Abstract:A loading system based on electro-hydraulic proportional control is designed. To meet the requirement that the hydraulic loading system of the test machine can linearly control the loading force of the test bridge deck, a loading mechanism is designed, which makes the error on loading force less than 0.2% when the maximum tire deformation occurs. Meanwhile, a simulation model of the loading system is established to simulate and further analyze the dynamic and static characteristics. Finally, the static and dynamic characteristics of the loading system are verified by the static loading experiment and the sinusoidal loading experiment with the same amplitude at different frequencies, respectively. The experimental results show that the loading system can achieve linear loading between the control voltage and the loading force, and satisfy the constant loading within 15 000 kg and under the sinusoidal loading condition when the amplitude is less than 1 500 kg and the frequency is within 2.0 Hz.