Optimization Design Of S Tube Valve For Fresh Concrete Pumping Based On DEM

Pumping construction is the most commonly used for concrete construction method. The pumping process is mainly pumping fresh concrete prepared by mixing station to the specified location through the pipeline pumping, so the pumping pipe plays a very important role in pump construction. while S tube valve is a component of pumping pipe of the most important, That is mainly used to connect the hopper and pumping pipeline. Whether the design is reasonable has a great influence on pumping process. With experiment and simulation,the main work of this paper as follows:(1)With the Bingham model in DEM, a general DEM(Discrete Element method) Model was established. Firstly the basic properties of sandstone are tested by some simple experiments, such as the rebound coefficient, friction coefficient and static friction coefficient, and a general discrete element model of fresh concrete is established. And then using V-box, the feasibility of discrete element software simulation of concrete is analyzed qualitatively, through the improvement of the slump test and L-box test experiment, the micro parameter of the model is calibrated. Finally, through the pressure type rheometer, the correctness of discrete element model is verified.(2)The pressure distribution of different pumping pipeline is analyzed. Using the DEM—FEM method, through the method of numerical simulation directly compared with the experimental, the correctness of the model under the same boundary conditions and initial conditions to do the simulation of pumping process is verified, the pressure loss in the pipeline is analyzed, finally, the biggest pressure loss pipeline- S tube valve found out.(3)Optimization of the pump S tube valve. Using the DEM model to simulate the process of pumping, With reference to the method of dimensional analysis, the influence factors was divided into operation parameters and structure parameters and optimize them. The main operating parameters including pumping speed, volume fraction of coarse aggregate, coarse aggregate shape; the level of structure size parameters mainly include pumping pipeline, pipeline radius and tribute pipeline distribution. And then using the DEM-FEM method to optimized the two kinds of parameters. Finally, the optimized S tube valve curve equation was given.