Maintenance, Reliability and Condition Monitoring
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About long-term stability of functional treatment
Get PDFRelapse has always been the main problem in orthodontics. But is it due to the treatment method? Or the age of the patient or the anatomy of the skull? At the examples of some case histories, these questions are considered and hopefully, will contribute a bit to this eternally controversial subject
Fatigue performance analysis and reinforcement measures for foundation connection components of wind turbine towers
Get PDFIn recent years, frequent tower collapses have been mostly related to fatigue damage. Therefore, this paper systematically studies the fatigue resistance performance and reinforcement methods of tower foundation connection components through on-site tests and finite element analysis. The test analyzed the lifespan, stress-strain characteristics, crack development and mechanical properties of the connection components under fatigue loads; numerical simulation compared the fatigue life and safety of ordinary components, reinforced with steel mesh, C100 high-strength concrete components, and C40 and C100 composite components, etc., providing key basis for engineering reinforcement
Investigation of transient processes in auxiliary asynchronous electric motors of locomotives using differential equations
Get PDFThe aim of this research is to scientifically substantiate the operating conditions of small and medium-power auxiliary asynchronous electric motors currently in use on mainline electric locomotives of the VL60, VL80, and Ermak 3ES5K types. The goal is to draw conclusions based on scientific research, such as evaluating the operational efficiency of auxiliary asynchronous electric motors and creating the possibility to predict their service life based on the assessment results. This, in turn, will enable timely maintenance of auxiliary engines in locomotives
Theoretical assessment of the mechanical properties of fiber concrete using the dispersion analysis method
Get PDFThis paper examines how the type of fiber and the amount of fiber in concrete impacts the mechanical characteristics of fiber-reinforced concrete (FRC) by both experimental testing and statistical modelling. Basalt, polypropylene, and steel fiber reinforced concrete specimen were cast at different percent ratios (0, 0.1, 0.2 and 0.3) and subjected to laboratory conditions to measure compressive strength. At every dose and fiber type, three specimens were tested, and average values of the strengths were computed. OriginPro was used to fit the data in polynomial regression models (second degree) to quantify the connections between the parameters of this fiber and compressive strength. The most important statistical indicators provided in the assessment of the model accuracy were coefficients of determination (R2), adjusted R2, F-statistics, p-values, and residual analysis. The results revealed that the models were all characterized by high predictive accuracies (R2= 0.72, 0.93) and found to be significant using ANOVA (p< 0.0001). Results validated that the type of fiber along with the dosage were critical in the effectiveness of strength with optimal amount enhancing performance and loads beyond or below those levels decreasing the matrix bonding. The produced models offer a predictive predicting model that would be helpful in FRC mixture optimization. The study presents significant information in the field of structural engineering where a newly established structure will be needed to have superior durability, dependability, and load capacity
Magnetoelectrochemical theory of metabolism and life is a new trend in complexity in health sciences
Get PDFIn 2018, research was initiated to investigate the role of electromagnetic processes in human metabolism. This theoretical research is part of the research work of the Department of Internal Medicine and Emergency Medicine of Poltava State Medical University (23, Shevchenko St., 36011, Poltava, Ukraine) on “Development of algorithms and technologies for implementing a Healthy Lifestyle in patients with Non-Communicable Diseases (NCDs) based on the study of functional status” (state registration number 0121U108237: UDC 613 616-056-06: 616.1/9-03). The results of this work were embodied in the conceptualization of the Magnetoelectrochemical Theory of Metabolism and Life. The purpose of this article is to present to the academic community brief information about the results of the research work carried out in this direction for the further development of these scientific ideas and their integration into the scientific paradigm. Conclusions: 1) Magnetoelectrochemical Theory of Metabolism and Life is a new trend in Complexity in Health Sciences. 2) The biophysical direction of development of modern medicine opens up new ways to solve the problems of diseases of internal organs. 3) Knowledge of the fundamental aspects of electromagnetic communication of cells of the human body is a new basis for deepening the fundamental knowledge of the pathogenesis of diseases of internal organs, and this is a new promising direction for further research. 4) Bioelectronic Medicine, as a new component of medical science, is based on and directs therapeutic influence on the quantum levels of the structure and functioning of the human body. 5) The initiative educational and scientific project “Bioelectronic Medicine or Look at Medicine Differently” is a practical attempt in the conditions of the scientific present to find a way to change the scientific paradigm and popularize the latest knowledge among the academic community of the biomedical direction. 6) The practical application of this knowledge opens up new avenues for the further development of Magnetobiology, Internal Medicine, Microbiology, and Traditional Medicine. It can ensure progress in the treatment of diseases of internal organs, whether infectious or non-infectious in origin
Pattern recognition of acoustic emission signals by Q235 steel corrosion in marine environment
