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.

Performance Characterization of CR/PU Asphalt for Potential Application in Assembled Fast-Repairing Engineering

Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.

Impact of Safety-Maintenance Practices on the Overall Performance of an Industry

The study aims to evaluate how safety-maintenance practices affect the mechanical engineering industry’s overall performance in Ghana. The study used a descriptive survey design technique to ascertain the type of maintenance engineering that was practiced in Ghanaian mechanical engineering workshops at the time of the study. In the mechanical engineering workshops, respondents provided both qualitative and quantitative data using a variety of data collecting instruments, with the quantitative approach being more common. The study employed Kumasi, Tamale, and Accra’s mechanical engineering workshops as a case study. The number of mechanical engineering workshop enterprises that made up the sample size for the questionnaire administration was sixty (60), chosen at random from the AGI membership registry. Primary data was gathered using interview guides and questionnaires. To analyse the data, descriptive statistics were employed. According to the study’s findings, mechanical engineering companies combined different maintenance techniques in order to best fit their organisational culture and equipment. Preventive shut-down, with a mean score of 4.78 and RII = 0.98, placing first (1st) in the Likert rating order, is the most frequently used maintenance system by respondents. The maintenance procedures employed by mechanical engineering organisations were influenced not only by their equipment and organisational culture but also by other factors such as cost, personnel expertise and external partnerships.

Study on Fracture Delay of High-Strength Bolts in Road Bridge Maintenance

In the maintenance work of highway and bridge engineering structures,the fracture delay of high-strength bolts is a content that needs to be focused on and researched.Based on this,the paper analyzes the fracture delay of high-strength bolts in highway bridge maintenance,including an overview of the fundamental research on fracture delay and related specific studies.It is hoped that this study can provide scientific reference for the reasonable maintenance of high-strength bolts,so as to ensure the overall maintenance effect of highway bridge projects.

Application Strategy of Digital Comprehensive Management and Maintenance System for Bridges

Effective application of digital integrated management and maintenance systems is essential for successful operation and maintenance management of bridge projects.This article analyzes the application strategy of such systems.It provides an overview of comprehensive digital management and maintenance of bridges,an analysis of the basic components of the integrated management and maintenance system,and its application strategies.This study aims to offer guidance for the application of the system and to improve the quality of modern bridge engineering management and maintenance work.

Dynamic Evaluation Model and Application Methods for Engineering Machine Maintenance Quality

It is an important content of equipment management to keep the engineering machine well. Based on the theory of component technology and grey related algorithm arithmetic, the requirements and procedures of engineering machine maintenance predicting process are analyzed, and a support object evaluation system is provided. The qualitative and quantitative indexes of evaluating process are fully taken into consideration to provide scientific methods and ways for proper evaluation and decision.

A Systemic Approach to Integrated E-maintenance of Large Engineering Plants

Large engineering plants （LEPs） have certain unique features that necessitate a maintenance strategy that is a combination of both time and condition based maintenance. Although this requirement is appreciated to varying degrees by asset owners, applied research leading to a systematic development of such a maintenance strategy is the need of the day. Such a strategy should also adopt a wholesome ＂systemic＂ approach so that the realization of the overall objectives of maintenance is maximized. E-maintenance has several potential benefits for large engineering plants. In this paper, a three pronged strategy is suggested for the successful implementation of e-maintenance for LEPs. Firstly, an integrated condition and time based maintenance framework is proposed for LEPs. Secondly, reference is drawn to models for condition and time based maintenance at systemic levels. As a part of the ab initio development of a condition monitoring system for a LEP, one of the characteristics of the condition monitoring system, namely, predictability, is discussed in detail as a sample for a systemic study. Thirdly, emphasis is laid on the information and expertise available in the domain of plant design, operation and maintenance and the same is tapped for incorporation in maintenance decision making.

Application of On-Line Rail Milling in Rail Maintenance of High-Speed Railways

On-line rail milling technologies have been applied in rail maintenance, and are proving to be efficient and environmental friendly. Based on the field data of on-line rail milling, a program for comparing rail transverse profiles before and after milling was designed and the root mean square （RMS） amplitude of longitudinal profile was calculated. The application of on-line rail milling technology in removing rail surface defects, re-profiling railhead transverse profiles, smoothing longitudinal profiles and improving welding joint irregularity were analyzed. The results showed that the on-line rail milling technology can remove the surface defects at the rail crown and gauge comer perfectly, re-profile railhead transverse profile with a tolerance of - 1. 0-0.2 ram, improve longitudinal irregularity of rail surface, with the RMS amplitude of irregularity reduced more than 50% and the number of out-of- limited amplitude reduced by 42% - 82% in all wavelength ranges. The improvement of welding joint irregularity depends on the amount of metal removal determined by the milling equipment and the primal amplitude.

