Research on Nonconstant and Discontinuous Pumping Characteristics of the Concrete Pump Truck

The nonconstant concrete flow due to the alternating pumping of the twin cylinder of the hydraulic pump will cause vibration of concrete pump trucks. Furthermore, the discontinuous pumping of concrete caused by inadequate suction and air doping will exacerbate the vibration. In order to study the effect of nonconstant and discontinuous pumping of concrete on the dynamic response and vibrational stability of the whole vehicle, multi-fluid pumping models with concrete-lubrication gas for straight and elbow pipes are established, respectively, and the boundary conditions of periodic pumping speed are taken into account to compare the rheological characteristics of concrete and the exciting force on the pipe wall under nonconstant pumping, discontinuous pumping and nonconstant discontinuous pumping conditions. Results show that the pipe pressure and the exciting force vary periodically with the pumping speed under nonconstant pumping conditions, and the peak-to-peak value of the pipe pressure and excitation for discontinuous pumping depend on the volume fraction and distribution state of the gas in the pipe.