基于衰减路径速度积的压力容器缺陷安全裕度及剩余寿命研究

The development of pressure vessels continues to focus on large-scale and complicated structure directions, especially the large complex pressure vessels used in areas of aerodynamic tests, nuclear power engineering, thermal power engineering, whose inherent defects are represented as congenital, acquired with variety and complexity. The inherent defects are concealed and emergent. These characteristics frequently lead to major accidents, therefore, research on the safety issue of pressure vessel defects has been the focus of attention in this field. .Nowadays, this project aims at the safety assessment of pressure vessel defects, the defect safety margin based on the double-criterion failure assessment ray method and its residual life estimation method cannot be flawed to reflect the time-varying problem of safety attenuation path and expansion rate. Aiming at the pressure vessel with defects in aerodynamic test, this paper analyzes the failure mechanism of the defect under the influence of fatigue stress and the extension of geometric dimension, and studies the main types of crack defects and the shape characteristics of safety attenuation path that affect the safety of equipment. This paper explores the time-varying relationship between the safety attenuation path and the failure rate, and then we raise the judgment theory of the failure point of the failure path loss failure path. Based on this theory, an algorithm model of the safety margins and the remaining lifetimes of the defect attenuation path and the failure rate time-variability are established. Therefore, based on the Product of Attenuation Path and Speed, the attenuation path velocity product, we propose a new method to evaluate the safety margins and predict the residual life of the flaw in the pressure vessel.

压力容器不断向大型化、复杂化方向发展，特别是应用于空气动力试验、核电工程、热电工程等大型复杂压力容器，其内含缺陷具有先天性与后发性、多样性与复杂性、隐蔽性与突现性等特点，由此引起的重大安全事故多发频发，因而针对压力容器缺陷安全程度的研究一直是该领域关注的重点。.本项目针对基于双判据失效评定图射线法、模糊函数隶属度法等传统方式对缺陷安全裕度及其剩余寿命估算不能反映缺陷安全衰减路径与扩展速率的时变性问题，面向空气动力试验等含缺陷压力容器，分析缺陷在疲劳应力作用及几何尺寸延展下的安全失效机理，研究主要影响设备安全的裂纹缺陷的各类安全衰减路径形态特征，探索缺陷安全衰减路径与失效速率间的时变关系，提出缺陷失衰减路径失效速率拐点的判定理论，建立反映缺陷衰减路径与失效速率时变性的安全裕度及其剩余寿命的算法模型，从而提出一种基于衰减路径速度积的压力容器缺陷安全裕度评价与剩余寿命预测的新方法。

本项目主要面向空气动力试验、核反应装置、石化工程、热电工程、深地原为取芯等大型复杂的含缺陷压力容器，针对基于双判据失效评定图射线法的缺陷安全裕度表征、传统剩余寿命预测不能反映缺陷安全衰减的时变性问题，首次提出了在役金属压力容器缺陷“安全衰减路径”的学术概念。基于这一概念，项目重点分析了压力容器各类裂纹缺陷的安全失效机理，研究了主要影响压力容器容管设备安全的各类裂纹缺陷的安全衰减路径形态特征，研究了在役压力容器裂纹缺陷安全衰减路径与失效扩展速率da/dN间的时变关系。基于缺陷衰减时变机理，提出了缺陷安全衰减路径等时效仿真的关联函数模型，建立了反映缺陷安全衰减时变性的安全裕度及剩余寿命的算法模型。项目围绕“安全衰减路径”学术方向取得的一系列成果，在压力容器缺陷安全研究领域形成了新的理论技术体系，为在役金属压力容器缺陷失效跟踪、安全裕度及剩余寿命预测提供了一种新的理论技术方法。.项目团队发表了8篇反映本项目研究成果的学术论文，申请了4项发明专利，其中3项获得授权，并获得两项软件著作权，完成项目的研究任务。