冻土区双腐蚀管道失效机理的仿真模拟教学OA

[Objective]In view of the abstract nature of frozen soil-corrosion multi-field coupling theory in the course of civil engineering disaster prevention and mitigation,students often find it difficult to establish a systematic understanding of thermal-mechanical-corrosion co-evolution.Combined with the practical need to address the insufficient predictive accuracy of pipeline engineering failures in frozen soil areas,an experimental-simulation mutual verification teaching mode based on the failure mechanism of axially double-corroded pipelines is constructed.[Methods]Based on the ABAQUS platform,a fully coupled thermal-mechanical-corrosion numerical model was developed.Through parametric modeling using the Mohr-Coulomb model for frozen soil and the Ramberg-Osgood constitutive model for pipelines,students mastered the thermal-mechanical coupling at the frozen soil-pipeline interface.The model was verified using full-scale blasting test data,and students were guided to carry out an orthogonal experimental design to analyze the coupling effects of corrosion depth,length,and spacing.Based on dynamic visualization of stress cloud maps,students were guided to identify the stress-concentration law for deep asymmetric defects,and an independent quadratic polynomial failure pressure prediction model was constructed.[Results]Through orthogonal test design and stress cloud diagram analysis,students were guided to reveal the failure law of double-corroded pipelines in permafrost regions.Corrosion depth dominated the evolution of failure pressure.When the depth of double defects increased from 3.2 mm to 9.6 mm,the failure pressure decreased by 44.5%.When the corrosion length increased from 150 mm to 350 mm,the failure pressure decreased by only 14.3%.Stress concentration under asymmetric corrosion depth conditions was significantly greater in the deep defect area,while effective stress concentration still existed in the short defect under asymmetric corrosion length conditions,further strengthening engineering cognition of the priority of depth parameter control.Based on three-dimensional response surface analysis,students found that the spacing sensitivity of asymmetric corrosion was significantly weaker than that of symmetric combinations,and the failure pressure under the 6.4-6.4 mm combined corrosion spacing of 120 mm was 0.18 MPa higher than that under the 40 mm working condition.Students developed a quadratic polynomial failure pressure prediction model,and the average prediction error was significantly lower than the DNV standard.This process effectively cultivated students'ability to identify critical failure characteristics from stress distributions and to develop systematic deductive reasoning regarding the multi-field coupling disaster chain of thermal corrosion.[Conclusion]The"experiment-simulation mutual experience"mode constructed through teaching practice effectively connects frozen soil-corrosion multi-field coupling theory with the training pathway for engineering decision-making ability.By designing gradient simulation tasks and applying dynamic visualization tools,students can systematically master the co-evolution analysis method for the temperature,stress,and corrosion damage fields.Through three-dimensional response surface analysis,abstract multi-field coupling mechanisms are translated into engineering decision-making criteria that emphasize depth-first prevention and control.The failure pressure prediction model developed by students overcomes the limitations of traditional codes that insufficiently consider frozen soil coupling effects,provides a theoretical framework for pipeline disaster prevention teaching and engineering safety assessment in frozen soil areas,and enables an educational transformation from knowledge transfer to complex engineering problem-solving.