Dynamics of a large-diameter and multi-section pipeline inspection gauge when crossing obstacles

The dynamic behavior generated by the collision between multi-section Pipeline Inspection Gauge (PIG) and obstacles inside the pipeline is highly complex. A double section PIG is connected through a double universal joint and is divided into front section and rear section. The transmission patterns of vibration and their effects between the two sections are not yet fully known. This study investigates the vibration response and transmission law of a large-diameter and multi-section PIG when crossing obstacles. By constructing a high fidelity, full size, full factor nonlinear multi-system dynamic model of double section Φ1219mm PIGs, the changes in vibration acceleration of the PIG under different operating speeds are simulated. A full-size traction experimental setup has been built. The simulation results are compared with traction experiment and field experiment. The findings indicate that the sudden change in axial acceleration caused by collision is mainly concentrated in the frequency range of 0–50 Hz.