Deformation and stress analysis of cup on pipeline inspection gauge based on reverse measurement

The pipeline inspection gauge (PIG) is one of the most significant gauges in the field of oil-gas storage and transportation. It is essential to use PIG to clean and detect petroleum and natural gas pipelines. Predicting the deformation and stress distribution of the cup on the PIG is essential before pigging. To enhance these predictions, especially the deformation of the cup, a method for measuring the deformation of the cup based on reverse measurement was introduced and a novel finite element (FE) simulation model for investigation of the deformation of cups was proposed and verified in this paper. The point cloud data of the cup before and after entering the pipe can be obtained by the three-dimensional (3D) laser scanner. Comparing the obtained point cloud data can measure the deformation of the cup. In addition, a 3D FE model was created to predict the deformation of the cup and the effective stress on the contact area. The result shows that there is a linear relationship between circumferential deformation and interference, while there is a nonlinear relationship between axial deformation, effective stress, and interference. These results provide a better understanding of the complex behavior of PIG during pigging.