Get PDFTo overcome the limitations of traditional monitoring methods, which are restricted to periodic inspections, this study proposes a real-time method for identifying metal corrosion damage patterns to monitor the condition of Q235 steel corrosion based on acoustic emission (AE). Firstly, AE technology was utilized to monitor the corrosion process of Q235 steel plates in simulated industrial marine environment in real-time. Wavelet packet energy spectrum coefficients, closely related to the damage mechanism, were extracted from the acquired signals. A feature matrix was then constructed using principal component analysis (PCA) to eliminate redundant information and enhance computational efficiency. The K-means clustering algorithm was then applied to classify the AE signals into three classifications: the signals of mode 1 correspond to bubble rupture, the signals of mode 2 to pit growth and expansion, and the signals of mode 3 to the detachment of corrosion products and oxide film rupture. A damage pattern recognition model based on a convolutional neural network (CNN) was developed, enabling the real-time recognition of other unknown AE signals generating during the corrosion process of Q235 steel, and it exhibited satisfactory performance in accurately identifying corrosion-related acoustic emission patterns
Lightweight design of double-head machine tool beam based on the adaptive multi-objective method
Get PDFDouble-head machine tool has the advantages of high efficiency and high degree of automation. In order to reduce the weight of double-head machine tool and improve the stiffness of the entire machine. An optimization design method combining topology optimization, sensitivity analysis and adaptive multi-objective method is used. Firstly, simplify the model in SolidWorks and import it into ANSYS Workbench software to carry out finite element analysis on the entire double-head machine tool to find out the weak component as the beam. Afterwards, carry out topological optimization on the beam and redesign the beam structure, and complete the first optimization. Then, through sensitivity analysis of the input parameters, key parameters that significantly impact the objective function are identified. Subsequently, a multi-objective optimization function is constructed for these key parameters and the objective function. Finally, an adaptive multi-objective method is used to solve the problem and obtain a Pareto optimal solution set, completing the second optimization. The results show that the weight of the beam is reduced by 8.88 %, the deformation of the beam is reduced by 11.29 %, and the equivalent stress of the entire machine is reduced by 28.33 %. This design not only yields significant economic benefits but also serves as a valuable reference for the lightweight design of large machine tool crossbeams
Erratum: Bispectrum analysis based on dual channel homologous information fusion and its application in fault diagnosis
Get PDFThe properties of self-compacting fine-grained concrete mixtures for energy-efficient vibration-free construction technologies
Get PDFThe article presents the results of the development and research of self-compacting fine-grained concrete mixes for energy-efficient vibration-free construction technologies. The main focus is on selecting optimal compositions that ensure the required level of mobility and self-compaction through a rational ratio of components and the use of complex modifying additives. The results of research into the rheological characteristics of concrete mixtures, as well as the physical and mechanical parameters of the materials obtained, are presented. The patterns of the influence of the composition and structure of concrete on its density, strength, water absorption and deformability have been established. The results obtained confirm the possibility of creating effective self-compacting fine-grained concretes with high structural homogeneity and reduced energy consumption during production and laying
Multi-stage quantitative risk assessment of a critical system in mining industry
Get PDFEngineering Asset Management (EAM) is a strategic approach focused on the optimal management of physical assets throughout their lifecycle. By integrating engineering principles with financial and operational strategies, EAM aims to enhance asset performance, reliability, and longevity while minimizing risks and costs. This holistic methodology ensures that machinery, equipment, and infrastructure operate efficiently, thereby reducing failures and maximizing productivity. A critical component of EAM is understanding the criticality of each asset within a system. Criticality analysis evaluates the potential impact of different failure modes, considering factors such as failure likelihood, consequences, system interdependencies, cost implications, and associated risks. This analysis is essential for prioritizing maintenance efforts and allocating resources effectively. Risk assessment plays a pivotal role in this context, involving the systematic identification, analysis, evaluation, and management of potential risks associated with asset failures. However, traditional risk assessment methods often face challenges due to subjectivity and variability in evaluations, which can lead to inconsistencies in maintenance decision-making. To address these challenges, this paper proposes a novel multi-stage quantitative Failure Modes, Effects, and Criticality Analysis (FMECA) framework. This approach systematically analyses failure rates, downtime, and cost implications, providing a comprehensive understanding of each failure mode's impact. By integrating these quantitative parameters, the framework enhances objectivity in risk assessment and supports more informed decision-making. It enables organisations to systematically prioritize maintenance activities and optimize resource allocation. This approach not only mitigates operational risks but also aligns asset management practices with overarching business objectives, leading to improved efficiency and reduced costs. The proposed methodology is particularly beneficial in industries such as mining, manufacturing, and aerospace, where unplanned downtime and maintenance costs can have significant operational and financial repercussions. By adopting this multi-dimensional approach, organizations can improve asset performance, enhance safety, and achieve more sustainable operations