| Rainfall Simulation System(RSS) is necessary testing equipment in the experimental study on soil and water erosion and the preparation of soil and water conservation programs of development and construction projects. Its performance has direct impact on the credibility of the pilot trial. In this paper, failure mechanism of the "Stoppage" and "Slippery" of Oscillating Frequency Control Device(OFCD) in Trough-type Rainfall Simulation System(TRSS) have been deeply analyzed. Furthermore, The kinematics and dynamics mechanism on Controllable Overrunning Clutch(COC), which was the core part of the transmission system in TRSS, have been carried out in depth. Comprehensive Testing Platform(CTP) and Virtual Simulation Model(VSM), aimed at integrated testing and simulating on TRSS, have been designed. Theoretical approach, measured tools and simulation algorithm have been integrated together and complemented each other. It laid a good foundation for optimal design of TRSS. The main contributions of the paper are:1. The foreign and democratic development status and trends of RSS have been summarized. The development course and working principle of TRSS have been introduced. The key problems to be settled in TRSS have been described.2. Based on stress analysis of OFCD, the causes and influencing factors of the "Stoppage" and "Slippery" have been explained. By using the established OFCD model in ADAMS, the decisive factors have been extracted. According to the extracted factors, OFCD has been improved.3. The CTP of the Transmission System has been designed, which includes Torque Testing Device(TTD), Switch-pawl Force Testing Device(SFTD) and Frequency Fault Monitoring Device(FFMD). This platform aimed at comprehensive performance testing, fault diagnosis and simulation verification on transmission system.4. By using ADAMS, AMESim and Matlab/simulink, the transmission and hydraulic system model of TRSS has been established respectively. Joint Simulation of TRSS has been realized by using interactive interface between the simulation platforms. The relationship between simulation accuracy and efficiency has been evaluated. This model not only play the professional advantage of these simulation software, but also shorten the simulation time to the maximum extent.5. The kinematics and dynamics mechanism of COC in the event of releasing course, releasing state, engaging course and engaging state have been depicted separately. The formation mechanism of the pulsating load during releasing state has been explained emphatically. The torque and normal force between roller, out-ring and switch-pawl have been modeled. The influence of roller number on pulsating load has been simulated. It provided a direction for the optimization of COC. |
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