Predictive maintenance and its applications in civil engineering structures:A review

Structural health monitoring and performance prediction are crucial for smart disaster mitigation and intelligent management of structures throughout their lifespan.Recent advancements in predictive maintenance strategies within the industrial manufacturing industry have inspired similar innovations in civil engineering,aiming to improve structural performance evaluation,damage diagnosis,and capacity prediction.This review delves into the framework of predictive maintenance and examines various existing solutions,focusing on critical areas such as data acquisition,condition monitoring,damage prognosis,and maintenance planning.Results from real-world applications of predictive maintenance in civil engineering,covering high-rise structures,deep foundation pits,and other infrastructure,are presented.The challenges of implementing predictive maintenance in civil engineering structures under current technology,such as model interpretability of data-driven methods and standards for predictive maintenance,are explored.Future research prospects within this area are also discussed.

Redundancy Measure and Its Application to the Design and Maintenance of Marine Structures

This paper is a survey of the state-of-the-art knowledge in structural redundancy measure and its application. The existing deterministic and probabilistic measures of structural redundancy are summarized. Emphasis is given to the discussion of their advantages and limitations. The application bf damage tolerance concept in the design and maintenance of marine structures is also reviewed. Some most critical problems in structural redundancy are proposed for future research.

Exploration on Defect Prevention and Maintenance Methods of Highway Tunnel Structure

Highway tunnel traffic safety is an important part of traffic safety.With the aging of tunnels,increase in traffic flow,changes in the operating environment and traffic accidents,the many problems started to occur in tunnels,affecting the operational and structural safety.In this paper,we summarize and analyze the types and causes of defects found in the process of tunnel maintenance at home and abroad,and propose corresponding suggestions for the current maintenance of the main structure of highway tunnels.

DELAY-TIME MODEL BASED ON IMPERFECT INSPECTION OF AIRCRAFT STRUCTURE WITHIN FINITE TIME SPAN

According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model.

基于ISM模型的航班进港错漏接诱因关系分析

随着中国民航的快速发展,为探索航班进港错漏接诱因的内在规律,保障航班正常运行,结合接机流程和专家访谈,得出11个错漏接诱因,构建解释结构模型,借助矩阵计算和图形分析技术,深度分析航班进港错漏接的致因关系,从接机人员和派工人员两个层面得出航班进港错漏接环节的逻辑关系,为解决民航航班进港错漏接的问题提供了参考。

Diagnostic Study on the Structural Characteristics of a Typical Mei-yu Front System and Its Maintenance Mechanism

In this paper, a typical mei-yu front process with heavy rainfall from June 12 to 15 in 1998 is analyzed. The results show that the mei-yu front is a front system which consists of an iso-theta(e) dense area with strong horizontal gradient, a deep-convective cloud tower band, a passageway transporting warm and moist air flow from the summer monsoon surge in the mid and low levels to the south of the mei-yu front, and a migrating synoptic scale trough to the north of the mei-yu front, which transports cold and dry air southward in the mid and upper levels. The maintenance of the mei-yu front is realized by: (1) is a positive feedback between the moist physical process enhancing frontogenesis and the development of the strong convective system in front of the mei-yu front; (2) the sustaining system to the north of the mei-yu front which is a migrating synoptic scale trough transporting cold and dry air to the mei-yu front and positive vorticity to the mesoscale system in front of the mei-yu front.

Opportunistic maintenance for multi-component systems considering structural dependence and economic dependence

Although opportunistic maintenance strategies are widely used for multi-component systems, all opportunistic mainte- nance strategies only consider economic dependence and do not take structural dependence into account. An opportunistic main- tenance strategy is presented for a multi-component system that considers both structural dependence and economic dependence. The cost relation and time relation among components based on structural dependence are developed. The maintenance strategy for each component of a multi-component system involves one of five maintenance actions, namely, no-maintenance, a minimal maintenance action, an imperfect maintenance action, a perfect maintenance action, and a replacement action. The maintenance action is determined by the virtual age of the component, the life expectancy of the component, and the age threshold values. Monte Carlo simulation is designed to obtain the optimal oppor- tunistic maintenance strategy of the system over its lifetime. The simulation result reveals that the minimum maintenance cost with a strategy that considers structural dependence is less than that with a strategy that does not consider structural dependence. The availability with a strategy that considers structural dependence is greater than that with a strategy that does not consider structural dependence under the same conditions.

