Maximum Deflection Prediction Method for Plastic Large Deformation of High-energy Pipelines under Impact Load

When high-energy pipelines under the action of impact loads, the structure will subject to large deflection deformation. In order to predict the maximum deformation deflection of high-energy pipelines, a membrane force factor applicable to the structure was derived based on the membrane force factor method (MFM). A more convenient calculation method than traditional methods for mid-span deflection was established, and its accuracy was verified by comparing it with numerical simulation results and experiment results. The research results indicate that MFM has a high accuracy in predicting the deflection of pipeline structures; The magnitude of mid-span deflection is controlled by variable factors. The mid-span deflection increases with the increase of impact load and pipeline length, and decreases with the increase of plastic ultimate bending moment. The predicted deflection of pipelines with high degree of ellipticity is larger than the actual situation beacuse of MFM not taking into account the energy dissipated by section collapse. However, due to the support of high-energy fluid inside the pipeline, the collapse effect of the high-energy pipeline is not obvious. Therefore, this method can be used to predict the large deflection deformation of high-energy pipelines. For pipelines with high degree of collapse, the MFM prediction results are modified by combining the collapse model, which greatly improves the accuracy of the prediction method.