Maintenance Engineering Department of China Eastern Jiangxi Branch Establishing the First Line of Defense for Safe Flight

Maintenance Engineering Department of China Eastern Jiangxi Branch has 130 employees and manages four Airbuses A319 and two A320s. seen from the ratio of man to plane, it is the lowest among China Eastern branches (subsidiaries). Due to the requirement of the air market, the six planes are arranged separately in Nanchang, Shanghai, Fuzhou and Ningbo, thus the six planes are maintained in four places, which is unique among China

CONDITION-BASED MAINTENANCE DECISION MAKING METHODS FOR CIVIL AEROENGINE

To provide some feasible condition-based maintenance （CBM） decision making methods for civil aeroengine, firstly, the theory of aeroengine CBM decision making is described. The proportional intensity（PI） model is established based on the reliability and condition monitoring data. According to the model, the decision making methods are proposed for the optimal preventive maintenance（PM） interval and removal. Then, the time on wing （TOW） is predicted by collecting actual data based on the engine age and operating conditions. Finally, an example of a fleet for CF6-80C2 engines is illustrated. It shows that sufficient engine operation data are the key of accurate decision making. Results indicate that the CBM decision making methods are helpful for engineers in airlines to control engine maintenance actions and TOW, thus decreasing risks and maintenance costs.

Development of Optimal Maintenance Policies for Offshore Wind Turbine Gearboxes Based on the Non-homogeneous Continuous-Time Markov Process

Gearbox in offshore wind turbines is a component with the highest failure rates during operation. Analysis of gearbox repair policy that includes economic considerations is important for the effective operation of offshore wind farms. From their initial perfect working states, gearboxes degrade with time, which leads to decreased working efficiency. Thus, offshore wind turbine gearboxes can be considered to be multi-state systems with the various levels of productivity for different working states. To efficiently compute the time-dependent distribution of this multi-state system and analyze its reliability, application of the nonhomogeneous continuous-time Markov process(NHCTMP) is appropriate for this type of object. To determine the relationship between operation time and maintenance cost, many factors must be taken into account, including maintenance processes and vessel requirements. Finally, an optimal repair policy can be formulated based on this relationship.

New technologies for high-risk tunnel construction in GuiyangGuangzhou high-speed railway

Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- tion was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technol- ogy was proposed and used in the field, which received a good air quality. Finally, a method to minimize the dis- tance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future.

Review on Application of Artificial Intelligence in Civil Engineering

In last few years,big data and deep learning technologies have been successfully applied in various fields of civil engineering with the great progress of machine learning techniques.However,until now,there has been no comprehensive review on its applications in civil engineering.To fill this gap,this paper reviews the application and development of artificial intelligence in civil engineering in recent years,including intelligent algorithms,big data and deep learning.Through the work of this paper,the research direction and difficulties of artificial intelligence in civil engineering for the past few years can be known.It is shown that the studies of artificial intelligence in civil engineering mainly focus on structural maintenance and management,and the design optimization.

Discussion on Management Model of Medical Equipment Maintenance in Hospital

With the development of technology, medical equipment plays a more important role in the modern hospital. Medical equipment provides images, physiological results or other schematics of the patients to help doctors deal with the routines. It is also the major tool to the lab assistant in the clinical teaching and studies. It becomes one of a symbol of the technological level in modern hospital. The director of the hospital should establish an effi cacious management pattern to manage the medical equipment, so that it will be operated in good condition to insure the safety of the patients. Since the maintenance is an important part of medical equipment management, it is significant that the hospital should establish a system to fit for itself. The study reviews the issues in hospital medical equipment maintenance management, the development of the maintenance management model and the characteristics, as well as the status at home and abroad. The research has been fi nished by using literature research method, questionnaire survey method and data analysis method. Then we analyze the current status of hospital medical equipment maintenance management model to fi nd the problems. Based on the authentic and effective data from the survey, we can deduce the overview about the maintenance model in Beijing. The paper discusses the advantages and the disadvantages between the different model, and it makes suggestions on the follow aspects, such as system management, quality management, personnel management, cost management, information management perspective.

A Comparative Study of Managing a Project Using Traditional Management Techniques and a Critical Chain Project Management Methodology in Aircraft Maintenance Field

Aircraft on ground or down-time for its maintenance is a clear loss in revenue for an airline operation. With never ending competition and growing operating costs of aircraft, airlines continuously need to explore opportunities to reduce the aircraft down-time in order to remain sustainable. Due to round the clock operation feature of scheduled airlines, aircraft maintenance operations are generally carried out using traditional management methodologies instead of considering it as a project. Though aircraft heavy maintenance checks consist of several major tasks that can last from few weeks to a year, the maintenance organisations do not adopt modern project management methodologies. Therefore, this paper models a heavy maintenance check of an Airbus aircraft as a typical project and adopts contemporary project management methodology to explore the possibility of reducing the downtime. To this end, a case study has been done at an aircraft maintenance company to analyse the potential of this project management method in aircraft maintenance industry.

