Mechanical Analysis And Numerical Simulation Of Soil Cutting By Draghead Teeth

Trailing suction hopper dredger(TSHD) has been widely used for the advantage of working without hindering navigation, and it can complete the whole process operation including self-propelled, excavation, shipment, reclamation. It is essential to study soil cutting process for the sake of improving the efficiency of draghead. In this paper, the process is in-depth researched by the methods of mechanical analysis and numerical simulation.Firstly, three-dimensional soil cutting mechanical models based on passive earth pressure theory are analyzed and compared to provide reference for results obtained in numerical simulation method. As to the large deformation of soil elements in the process of cutting, the traditional method will cause the iteration divergence, so the approaches of Lagrange with element deletion technique and arbitrary lagrangian eulerian are introduced, combined with a MAT147 material constitutive model which considers soil visco plastic characteristics, and the process is simulated by utilizing dynamic explicit algorithm of LS-DYNA software. The features of soil chip configurations, stress and strain distribution, cutting force are analyzed respectively, which confirm the reliability of ALE method in handling element large deformation.Further study of multi-tine interaction and pre-cutting effect caused by high pressure jet has been carried out. Mechanical models are established on the basis of Godwin’s modified soil failure outline. Specific cutting force acted on unit soil failure cross section is minimized to seek the optimal arrangement of draghead teeth and jet nozzles, and the numerical simulations are also conducted to analyze cutting force at different arrangement conditions.