It remains an important challenge to quantitatively describe the corrosion of reinforced concrete (RC) structures under chloride penetration. When considering the uncertainties encountered throughout the life cycle of RC structures exposed to a corrosive environment and evaluating their safety and reliability, the complexity of the problem intensifies. To address these issues, this paper focuses on the time-dependent reliability analysis of corroded RC beams, utilizing the phase-type (PH) fitting method. Initially, a model for the time-dependent reliability of corroded RC beams is established, incorporating the time-dependent chloride diffusion coefficient. Subsequently, a novel PH fitting method is proposed. The effectiveness of this new method is demonstrated through numerical examples. Furthermore, the time-dependent reliability analysis of corroded RC beams is compared using both the PH fitting method and the Monte Carlo simulation. The results reveal that the proposed method can accurately and efficiently deal with time-dependent reliability problems.
{"title":"Time-dependent reliability analysis of corroded RC beams based on the phase-type fitting method","authors":"Junxiang Li, Jianqiao Chen, Xinxin Zhang, Zijun Wu","doi":"10.17531/ein/172442","DOIUrl":"https://doi.org/10.17531/ein/172442","url":null,"abstract":"It remains an important challenge to quantitatively describe the corrosion of reinforced concrete (RC) structures under chloride penetration. When considering the uncertainties encountered throughout the life cycle of RC structures exposed to a corrosive environment and evaluating their safety and reliability, the complexity of the problem intensifies. To address these issues, this paper focuses on the time-dependent reliability analysis of corroded RC beams, utilizing the phase-type (PH) fitting method. Initially, a model for the time-dependent reliability of corroded RC beams is established, incorporating the time-dependent chloride diffusion coefficient. Subsequently, a novel PH fitting method is proposed. The effectiveness of this new method is demonstrated through numerical examples. Furthermore, the time-dependent reliability analysis of corroded RC beams is compared using both the PH fitting method and the Monte Carlo simulation. The results reveal that the proposed method can accurately and efficiently deal with time-dependent reliability problems.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"218 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135150827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Efficient fuel injection and exhaust gas cleaning systems are needed to promote the development of high-performance internal combustion systems and decrease greenhouse gas emissions. Electronically controlled injection systems enable nearly unlimited control over system components whose operation is limited by the inertia of moving parts and other physical phenomena. In the present study, a novel technology for manufacturing magnetic cores was proposed to improve the performance of solenoid injectors in Diesel engines. The conducted simulations and experiments revealed that the developed technology can increase the speed of solenoid injectors. In the proposed solution, the fuel dose was split to effectively control the injection process and improve engine performance.
{"title":"Analysis of potential improvements in the performance of solenoid injectors in diesel engines","authors":"Oleksandr Vrublevskyi, Sławomir Wierzbicki","doi":"10.17531/ein/166493","DOIUrl":"https://doi.org/10.17531/ein/166493","url":null,"abstract":"Efficient fuel injection and exhaust gas cleaning systems are needed to promote the development of high-performance internal combustion systems and decrease greenhouse gas emissions. Electronically controlled injection systems enable nearly unlimited control over system components whose operation is limited by the inertia of moving parts and other physical phenomena. In the present study, a novel technology for manufacturing magnetic cores was proposed to improve the performance of solenoid injectors in Diesel engines. The conducted simulations and experiments revealed that the developed technology can increase the speed of solenoid injectors. In the proposed solution, the fuel dose was split to effectively control the injection process and improve engine performance.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135404973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper depicts an application of Response Surface Methodology (RSM) for predicting selected parameters in turning of Ti-6Al-4V titanium alloy using polycrystalline diamond tool. Response surface plots that are generated by the model helps in determining the optimum combination of input factors (cutting speed vc and feed rate f) for best possible surface roughness (Sa), cutting force (Fc)and temperature (T) for dry and cooling turning. The methodology of multi-criteria optimization was used to establish the interaction between input parameters and given responses
