It is required to sake methods to improve the power plant performance. Most of the proposed methods can be commenced only in the design stapes. However, the main question of this study is “What can we do to improve the performance of a running power plant?” The first answer to this question is that monitoring the site and periodic overhaul can keep a power plant in its acceptable condition. However, this answer is very qualitatively and needs more precise information like which parameters shall be monitored or which equipment needs more care in the overhaul. In this study, important parameters and the method of their calculations are introduced that must be monitored and compared. Six similar gas turbine power cycles were selected to be compared deeply during a day in this study. In this way, many data were collected every five minutes. Unlike most of the previous studies, this one concerns with maintenance policy and repair strategy. Results of this comparison lead to answer to these questions that which equipment needs special care? Finally, it was shown that in each unit, which equipment needs more attention and which one can be considered as a standard for the others.
{"title":"Comparison of six gas turbine power cycle, a key to improve power plants","authors":"A. Golneshan, H. Nemati","doi":"10.1051/MECA/2021005","DOIUrl":"https://doi.org/10.1051/MECA/2021005","url":null,"abstract":"It is required to sake methods to improve the power plant performance. Most of the proposed methods can be commenced only in the design stapes. However, the main question of this study is “What can we do to improve the performance of a running power plant?” The first answer to this question is that monitoring the site and periodic overhaul can keep a power plant in its acceptable condition. However, this answer is very qualitatively and needs more precise information like which parameters shall be monitored or which equipment needs more care in the overhaul. In this study, important parameters and the method of their calculations are introduced that must be monitored and compared. Six similar gas turbine power cycles were selected to be compared deeply during a day in this study. In this way, many data were collected every five minutes. Unlike most of the previous studies, this one concerns with maintenance policy and repair strategy. Results of this comparison lead to answer to these questions that which equipment needs special care? Finally, it was shown that in each unit, which equipment needs more attention and which one can be considered as a standard for the others.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73967170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surface characteristics play a very important role in medical implants and among surface features, surface roughness is very effective in some medical applications. Among the various methods used to improve surface roughness, magnetic abrasive finishing (MAF) process has been widely used in medical engineering. In this study, the effect of abrasive particle morphology along with four other process parameters, including type of work metal, finishing time, speed of finishing operation, and the type of abrasive powder were experimentally evaluated. Full factorial technique was used for design of experiment. Three commonly used metals in orthopedic implants i.e., Ti-6Al-4V alloy, AZ31 alloy and austenitic stainless-steel 316LVM, were selected for this study. Also, two types of magnetic abrasive particles with different shapes (spherical and rod-shaped) were considered in the experiments. The results of the experiments indicated that the morphology of the abrasive particles and the finishing time had the greatest effect on surface roughness and using rod-shaped abrasive particles resulted in better surface quality comparing to the spherical particles. Besides, the surface quality of steel 316LVM after MAF was the best among the other examined metals. Interaction plots of ANOVA also showed that interactions of material with morphology of abrasive particles, and material with machining time were found to be reasonably significant.
{"title":"Effect of abrasive particle morphology along with other influencing parameters in magnetic abrasive finishing process","authors":"F. Ahmadi, Hassan Beiramlou, P. Yazdi","doi":"10.1051/MECA/2021013","DOIUrl":"https://doi.org/10.1051/MECA/2021013","url":null,"abstract":"Surface characteristics play a very important role in medical implants and among surface features, surface roughness is very effective in some medical applications. Among the various methods used to improve surface roughness, magnetic abrasive finishing (MAF) process has been widely used in medical engineering. In this study, the effect of abrasive particle morphology along with four other process parameters, including type of work metal, finishing time, speed of finishing operation, and the type of abrasive powder were experimentally evaluated. Full factorial technique was used for design of experiment. Three commonly used metals in orthopedic implants i.e., Ti-6Al-4V alloy, AZ31 alloy and austenitic stainless-steel 316LVM, were selected for this study. Also, two types of magnetic abrasive particles with different shapes (spherical and rod-shaped) were considered in the experiments. The results of the experiments indicated that the morphology of the abrasive particles and the finishing time had the greatest effect on surface roughness and using rod-shaped abrasive particles resulted in better surface quality comparing to the spherical particles. Besides, the surface quality of steel 316LVM after MAF was the best among the other examined metals. Interaction plots of ANOVA also showed that interactions of material with morphology of abrasive particles, and material with machining time were found to be reasonably significant.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84204147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To promote the engineering application of composite transmission of high speed curve face gear, which consists of a cylindrical gear and a high speed curve face gear, the analysis of tooth bending stress should be taken into consideration. High speed curve face gear pair is a new type of curve face gear pair. Combined with the principle of high speed cam and curve face gear pair transmission, it can transfer the axial/rotation composite motion and power between two intersecting shafts. Based on the gear engagement principle, the gear meshing coordinate system was established and the fundamental of the high speed composite transmission was expounded. Combined with the tooth profile equation of generating gear, the tooth surface equation of high speed curve face gear was gained. Tooth force, contact ratio and normal load distribution were calculated. Then the tooth bending stress of high speed curve face gear during the transmission was calculated and analyzed in detail. Influence of basic parameters on tooth bending stress was discussed. Finally, the simulation and measurement experiment of tooth bending stress was carried out. By the comparison analysis of simulation, experiment and theory, the correctness of tooth bending stress calculation method was verified, which has important guiding significance for the further research of high speed curve face gear of composite transmission.
