舰船含腐蚀缺陷通海管路失效压力数值分析

Numerical Analysis on Failure Pressure of Warship Seawater Pipelines with Corrosion Defects

关键词:  舰船通海管路  腐蚀缺陷  预测模型  数值分析  爆破失效  应变失效判据

Key words:  Warship seawater pipelines  Corrosion defects  Prediction model  Numerical analysis  Bursting failure  Strain failure criterion

摘要:

为研究舰船通海管路腐蚀后失效压力预测问题，在DNV RP-F101准则的基础上设置模型系数，建立了管路预测模型，并通过数值分析修正模型系数。使用Abaqus软件分析管道爆破失效力学行为，研究缺陷形貌和腐蚀深度、腐蚀轴向长度对失效压力的影响。对比预测模型与数值分析可知，模型系数为Y_FEA=1.034时，预测模型可以较好地预测通海管路失效压力。仿真结果表明：通海管路失效形式为爆裂失效；管道壁厚对失效压力存在影响但影响很小。对于具有相同深度和长度的缺陷类型，椭球型对管路强度影响最大，柱面型最小。对同种缺陷类型，以矩形平底缺陷为例，腐蚀深度对管道强度影响最大，与失效压力呈负线性；失效压力随腐蚀轴向长度增加呈指数形式下降，但腐蚀轴向长度超过一定值时，失效压力趋于稳定。

Abstract:

In order to study the failure pressure prediction of corroded warship seawater pipelines， based on DNV RP-F101 criterion， the pipeline prediction model was established through setting the model coefficient， and the coefficient was corrected by numerical approach. The mechanical behavior of pipe bursting was analyzed and the influence of defect morphology， corrosion depth and axial length on the failure pressure was studied by Abaqus. The comparison of the prediction model and finite element analysis （FEA） results show that when the model coefficient is Y_FEA=1.034， the prediction model can well predict the failure pressure of the seawater pipeline. The simulation results show that the failure form of seawater pipeline is burst failure， and the pipe wall thickness has little influence on the failure pressure. For the defects form with same depth and length， the ellipsoidal group has the greatest influence on the pipeline strength and the cylindrical has the least influence. For the same defect type， taking locally uniform defect as an example， corrosion depth has the greatest influence on pipeline strength and is negatively linear with failure pressure. The failure pressure decreases exponentially with the corrosion axial length increasing， and when the corrosion axial length exceeds a certain value， it tends to be stable.