覆土阻力对挖掘机损伤输气管道的动力响应研究

Study on dynamic response of gas pipeline damaged by excavator with covering soil resistance

工程中管道挖掘损伤多为挖掘机具穿透土层后作用在管道上而导致。为确定覆土阻力下挖掘机对管道的损伤情况,利用ADAMS多体动力学软件,建立多体动力学仿真模型,再现挖掘过程,获取不同工况下有覆土阻力时管道所受挖掘荷载的时程曲线;最终将荷载时程曲线导入到ABAQUS有限元软件中,分析管道的动力响应情况。研究结果表明:单齿作用下管道承受的挖掘荷载的峰值是五齿作用下的1. 3～1. 9倍;与铲斗接触处的管道横截面的各项力学特征以接触点所在竖轴线为中轴线呈对称状态;挖掘荷载作用下,输气管道的Mises应力随着覆土厚度的增大而减小,且在覆土厚度变化量相同的情况下,覆土越深管道的Mises应力变化量越小。

The damage of pipeline caused by excavation in the engineering is almost due to the effect of excavator on the pipeline after penetrating the soil layer. In order to determine the damage situation of pipeline caused by the excavator with the covering soil resistance, a multi-body dynamics simulation model was established by using the ADAMS multi-body dynamics software to represent the excavation process, and the time-history curves of the bearing excavation load of pipeline with the covering soil resistance under different working conditions were obtained. The time-history curves of load were imported into the ABAQUS finite element software to analyze the dynamic response of the pipeline. The results showed that the peak value of the bearing excavation load of pipeline under the effect of single tooth was 1.3 - 1.9 times of that under the effect of five teeth. The mechanical characteristics of pipeline cross section at the position contacting with the bucket were symmetric with the vertical axis at the contact point as the central axis. Under the effect of excavation load, the Mises stress of gas pipeline decreased with the increasing thickness of covering soil, and under the same variation of the thickness of covering soil, the larger the depth of covering soil, the smaller the variation of Mises stress.