{"title":"Tooth bending stress analysis of high speed curve face gear of composite transmission","authors":"Yongquan Yu, Chao Lin, Yanan Hu","doi":"10.1051/MECA/2021021","DOIUrl":"https://doi.org/10.1051/MECA/2021021","url":null,"abstract":"To promote the engineering application of composite transmission of high speed curve face gear, which consists of a cylindrical gear and a high speed curve face gear, the analysis of tooth bending stress should be taken into consideration. High speed curve face gear pair is a new type of curve face gear pair. Combined with the principle of high speed cam and curve face gear pair transmission, it can transfer the axial/rotation composite motion and power between two intersecting shafts. Based on the gear engagement principle, the gear meshing coordinate system was established and the fundamental of the high speed composite transmission was expounded. Combined with the tooth profile equation of generating gear, the tooth surface equation of high speed curve face gear was gained. Tooth force, contact ratio and normal load distribution were calculated. Then the tooth bending stress of high speed curve face gear during the transmission was calculated and analyzed in detail. Influence of basic parameters on tooth bending stress was discussed. Finally, the simulation and measurement experiment of tooth bending stress was carried out. By the comparison analysis of simulation, experiment and theory, the correctness of tooth bending stress calculation method was verified, which has important guiding significance for the further research of high speed curve face gear of composite transmission.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84351891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qin He, P. Zhang, Shunxin Cao, Ruijun Zhang, Qing Zhang
Aiming at the inconsistency between the vibration of the car and the car frame in the actual operation of a high-speed elevator and the horizontal vibration caused by the roughness excitation of the guide rail, this study designs a gas–liquid active guide shoe and establishes a horizontal vibration model of the 8-DOF high-speed elevator car system separated from the car and the car frame. Then, the correctness of the model is verified by experiments. Based on this, a fuzzy neural network intelligent vibration reduction controller based on the Mamdani model is designed and simulated by MATLAB. The results show that the root mean square value, mean value, and maximum value of vibration acceleration are reduced by more than 55% after using the fuzzy neural network control method, and the suppression effect is better than that of BP neural network control. Therefore, the intelligent vibration absorption controller designed by this research institute can effectively suppress the horizontal vibration of high-speed elevators.
{"title":"Intelligent control of horizontal vibration of high-speed elevator based on gas–liquid active guide shoes","authors":"Qin He, P. Zhang, Shunxin Cao, Ruijun Zhang, Qing Zhang","doi":"10.1051/MECA/2020100","DOIUrl":"https://doi.org/10.1051/MECA/2020100","url":null,"abstract":"Aiming at the inconsistency between the vibration of the car and the car frame in the actual operation of a high-speed elevator and the horizontal vibration caused by the roughness excitation of the guide rail, this study designs a gas–liquid active guide shoe and establishes a horizontal vibration model of the 8-DOF high-speed elevator car system separated from the car and the car frame. Then, the correctness of the model is verified by experiments. Based on this, a fuzzy neural network intelligent vibration reduction controller based on the Mamdani model is designed and simulated by MATLAB. The results show that the root mean square value, mean value, and maximum value of vibration acceleration are reduced by more than 55% after using the fuzzy neural network control method, and the suppression effect is better than that of BP neural network control. Therefore, the intelligent vibration absorption controller designed by this research institute can effectively suppress the horizontal vibration of high-speed elevators.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78781245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Da-lian Yang, Zhang Fanyu, J. Miao, Hongxian Zhang, Renjie Li, Tao Jie
Misalignment fault is the main factor that affects the normal running of dual-rotor system. Quantitative identification the misalignment fault is an important way to ensure the safe and stable service of the dual-rotor system, while the identification accuracy of traditional methods is low. Aiming at the above problems, this paper proposed a dual-rotor misalignment fault quantitative identification method based on DBN and D-S evidence theory improved by mutual information measure (MIMD-S). Seven groups experiments were conducted and several vibration signals were collected. By comparing it with the traditional methods D-S, and Pignistic improved D-S (PD-S) evidence theory, the results show that the method proposed in this paper improves the accuracy of the misalignment fault quantitative identification of the dual-rotor, the identification error rate was only 0.36%.