Review on Artificial Intelligence-aided Life Extension Assessment of Offshore Wind Support Structures

The primary objective of the present literature review is to provide a constructive and systematical discussion based on the relevant development,unsolved issues,gaps,and misconceptions in the literature regarding the fields of study that are building blocks of artificial intelligence-aided life extension assessment for offshore wind turbine support structures.The present review aims to set up the needed guidelines to develop a multi-disciplinary framework for life extension management and certification of the support structures for offshore wind turbines using artificial intelligence.The main focus of the literature review centres around the intelligent risk-based life extension management of offshore wind turbine support structures.In this regard,big data analytics,advanced signal processing techniques,supervised and unsupervised machine learning methods are discussed within the structural health monitoring and condition-based maintenance planning,the development of digital twins.Furthermore,the present review discusses the critical failure mechanisms affecting the structural condition,such as high-cycle fatigue,low-cycle fatigue,fracture,ultimate strength,and corrosion,considering deterministic and probabilistic approaches.

Shock resistance of supercharged boilers through integration with ship structure

The non-linear finite element software ABAQUS was used to simulate the dynamic response of a marine supercharged boiler when subjected to impact loading. Shock resistance was analyzed by the time-domain simulation method. After exhaustive simulations,the effect of air pressure induced by different working conditions on the shock response of a supercharged boiler was reviewed,leading to conclusions about the variability of structural response with different loading parameters. In order to simulate the real impulsive environments of supercharged boilers,the integration of equipment and ship structure was then primarily used to analyze shock response. These distinctly different equipment shock test methods,run under equivalent work conditions,were compared and the causes of discrepancy were analyzed. The main purpose of this paper is to present references for the anti-shock design of marine supercharged boilers.

Bidirectional Clone Node Model of Optimizing Performance of Structured P2P Overlay Network

In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.

Factors Affecting Quality of Equipment Maintenance Based on Structural Equation Modeling

Factors affecting equipment maintenance quality usually include personnel,equipment and facilities,raw materials and spare parts, craft, environment and quality management. These six factors affecting maintenance quality are not all the same degree. In order to find out which factor can influence equipment maintenance quality greatly and achieve sophisticated management,characteristic quantities of six factors are presented. A structural equation modeling( SEM) is designed using the six factors as latent variables and their characteristic quantities as the observed variable.According to the basic data obtained from the questionnaire survey,calculate the standardized regression weight by parameter estimation of the SEM. Then the key factors affecting the quality of the equipment maintenance are determined with the help of the standardized regression weight.

The Markovian Approach for Probabilistic Life-Cycle Assessment of Existing Structures

The reliability of structural systems, lying in aggressive environments, changes over time. Proper maintenance is usually required to achieve a suitable performance level of life-cycle. The damage process affecting the systems often suffers from uncertainty due to the randomness involved in each environmental attack. Therefore, basing on suitable damage modeling as well as on probabilistic analysis, the main features of time-variant deterioration process are modeled and then the life-cycle is assessed. On the basis of Markov renewal theory (MRT), this paper proposes a combined approach using an appropriate time dependent damage model and probabilistic analysis. Since repairing deteriorated structures requires the arrangement of maintenance strategies, possible selective maintenance scenarios have to be considered. Referring to the relationship between MRT and an appropriate condition index, some repair strategies have been proposed and compared with each other. Those strategies are applied just to seriously deteriorated members. Furthermore selective maintenance benefits are economically investigated.

