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In order to reveal the mechanical behavior of short concrete columns reinforced with hybrid steel and glass FRP bars, 10 specimens were designed for eccentric compression tests. The effect of eccentricity and load–displacement/strain of the specimens was studied. Test results indicate that the damage process and failure mode of these hybrid RC columns was similar to those in the conventional steel-reinforced concrete columns. The mode of failure for all specimens is characterized as large eccentricity compression failure, and the ultimate bearing capacity of the columns decreases with the increase in eccentricity. However, the impact of the varying axial stiffness ratio between GFRP and steel bars on the bearing capacity can be considered negligible. In addition, based on theoretical analysis, two boundary states for distinguishing failure mode and the formulae for calculating ultimate bearing capacity in different failure modes of eccentrically loaded hybrid RC columns are proposed. The computed results agree well with test results. [ABSTRACT FROM AUTHOR]

Considering the requirements pertaining to the trafficability of off-road vehicles on rough roads, and since their roll stability deteriorates rapidly when turning violently or passing slant roads due to a high center of gravity (CG), an efficient anti-slip control (ASC) method with superior instantaneity and robustness, in conjunction with a rollover prevention algorithm, was proposed in this study. A nonlinear 14 DOF vehicle model was initially constructed in order to explain the dynamic coupling mechanism among the lateral motion, yaw motion and roll motion of vehicles. To acquire physical state changes and friction forces of the tires in real time, corrected LuGre tire models were utilized with the aid of resolvers and inertial sensors, and an adaptive sliding mode controller (ASMC) was designed to suppress each wheel's slip ratio. In addition, a model predictive controller (MPC) was established to forecast rollover risk and roll moment in reaction to the change in the lateral forces as well as the different ground heights of the opposite wheels. During experimentation, the mutations of tire adhesion capacity were quickly discerned and the wheel-hub drive motors (WHDM) and ASC maintained the drive efficiency under different adhesion conditions. Finally, a hardware-in-the-loop (HIL) platform made up of the vehicle dynamic model in the dSPACE software, semi-active suspension (SAS), a vehicle control unit (VCU) and driver simulator was constructed, where the prediction and moving optimization of MPC was found to enhance roll stability effectively by reducing the length of roll arm when necessary. [ABSTRACT FROM AUTHOR]

This study employs time-resolved particle image velocimetry technology to investigate the flow field characteristics of a double-wall jet structure under both stationary and rotating conditions. The jet rotation number range from 0 to 0.08, covering both clockwise and counterclockwise rotations, with a jet Reynolds number of 4000. The dimensionless jet-to-target spacing is 2. In order to elucidate the flow mechanisms based on experimental results and provide complementary insight, validated numerical simulations under conditions identical to the experiments were conducted. This paper considers average velocity and Reynolds stress and utilizes the proper orthogonal decomposition method to study flow characteristics. The results indicate that the rotation-induced Coriolis force, centrifugal force, and radial pressure gradient in the radial direction influence the jet to deflect. The pressure gradient generated by the centrifugal force weakens its effect, making the jet deflection primarily dominated by the Coriolis force. The deflection direction and degree of the jet differ with the rotation direction and increase with the rotation number. When the rotation direction is reversed, differences in the direction of the force acting on the fluid lead to variations in the secondary flow structures of the jet; the secondary flow structures within the impingement holes exhibit two-vortex or four-vortex structures under counterclockwise or clockwise rotation, respectively. At the highest rotation number, jet deflection intensifies mixing with the surrounding fluid, resulting in a reduction of about 30% in the velocity peak compared to the stationary state but an increase of approximately 0.6 times in turbulent kinetic energy. [ABSTRACT FROM AUTHOR]