Machinery and Equipment Maintenance Strategy and Choice

The advantages, disadvantages and characteristics of various maintenance strategies for modern mechanical equipment are analyzed. Combined with the system structure and functional characteristics of engineering equipment,it puts forward the selection method of maintenance strategies for different types of equipment and failure modes. The view of this article is that the comprehensive maintenance strategy, which is based on condition based maintenance(CBM) and combines various maintenance strategies. This will become the main development direction of engineering equipment maintenance.

人工智能在土木工程领域的应用研究现状及展望

作为新一代产业变革的核心驱动力,人工智能是全面提高土木工程领域数字化、自动化、信息化和智能化的重要方法。为全面了解人工智能在土木工程中的发展及应用,定性分析了人工智能的基本研究领域,定量分析了人工智能在土木工程设计、制造、养维护阶段的研究现状,利用CiteSpace可视化工具深入挖掘人工智能在土木工程中存在的问题、发展瓶颈和研究趋势,并给出相应的解决办法及研究思路。通过文献综述发现,土木工程领域已展开了大量人工智能研究,但各阶段智能化发展不均衡,实际应用也存在一定局限性,需深入探索神经网络、大数据、深度学习等智能技术在土木工程全生命周期的交叉融合,促进土木工程领域人工智能研究的协同发展。

基于三级养护标准的沥青路面预养护方案多目标加权灰靶决策

针对沥青路面最佳预防性养护策略选择问题,结合关于沥青路面预防性养护指标及规范标准,建立了基于判断性指标、综合性指标和控制性指标的三级预防性养护判断标准。在此标准下,以多年度项目级养护规划为研究对象,结合GM(1,1)预测模型确定预防性养护时段,并引入多目标智能加权灰靶决策模型对适用性预防性养护方案进行优化决策。在此过程中,确定了养护费用、耐久性等8个养护目标并利用博弈论组合赋权法确定权重,选取G30连霍高速甘肃省境内某路段进行决策分析。结果表明:该路段最早需要开展预防性养护的时间为第3年,在第6年底之后不宜再实施预防性养护,在该预防性养护时段内,方案4的综合效益值最大,其值为0.735 8,即应在第4年采取超薄层罩面预养护措施。该方法简单实用,可成为沥青路面预防性养护策略选择的一种新方法。

考虑资源稀缺性的路面养护措施综合效益全寿命周期费用评估

为提高道路工程中不可再生资源利用的合理性,建立养护措施综合效益的全寿命周期费用评价方法,推动交通运输基础设施的可持续发展,基于全寿命周期费用评价(life-cycle cost assessment,LCCA)理论,引入了资源稀缺性的评价指标,并基于存量稀缺、进口稀缺和技术稀缺3个评价维度,建立了适用于路用材料的项目级资源稀缺性评价体系,同时,将该指标量化为货币当量计入成本清单中。依托江苏省路面养护管理系统数据,将资源稀缺性、经济效益、性能发展3个维度统一,定量分析了再生类、铣刨重铺类和罩面类共3类、12个常见养护措施的综合效益。研究结果表明:考虑资源稀缺性,再生类养护措施旧料利用率较高,具有极佳的资源合理性;EC A-10薄层罩面处治厚度薄、耗材量小,与普通罩面相比能节省50%左右的资源;铣刨料直接废弃、石料来源选择不当将导致额外支出10%~20%的当量成本。考虑综合效益,各养护方案与施工特性(如施工工期、施工水平、工艺先进性等)相关的成本效益接近60%,其中用户间接的经济损失占比超过30%,直接由施工工期决定。因此,建议谨慎选择材料来源及去向以减少不可再生资源浪费,优化养护施工流程以降低用户的间接经济损失,提高施工水平以降低用户的直接油耗开支,开展科学养护决策以降低政府投入成本。

汽车发动机冷却系统故障诊断及维修关键技术探索

文章首先阐述了汽车发动机冷却系统的概念,介绍了该系统的设计原理及工作特点,在此基础上总结了系统故障成因,综合分析了导致冷却系统故障的各种因素及其具体表现,针对这些情况,提出针对性的诊断和维修关键技术。这不仅能显著提升发动机的功率和效率,还能降低系统故障率,提高车辆的可靠性,同时实现安全、节能和延长发动机寿命的目标。