{"title":"Multi-criteria optimization of the turning parameters of Ti-6Al-4V titanium alloy using the Response Surface Methodology","authors":"R. Kluz, W. Habrat, M. Bucior, K. Krupa, J. Sȩp","doi":"10.17531/ein.2022.4.7","DOIUrl":"https://doi.org/10.17531/ein.2022.4.7","url":null,"abstract":"The paper depicts an application of Response Surface Methodology (RSM) for predicting selected parameters in turning of Ti-6Al-4V titanium alloy using polycrystalline diamond tool. Response surface plots that are generated by the model helps in determining the optimum combination of input factors (cutting speed vc and feed rate f) for best possible surface roughness (Sa), cutting force (Fc)and temperature (T) for dry and cooling turning. The methodology of multi-criteria optimization was used to establish the interaction between input parameters and given responses","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"91 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84027938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main goal of the research presented in the article is to assess the impact of the destruction (degradation) of epoxy coatings, caused by the influence of a 25% aqueous solution of sodium chloride (brine), on the operational properties that determine the coatings reliability (durability). Samples of two-layer epoxy coatings (obtained from powder paints) were aged by immersing them in brine for a maximum period of 1680 h. The following criteria were used to assess the operational properties of the coatings: thickness, roughness and surface morphology, hardness, water absorption (mass increase), surface free energy. The FTIR and DSC tests performed showed a progressive development of the oxidation processes of the epoxy with the ageing period. The long-term impact of the brine resulted in the destruction of the coatings in the form of: craters, grooves, microcracks, including silver cracks. The contact of the coatings with brine also increased their: surface roughness (Ra, Rz, Rmax), thickness, mass, surface free energy, and decreased hardness and heat resistance.
{"title":"Influence of aqueous sodium chloride solutions on operational properties of epoxy coatings","authors":"D. Kotnarowska, Aleksandra Żabińska","doi":"10.17531/ein.2022.4.4","DOIUrl":"https://doi.org/10.17531/ein.2022.4.4","url":null,"abstract":"The main goal of the research presented in the article is to assess the impact of the destruction (degradation) of epoxy coatings, caused by the influence of a 25% aqueous solution of sodium chloride (brine), on the operational properties that determine the coatings reliability (durability). Samples of two-layer epoxy coatings (obtained from powder paints) were aged by immersing them in brine for a maximum period of 1680 h. The following criteria were used to assess the operational properties of the coatings: thickness, roughness and surface morphology, hardness, water absorption (mass increase), surface free energy. The FTIR and DSC tests performed showed a progressive development of the oxidation processes of the epoxy with the ageing period. The long-term impact of the brine resulted in the destruction of the coatings in the form of: craters, grooves, microcracks, including silver cracks. The contact of the coatings with brine also increased their: surface roughness (Ra, Rz, Rmax), thickness, mass, surface free energy, and decreased hardness and heat resistance.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"18 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82903242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The subject of the studies is the evaluation of the operation of a production system after modernization. The analysed case concerns the modernization forced by the end of the product lifetime. The proposed methodology is that of a multicriterial evaluation of the system operation after modernization. The evaluation criteria are selected TPM indices: availability of machinery and equipment, production process capacity, product quality and overall equipment effectiveness (OEE). The additional criteria are reliability indices MTBF and MTTR of studied production lines and the MTTR of the most unreliable equipment in each analysed line. A yearly monitoring of production process was proposed for obtaining the statistical credibility of the evaluation results. Additionally, a fuzzy indicator of acceptability of the modernization assessment was proposed. The paper presents the results of studies of the system for production of zinc concentrate from post-production waste. The obtained values of OEE, MTBF and MTTR indicators for the three tested lines make it possible to state that the modernization carried out is acceptable.