Maintenance Management Research of a Large-span Continuous Rigid Frame Bridge Based on Reliability Assessment by Using Strain Monitored Data

When the bridge components needing maintenance are the world problem at present,and the health monitoring system is considered to be a very help­ful tool for solving this problem.In this paper,a large number of strain data acquired from the structural health monitoring system(SHMS)installed on a continuous rigid frame bridge are adopted to do reliability assessment.Firstly,a calculation method of punctiform time-dependent reliability is proposed based on the basic reliability theory,and introduced how to cal­culate reliability of the bridge by using the stress data transformed from the strain data.Secondly,combined with“Three Sigma”principle and the basic pressure safety reserve requirement,the critical load effects distribu­tion function of the bridge is defined,and then the maintenance reliability threshold for controlling the unfavorable load state which appears in the early operation stage of this type bridge is suggested,and then the combi­nation of bridge maintenance management and health monitoring system is realized.Finally,the transformed stress distribution certifies that the load effects of concrete bridges practically have a normal distribution;as for the concrete continuous rigid frame bridge with C50 strength grade concrete,the retrofit reliability threshold should be valued at 6.13.The methodology suggested in this article can help bridge engineers do effective maintenance of bridges,which can effectively extend the service life of the bridge and bring better economic and social benefits.

Information-Body Relation and Information as a Solution of the Consciousness Problem in the Biological Structures

This paper approaches two main philosophical questions concerning the biological structures,from unicellular to multicellular organisms:one of them(i),referred to the information-body relation,as an extension of the mind-body relation at human,and another one(ii),to the consciousness problem,concerning the existence and nature of consciousness(if any),at the inferior organisms on the complexity scale,as this concept is known at humans.As philosophy benefits of the privilege to use data/concepts from other sciences to obtain philosophical conclusions,there were included detailed descriptions of some key biologic mechanisms,analyzed from informational perspective,necessary just to support/demonstrate/reinforce the informational nature/substrate of the mentioned relations.The analysis of the close relation between information and body,related to the structuration and functional properties of the biological organisms,from cells to multicellular structures,shows that all of them are able to“embody/disembody”information during/by structuration/destructuration processes of matter,in particular that of DNA/RNA/proteins,their functions appearing as a result of their informational capabilities to internally manage the inter-connection with environment,primarily due to their permanent dependence on the food resources and adaptation/survival needs.The experimental and theoretical studies,revealing/documenting on one hand the automatic management of maintenance metabolic processes,the reproduction,and growth/development,and on the other hand the adaptive decision-making/sentient processes as a responsive reaction to the environmental cues,show/support the consistency of the informational model of the human body and living structures on the entire biological scale,providing support to the informational solution of the stated problems(i)and(ii).A distinct attention is paid to plants,which are organisms without nervous system,but which show/manifest also informational capabilities to detect/react to information and to modulate their behavior accordingly.The question if the living organisms possess a pseudo/proto-consciousness level as a consequence of the informational activity of their body,distinct from human,but active in any biological structure under certain conditions is furthermore discussed,and a reliable definition of rudimentary pseudo/proto-consciousness level is given/described and compared with other empirical/theoretical concepts.

精表处在公路预防性养护中的应用研究

沥青路面长期暴露在自然条件下,受外界因素的影响,经常出现各种各样的病害,大部分病害都是逐渐形成的。因此,道路的预防性养护工作要得到足够重视,在病害早期阶段就加以控制。预防性养护就是在既有路面上加一个不超过4 cm的薄层,经过研究精表处可以提高沥青路面的防水性能、抗滑性能,对路面的平整度和行车舒适性也会有明显改善。该文以某省道为例,经过路况调查评价,使用精表处对预防性养护路段进行处理,精表处施工前后,渗水系数、摩擦系数、构造深度均有明显改善。精表处施工无需加热,对于资源节约、环境保护方面可以起到积极的作用,同时还具有养护成本低、质保时间长等优点。

