Abstract:

After the motion process of string bead was analysed,
motion equation of all partles in the string bead wire was established when string bead impact pipe wall.Displacement and velocity variation patterns of all partles in string bead wire were simulated with finite element transient dynamics analytical method，and additive stress of string bead wire in different axial position was calculated．Through test observation，much strenuous impact is generated in the course of cutting process，the cutting time prolonges greatly，and the cross-section level degree is much low，comparing with cutting combined pipe.Test demonstrates that increasing string bead quantity of per meter
string bead wire can decrease impact action．

Key words: underwater cutting；diamond wire saw；string bead wire；monolayer pipeline；impact

摘要：

在分析了切割单层管道时串珠的运动过程后，建立了串珠与管壁冲击瞬间串珠绳内部各质点的运动方程。采用有限元瞬态动力学分析方法，仿真了串珠绳内部各质点的位移和速度的变化规律，并计算了冲击瞬间串珠绳轴线各处的附加动应力。试验研究表明：与切割复合管道相比，切割单层管道时，切割过程中发生了较剧烈的冲击，切割时间大大延长，切割后的断面水平度比较低；适当增加每米串珠绳上串珠个数可以减轻冲击作用。

关键词: 水下切割；金刚石绳锯机；串珠绳；单层油气管道；冲击