{"title":"Assessment of the modernized production system through selected TPM method indicators","authors":"E. Michlowicz","doi":"10.17531/ein.2022.4.8","DOIUrl":"https://doi.org/10.17531/ein.2022.4.8","url":null,"abstract":"The subject of the studies is the evaluation of the operation of a production system after modernization. The analysed case concerns the modernization forced by the end of the product lifetime. The proposed methodology is that of a multicriterial evaluation of the system operation after modernization. The evaluation criteria are selected TPM indices: availability of machinery and equipment, production process capacity, product quality and overall equipment effectiveness (OEE). The additional criteria are reliability indices MTBF and MTTR of studied production lines and the MTTR of the most unreliable equipment in each analysed line. A yearly monitoring of production process was proposed for obtaining the statistical credibility of the evaluation results. Additionally, a fuzzy indicator of acceptability of the modernization assessment was proposed. The paper presents the results of studies of the system for production of zinc concentrate from post-production waste. The obtained values of OEE, MTBF and MTTR indicators for the three tested lines make it possible to state that the modernization carried out is acceptable.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"44 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85084340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For mitigating and managing risk failures due to Internet of Things (IoT) attacks, many Machine Learning (ML) and Deep Learning (DL) solutions have been used to detect attacks but mostly suffer from the problem of high dimensionality. The problem is even more acute for resource starved IoT nodes to work with high dimension data. Motivated by this problem, in the present work a priority based Gray Wolf Optimizer is proposed for effectively reducing the input feature vector of the dataset. At each iteration all the wolves leverage the relative importance of their leader wolves’ position vector for updating their own positions. Also, a new inclusive fitness function is hereby proposed which incorporates all the important quality metrics along with the accuracy measure. In a first, SVM is used to initialize the proposed PrGWO population and kNN is used as the fitness wrapper technique. The proposed approach is tested on NSL-KDD, DS2OS and BoTIoT datasets and the best accuracies are found to be 99.60%, 99.71% and 99.97% with number of features as 12,6 and 9 respectively which are better than most of the existing algorithms.
{"title":"Double Layered Priority based Gray Wolf Algorithm (PrGWO-SK) for safety management in IoT network through anomaly detection","authors":"Akhileshwar Prasad Agrawal, Nanhay Singh","doi":"10.17531/ein.2022.4.5","DOIUrl":"https://doi.org/10.17531/ein.2022.4.5","url":null,"abstract":"For mitigating and managing risk failures due to Internet of Things (IoT) attacks, many Machine Learning (ML) and Deep Learning (DL) solutions have been used to detect attacks but mostly suffer from the problem of high dimensionality. The problem is even more acute for resource starved IoT nodes to work with high dimension data. Motivated by this problem, in the present work a priority based Gray Wolf Optimizer is proposed for effectively reducing the input feature vector of the dataset. At each iteration all the wolves leverage the relative importance of their leader wolves’ position vector for updating their own positions. Also, a new inclusive fitness function is hereby proposed which incorporates all the important quality metrics along with the accuracy measure. In a first, SVM is used to initialize the proposed PrGWO population and kNN is used as the fitness wrapper technique. The proposed approach is tested on NSL-KDD, DS2OS and BoTIoT datasets and the best accuracies are found to be 99.60%, 99.71% and 99.97% with number of features as 12,6 and 9 respectively which are better than most of the existing algorithms.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"8 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82396205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The low-pressure heat treatment of metals enables the continuous improvement of the mechanical and plastic properties of products, such as hardness, abrasion resistance, etc. A significant problem related to the operation of vacuum furnaces for heat treatment is that they become unsealed during operation, resulting from the degradation of seals or the thermal expansion of the construction materials. Therefore, research was undertaken to develop a prediction model for detecting leaks in vacuum furnaces, the use of which will reduce the risk of degradation in the charge being processed. Unique experimental studies were carried out to detect leakages in a vacuum pit furnace, simulated using the ENV 116 reference slot. As a consequence, a prediction model for the detection of leaks in vacuum furnaces- which are used in the heat treatment of metals- was designed, using an artificial neural network. (93% for MLP 15-10-1) was developed. The model was implemented in a predictive maintenance system, in a real production company, as an element in the monitoring of the operation of vacuum furnaces.
