水下链铲式挖沟机切削土体有限元分析

Finite element analysis of soil cutting by underwater chain shovel trencher

海底管道通常需要埋在海底泥土里,链铲式挖沟机是海底挖沟设备的一种。采用流固耦合非线性计算方法,利用CEL法对链铲式挖沟机海床作业过程进行了数值计算,分析了链铲开沟过程中的机械切削荷载变化规律,研究了开沟过程中钭齿周围土体的变形规律与破坏机理。数值计算结果表明:开沟过程中钭齿的切削荷载随着切削速度的增大而减小;钭齿的刚度与表面摩擦特性对切削荷载影响较为显著。最后,针对数值计算结果,给出了较为实用的切削荷载计算公式,能够较为准确、高效地对挖沟机切削荷载进行计算,在工程实际应用和深入理论分析方面具有一定的参考价值。

Subsea pipelines usually need to be buried in undersea soil.The chain shovel trencher is a kind of submarine trench excavator.A nonlinear fluid-solid coupling calculation method is used.The coupled Eulerian-Lagrangian(CEL)method is employed to calculate the operation process of the chain shovel mechanical trencher on the seabed,the variation law of the mechanical cutting load in the trenching process of the chain shovel trencher is analyzed,and the deformation law and failure mechanism of soil around the cutter in the trenching process are investigated.The numerical calculation results show that the cutting load on the cutter decreases with an increasing cutting speed.Cutter stiffness and surface friction characteristics have significant impacts on cutting load.Finally,according to the numerical calculation results,this paper presents a practical cutting load calculation formula,which can calculate the cutting load on the trencher accurately and efficiently and has a high reference value for engineering application and in-depth theoretical analysis.