坠物撞击海底管道损伤的BP神经网络预测模型

为预测坠物撞击饱和黏土海床上海底管道的损伤，建立了坠物撞击下饱和黏土海床与海底管道相互作用的动力有限元模型，结合海底管道实际工作条件的变化范围，分析坠物撞击能量、管道直径、壁厚、钢材等级、内压、海床土不排水抗剪强度6个参数对海底管道损伤的影响规律，将6个参数作为输入层参数，以管道损伤作为输出参数，将数值模拟结果作为训练样本，通过学习和训练构建形成了海底管道损伤预测的BP神经网络模型。研究结果表明：坠物撞击能量越大，管道损伤越大，管道损伤增长速率随坠物撞击能量的增大而趋缓；管道直径、壁厚、内压、管道屈服强度增加，管道损伤减小；饱和黏土海床不排水抗剪强度越大，管道损伤越大。建立的海底管道损伤BP神经网络预测模型，仅需要坠物撞击能量、管道直径、壁厚、钢材等级、内压和海床土不排水抗剪强度6个参数，模型简单、便捷，能够较好地预测饱和黏土海床海底管道受坠物撞击的损伤，数值算例涵盖了常见饱和黏土海床海底管道的工作条件，具有很好的适用性，为海底管道损伤预测提供了新思路。

Damage predictive model of submarine pipeline impacted by falling object based on BP neural network

In order to predict the damage of submarine pipeline on saturated clay seabed by falling objects, a dynamic finite element model of interaction between saturated clay seabed and submarine pipeline under the impact of falling objects was established. The influence of six parameters, namely, energy of falling objects, diameter of the pipeline, wall thickness, grade of the steel material, internal pressure, and undrained shear strength of seabed soil on the damage of the submarine pipeline was analyzed by combining with the range of changes of the actual working conditions of the submarine pipeline. Taking the six parameters as input parameters, the damage of pipeline as output parameters, and the numerical simulation results as training samples, a BP neural network model for submarine pipeline damage prediction was constructed through learning and training. The results show that the larger the impact energy of the falling object is, the larger the pipeline damage is, and the pipeline damage growth rate tends to slow down with the increase in the impact energy of the falling object. The increase in pipeline diameter, wall thickness, internal pressure, and the pipeline yield strength leads to a decrease in the pipeline damage. The saturated soil undrained shear strength increases, while pipe damage increases. The established BP neural network prediction model for submarine pipe damage needs only six parameters, namely, falling object impact energy, pipe diameter, wall thickness, steel grade, internal pressure and undrained shear strength of seabed soil. It is simple and convenient, and can better predict the damage of submarine pipeline impacted by falling objects in saturated clay seabed. The numerical examples cover the working conditions of common saturated clay seabed submarine pipelines, so the model has good applicability, which provides new ideas for the prediction of submarine pipeline damage.