考虑损伤的石油井架极限承载性能仿真研究

Study on Simulation for Ultimate Bearing Capacity of Oil-Derrick with Damage

针对石油井架的结构特点和存在的损伤形式,提出损伤指标函数的概念,推导了三种常见的损伤形式的损伤指标函数,构建井架结构损伤仿真计算模型。以此为基础,根据结构的梁柱效应以及大位移效应,应用集中塑性法,考虑几何非线性和材料非线性对石油井架极限承载能力的双重影响,建立了极限承载能力双重非线性数学仿真模型,提出了石油井架极限承载能力仿真评价体系。对某油田使用的井架进行仿真分析,结果表明:应用该方法可以确定井架的失稳状态、薄弱部位、安全乃至极限承载范围,并通过试验验证了该方法的可行性。为有损伤石油井架的安全评定及状态监测提供了有效的方法和依据,适合工程应用。

Aiming at structure feature and damage mode of oil-derrick,the concept of the damage function was described,the damage functions were deduced which reflected three modes of structure damage,consequent simulation models were established.Based on these,double nonlinear mathematical model was established in which double effects of geometric and material nonlinear to ultimate bearing capacity of oil-derrick were considered according to the effect of girder-column and large displacement and using the concentrated inelasticity approach.And simulation evaluation system for ultimate bearing capacity of oil-derrick was proposed.Simulation analysis was carried out for the derrick in-service of an oilfield.The results indicate that the failure shape,dangerous position,scope of safety and ultimate bearing capacity can be obtained.The feasibility of this method was verified throughout load experiment.This method provides an effective way for the safety evaluation and state monitoring of oil-derrick with damage,suitable for practical engineering applications.