, theoretical analysis, dynamic simulation and test verificationwere used to investigate the dynamic performance and vibration control of MRshock absorber under impact load. The main contributions of this dissertationinclude the followings:1. The significance of vibration control under impact load is introduced inchapert one of this dissertation. The history and updated development of MRtechnology is reviewed. Several applications of MR technology arespecified in the military engineering. Moreover, some deficiencies, such asthe character of MR fluids and control methold are brought forward. Thispaper also summarized the main tasks of this dissertation.2. Using the theory of hydrodynamics and the rheology govern equations of MRfluids, Bingham model and erschel-Bulkley model were deduced to explainthe dynamic behavior of MR shock absorber. For the dynamic of MR shockabsorber under impact load, an inertia factor was introduced to Binghammodel and Herschel-Bulkley model, which leading to two revised model,named as Bingham-Inertia model and Herschel-Bulkley-Inertia model.3. Dynamic characteristics of MR shock absorber subjected to impact andimpulsive load is investigated using the test rig we designed. The parameter recognization was accomplished to revise the Bingham-Inertia model andHerschel-Bulkley-Inertia model.4. Three control stratigies, they are on-off control, PID control and fuzzy logiccontrol are designed using the MATLAB and Simulink. According to thepractical need of vibration control under impact load. Three control metholdswere revised to be pressure-feedback ones. To evaluate the control effect ofthe control metholds, a hardware-in-loop simulation and test was finished.5. A specific introduction of impact test system was done in last chapter. Somedetail for practical use is explained.Finally, the work of this dissertation was concluded. The innoviations andcontributions of this work were introduced. And a/so, the potential issues of thisresearch were pointed out.