直埋敷设供热管道腐蚀失效概率仿真研究
Corrosion failure probability simulation of directly buried heating pipeline
摘要：
为了研究供热管道失效概率，根据直埋敷设供热管道的受力特点，基于广义的应力-强度干涉理论，建立了供热管道强度失效、垂直失稳、径向失稳和局部屈曲4种失效模式的极限状态方程。采用幂函数腐蚀模型研究了供热管道的腐蚀失效概率。根据影响因素的随机特性，应用蒙特卡洛方法仿真供热管道的受力状态，通过极限状态方程判断管道的安全、失效状态，统计失效概率。管径DN1000供热管道的仿真结果表明：强度失效是直埋敷设供热管道失效的主要模式；严重腐蚀环境下的管道失效概率增长速率呈现先快后慢的趋势；热水温度超过120 ℃时，管道失效概率陡增，平均增长速率可达到5.21×10-2 ℃-1。
Abstract：
To analyse failure probability of heating pipeline, according to the force analysis of directly buried heating pipeline, based on generalized stress-strength interference theory, establishes the limit state equations of four failure modes for pipeline which are strength failure, vertical instability, radial instability and local buckling.Studies the failure probability of heating pipeline caused by corrosion using power function corrosion rate model. According to the stochastic characteristics of the relevant factors, simulates the stress state of heating pipeline by the Monte Carlo method.Determines the safe and failure states of the pipeline by the limit state equation. Obtains the failure probability by dividing the total number of failure events with the total simulation times.The simulation results of DN1000 heating pipeline show that the strength failure is the main failure mode of the directly buried heating pipeline, the growth rate of pipeline failure probability accelerates at first and then slowdowns in severe corrosion environment, and when water temperature exceeds 120 ℃, the pipeline failure probability rises quickly and the average growth rate reaches 5.21×10-2/℃.
Keywords:heatingpipeline,directlyburied,corrosion,failureprobability,MonteCarlosimulation