An articulated frame steered vehicle model with torsio-elastic suspension is established in Adams/View. The model considered the influence of the hydraulic steering system on the yaw stability of articulated vehicles, thus, the hydraulic steering system is formulated and modeled in MATLAB/Simulink. The ride and roll/yaw stability of the vehicle model is investigated via co-simulation of Adams and Simulink. The Adams vehicle model is verified based on the vibration acceleration responses near the seat position at constant forward speeds. The hydraulic steering system model is validated through the steady-state steering maneuver. Relative ride performance of unsuspended and fully suspended vehicle is investigated in terms of unweighted and frequency-weighted root-mean-square accelerations. The roll and yaw stability of vehicle model with and without suspension at loaded and unloaded conditions are subsequently analyzed in terms of roll angle, roll safety factor, lateral acceleration, critical speed, and so on. The results show that the torsio-elastic suspension can efficiently reduce the vibrations of the vehicle, and the articulated frame steer vehicles applied with torsio-elastic suspension yield slightly lower roll/yaw stability but substantial reductions in the ride vibration levels. The results provide some reference for the suspension and steering system design of articulated engineering vehicle.

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To reduce the vibration and shock of powertrain in the process of engine key on/off and vehicle in situ shift, a novel semi-active hydraulic damping strut is developed. The purpose of this paper is to study and discuss the dynamic stiffness model of the semi-active hydraulic damping strut. In this study, the dynamic characteristics of semi-active hydraulic damping strut were analyzed based on MTS 831 test rig first. Then, the dynamic stiffness model of semi-active hydraulic damping strut was established based on 2 degrees of freedom vibration system. In this research, a linear, fractional derivative and friction model was used to represent the nonlinear rubber bushing characteristic; the Maxwell model was used to describe the semi-active hydraulic damping strut body model; and the parameters of rubber bushing and semi-active hydraulic damping strut body were identified. The dynamic stiffness values were calculated with solenoid valve energized and not energized at amplitudes of 1 mm and 4 mm, which were consistent with experimental results in low-frequency range. Furthermore, the simplified dynamic stiffness model of the semi-active hydraulic damping strut was discussed, which showed that bushing can be ignored in low-frequency range. Then, the influence of equivalent spring stiffness, damping constant, and rubber bushing stiffness on the stiffness and damping capacity of the semi-active hydraulic damping strut were analyzed. Finally, the prototype of the semi-active hydraulic damping strut was developed and designed based on the vehicle in situ shift and engine key on/off situations, and experiments of the vehicle with and without semi-active hydraulic damping strut were carried out to verify its function.

A 2-D numerical simulation model was established based on a small-sized metal hydride storage tank, and the model was validated by the existing experiments. An external cooling bath was equipped to simulate the heating effects of hydrogen absorption reactions. Furthermore, both the type and the flow rate of the cooling fluids in the cooling bath were altered, so that changes in temperature and hydrogen storage capacity in the hydrogen storage model could be analyzed. It is demonstrated that the reaction rate in the center of the hydrogen storage tank gradually becomes lower than that at the wall surface. When the flow rate of the fluid is small, significant differences can be found in the cooling liquid temperature at the inlet and the outlet cooling bath. In areas adjacent to its inlet, the reaction rate is higher than that at the outlet, and a better cooling effect is produced by water. As the flow rate increases, the total time consumed by hydrogen adsorption reaction is gradually reduced to a constant value. At the same flow rate, the wall surface of the tank shows a reaction rate insignificantly different from that in its center, provided that cooling water or oil coolant is replaced with air.

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