钻爆法公路隧道防排水技术发展综述

为研究钻爆法公路隧道防排水技术的发展趋势和未来方向,系统梳理了防排水技术的发展历程、技术要求、设计施工和维护技术等内容,并对需要关注的问题及下一步发展方向进行展望。结果表明:按照隧道建设的技术发展水平,防排水技术可划分为圬工时代和后混凝土时代,已实现原则指导、设计优化、材料革新、施工控制、标准保障及运营维护的基本构架;中国在新修订的规范中增补了隧道渗漏水量化标准,使防水等级规定更具客观性、科学性;从防排水系统构造形式的对比情况看,控制排水型隧道能兼顾隧道衬砌水压力和维护隧道区生态平衡等多方面需求;钻爆法隧道防排水技术虽然增加了一些可维护性设计,但仍以功能性设计为主,且现有技术难以满足防排水系统的维护需求。应当注意:防排水技术是一个系统性问题,需要建立基于全寿命周期的建管养一体化防排水体系,并对防排水系统选型和控制型防排水技术进行系统性研究,通过对全寿命周期内隧道排水的环境影响进行分析评价,确定合理的防排水构造型式;另外,需加强防排水系统优化及新工艺研究,加快新型防排水材料的开发;同时要加强维护技术研究,尤其是可维护性技术和修复性技术研究。

强电场作用下早龄期混凝土的氯离子迁移特征

电化学除氯技术能有效降低混凝土结构中的有害氯离子,降低混凝土结构失效风险。采用强电场方式对混凝土结构进行电化学除氯,并在不同的早龄期时间介入40、80、120 min的强电场作用,测试了内部氯离子含量变化和分布特征,并对通电后养护28 d试件进行回弹强度试验。研究结果表明:早龄期介入强电场作用能显著提高除氯效率,达到相同除氯效果时的作业时间约为传统电化学方法的1/300;氯离子分布特征表明,自由氯离子分布较传统电化学参数作用时更均匀,结合氯离子仍然存在保护层中间堆积现象;强电场作用后进行标准养护,回弹测试结果表明,强电场对混凝土的保护层宏观强度无明显影响。

大连湾海底隧道结构健康监测系统研究与应用

结构健康监测是通过无损、实时的方式识别外部环境变化及结构自身变化,实现损伤识别、评估分析、安全预警等功能,从而快速辨别结构的健康状态的监测手段。结构健康监测系统可为项目的智慧管养、运维提供决策和支持,达到降低运营风险、延长结构使用寿命、节约运营成本的目的。文中从监测系统中监测内容的设计、监测平台的软硬件构建等方面对大连湾海底隧道结构健康监测系统进行介绍,应用反馈的监测数据验证了监测系统的准确有效性。

民用飞机预测维修技术研究进展

民机维修理论伴随航空科技进步在不断往前发展,从定时翻修到以可靠性为中心的计划维修,以及先进的视情与预测维修理念。现代民机测试性的发展,特别是系统/结构健康监测技术的发展和成熟,丰富了现有的持续适航概念和方法体系,在确保飞机满足持续适航要求的前提下,飞机由经验化的基于时间的计划维修向更加高效的基于系统/结构实际健康状态的维修转变。本文总结了民用飞机预测维修技术的最新研究进展情况,从以传统计划维修模式为基础引出预测维修模式,包括结构/系统预测维修任务分析方法、预测维修方案优化、预测维修关键技术以及在民机领域的应用情况。

RAS储层分析仪故障分析及维修对策

储层分析仪RAS在各大油田均有使用,主要用于剩余油评价,仅在长庆油田每年使用该仪器平均测井80口,测井井口数一直在增加,对仪器基本原理和各短节结构及功能进行介绍,给出一般故障现象及维修对策,并从发生的三起典型故障进行分析提供解决对策,旨在帮助维保该仪器的维修人员快速判断故障,提高维修时效。