直埋供热管道小折角加固结构有限元模型的广义优化辨识方法研究
Research on generalized optimization identification method for finite element model of directly buried heating pipelines with small folded angle reinforcement structure
摘要：
有限元数值模拟是分析直埋管道折角受力特征和应力分布的主要方法,然而其模拟结果与实测数据的偏差通常较大,不能正确预测折角结构的最大应力值。本文聚焦直埋管道的小折角加固结构,系统分析了有限元数值模拟的误差来源,并提出了一种新型分阶段广义优化辨识的方法,依次确定折角加固结构的最优边界条件及关键模型参数。计算案例表明:模拟非均匀应力能够提供最佳的边界应力分布;管道与土壤的弹性模量为有限元模拟的关键参数;对于小折角加固结构(管径DN700、角度12°),管道与土壤的弹性模量最优取值分别为19.94×104MPa和11 MPa。
Abstract：
The finite element numerical simulation is the main method to analyse the mechanical characteristics and stress distribution of the folded angle of the directly buried pipelines. However, the deviation between its simulation results and measured data is usually large, and it cannot correctly predict the maximum stress value of the folded angle structure. This paper focuses on the small folded angle reinforcement structure of directly buried pipelines, systematically analyses the error sources of finite element numerical simulation, and proposes a new staged generalized optimization identification method to sequentially determine the optimal boundary conditions and key model parameters of the folded angle reinforcement structure. The calculation case shows that simulating non-uniform stress can provide the best boundary stress distribution. The elastic modulus of pipeline and soil is the key parameter for finite element simulation. For the small folded angle reinforcement structure (pipe diameter DN700, angle 12°), the optimal values of the elastic modulus of pipeline and soil are 19.94×104MPa and 11 MPa, respectively.
Keywords:directly buried heating pipeline; small folded angle; reinforcement structure; stress distribution; finite element numerical simulation; staged generalized optimization identification