{"title":"Analysis and prediction of leak detection in the low-pressure heat treatment of metal equipment","authors":"S. Klos, J. Patalas-Maliszewska, M. Bazel","doi":"10.17531/ein.2022.4.12","DOIUrl":"https://doi.org/10.17531/ein.2022.4.12","url":null,"abstract":"The low-pressure heat treatment of metals enables the continuous improvement of the mechanical and plastic properties of products, such as hardness, abrasion resistance, etc. A significant problem related to the operation of vacuum furnaces for heat treatment is that they become unsealed during operation, resulting from the degradation of seals or the thermal expansion of the construction materials. Therefore, research was undertaken to develop a prediction model for detecting leaks in vacuum furnaces, the use of which will reduce the risk of degradation in the charge being processed. Unique experimental studies were carried out to detect leakages in a vacuum pit furnace, simulated using the ENV 116 reference slot. As a consequence, a prediction model for the detection of leaks in vacuum furnaces- which are used in the heat treatment of metals- was designed, using an artificial neural network. (93% for MLP 15-10-1) was developed. The model was implemented in a predictive maintenance system, in a real production company, as an element in the monitoring of the operation of vacuum furnaces.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"598 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77623646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Kosiba, Z. Tkáč, J. Jablonicky, V. Shcherbak, L. Ganushchak-Yefimenko, Martin Paumer, Tetiana Bukoros, Gabriela Čurgaliová, M. Zachar
The contribution deals with the influence of the operating loading on the flow characteristics of the hydraulic pump under laboratory conditions. In the test, a new toothed hydraulic pump and hydraulic oil with kinematic viscosity at 40°C, ν = 64.2 mm2 .s-1 were used. The operational loading was measured during the most difficult agrotechnical operation – ploughing, at which the loading of the hydraulic pump is the greatest. Laboratory testing was determined for 200 hours, and the flow characteristics had been detected at 50 hours intervals. Measurement of the flow characteristics was performed at rated speed n = 1,000 rpm. Measurement of the flow characteristics was carried out in dependence on the loading pressure from p = 0 MPa to p = 20 MPa. When p = 0 MPa, the value reached n = 91.70% and when p = 20 MPa, n = 86.68%. Running-in of the hydraulic pump lasted 150 hours, with an increase of the flow characteristics Δηvol = 1.36% (p = 10 MPa) compared to the initial state. After working for 200 hours, the flow rate of the hydraulic pump decreases compared to 150 hours.
{"title":"Experimental testing of the influence of the operating loading on the flow\u0000characteristics of hydraulic pump","authors":"J. Kosiba, Z. Tkáč, J. Jablonicky, V. Shcherbak, L. Ganushchak-Yefimenko, Martin Paumer, Tetiana Bukoros, Gabriela Čurgaliová, M. Zachar","doi":"10.17531/ein.2022.3.19","DOIUrl":"https://doi.org/10.17531/ein.2022.3.19","url":null,"abstract":"The contribution deals with the influence of the operating loading on the flow characteristics of the hydraulic pump under laboratory conditions. In the test, a new toothed hydraulic pump and hydraulic oil with kinematic viscosity at 40°C, ν = 64.2 mm2\u0000.s-1 were used. The operational loading was measured during the most difficult agrotechnical operation – ploughing, at which the loading of the hydraulic pump is the greatest. Laboratory testing was determined for 200 hours, and the flow characteristics had been detected at 50 hours intervals. Measurement of the flow characteristics was performed at rated speed n = 1,000 rpm. Measurement of the flow characteristics was carried out in dependence on the loading pressure from p = 0 MPa to p = 20 MPa. When p = 0 MPa, the value reached n = 91.70% and when p = 20 MPa, n = 86.68%. Running-in of the hydraulic pump lasted 150 hours, with an increase of the flow characteristics Δηvol = 1.36% (p = 10 MPa) compared to the initial state. After working for 200 hours, the flow rate of the hydraulic pump decreases compared to 150 hours.","PeriodicalId":50549,"journal":{"name":"Eksploatacja I Niezawodnosc-Maintenance and Reliability","volume":"422 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2022-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77235701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}