水下链铲式挖沟机切削土体有限元分析

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。

水下绞笼式挖沟机机械开挖数值分析

海底管道是海洋油气田开发中输送油气资源的重要设施,为维持其自身安全和在位稳定性,必须将海底管道埋设到预定的深度,海底挖沟机是埋设海底管道和电缆的重要设备。采用非线性流固耦合算法,对机械绞笼切削土体进行了深入求解,分析了绞笼开沟过程中的切削荷载变化规律,研究了开沟过程中土体的变形规律与破坏机理。数值计算结果表明:开沟过程中绞笼的切削荷载随着绞笼转速的增大而减小;绞笼刃板上钭齿的刚度与摩擦特性对切削荷载影响较为显著;绞笼内部螺旋导料板也较为明显地影响着切削荷载。最后,针对数值计算结果,给出了绞笼切削荷载计算公式,能够较为准确、高效地对绞笼式挖沟机切削荷载进行计算,在工程应用方面具有一定的参考价值。

Characteristics of different rocks cut by helical cutting mechanism

To research the loading charactefistc of rocks with different structures cut by helical cutting mechanism （HCM）, three different structures of rock （hard-soft-hard rock, soft-hard rock and soft-hard-soft rock） were built. And each type model was further divided into three types when the experiments were carried out. To reduce the errors of cutting load caused by manually configured rock in each test, the cutting load of soft rock was taken as a benchmark, and the differences of the cutting load of the different structures of rocks and the soft rock were used to reflect the cutting load change rules of the HCM. The results indicate that, the cutting load of only the HCM top cutting hard rock is larger than that of only the HCM bottom cutting hard rock for dextral HCM, and the cutting load fluctuation is larger, too. However, when the top and the bottom of the HCM cutting hard rock simultaneously, its cutting load is the largest, but the cutting load fluctuation is the least. And the HCM cutting load increment is increased linearly with the increase of rock compressive strength. The HCM cutting load increment is increased exponentially with the increase of hard rock cutting thickness.