{"title":"Dual-rotor misalignment fault quantitative identification based on DBN and improved D-S evidence theory","authors":"Da-lian Yang, Zhang Fanyu, J. Miao, Hongxian Zhang, Renjie Li, Tao Jie","doi":"10.1051/MECA/2021022","DOIUrl":"https://doi.org/10.1051/MECA/2021022","url":null,"abstract":"Misalignment fault is the main factor that affects the normal running of dual-rotor system. Quantitative identification the misalignment fault is an important way to ensure the safe and stable service of the dual-rotor system, while the identification accuracy of traditional methods is low. Aiming at the above problems, this paper proposed a dual-rotor misalignment fault quantitative identification method based on DBN and D-S evidence theory improved by mutual information measure (MIMD-S). Seven groups experiments were conducted and several vibration signals were collected. By comparing it with the traditional methods D-S, and Pignistic improved D-S (PD-S) evidence theory, the results show that the method proposed in this paper improves the accuracy of the misalignment fault quantitative identification of the dual-rotor, the identification error rate was only 0.36%.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76319633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fanming Meng, Sheng Yang, Zhi-tao Cheng, Yong Zheng, Bin Wang
A non-Newtonian thermal elastohydrodynamic lubrication (TEHL) model for the elliptic contact is established, into which the inertia forces of the lubricant is incorporated. In doing so, the film pressure and film temperature are solved using the associated equations. Meanwhile, the elastic deformation is calculated with the discrete convolution and fast Fourier transform (DC-FFT) method. A film thickness experiment is conducted to validate the TEHL model considering the inertia forces. Further, effects of the inertia forces on the TEHL performances are studied at different operation conditions. The results show that when the inertia forces are considered, the central and minimum film thicknesses increase and film temperature near the inlet increases obviously. Moreover, the inertial solution of the central film thickness is closer to the experimental result compared with its inertialess value.
{"title":"Effect of fluid inertia force on thermal elastohydrodynamic lubrication of elliptic contact","authors":"Fanming Meng, Sheng Yang, Zhi-tao Cheng, Yong Zheng, Bin Wang","doi":"10.1051/MECA/2021010","DOIUrl":"https://doi.org/10.1051/MECA/2021010","url":null,"abstract":"A non-Newtonian thermal elastohydrodynamic lubrication (TEHL) model for the elliptic contact is established, into which the inertia forces of the lubricant is incorporated. In doing so, the film pressure and film temperature are solved using the associated equations. Meanwhile, the elastic deformation is calculated with the discrete convolution and fast Fourier transform (DC-FFT) method. A film thickness experiment is conducted to validate the TEHL model considering the inertia forces. Further, effects of the inertia forces on the TEHL performances are studied at different operation conditions. The results show that when the inertia forces are considered, the central and minimum film thicknesses increase and film temperature near the inlet increases obviously. Moreover, the inertial solution of the central film thickness is closer to the experimental result compared with its inertialess value.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90149531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Agathe Reille, V. Champaney, F. Daim, Y. Tourbier, Nicolas Hascoet, D. González, E. Cueto, J. Duval, F. Chinesta
Solving mechanical problems in large structures with rich localized behaviors remains a challenging issue despite the enormous advances in numerical procedures and computational performance. In particular, these localized behaviors need for extremely fine descriptions, and this has an associated impact in the number of degrees of freedom from one side, and the decrease of the time step employed in usual explicit time integrations, whose stability scales with the size of the smallest element involved in the mesh. In the present work we propose a data-driven technique for learning the rich behavior of a local patch and integrate it into a standard coarser description at the structure level. Thus, localized behaviors impact the global structural response without needing an explicit description of that fine scale behaviors.
{"title":"Learning data-driven reduced elastic and inelastic models of spot-welded patches","authors":"Agathe Reille, V. Champaney, F. Daim, Y. Tourbier, Nicolas Hascoet, D. González, E. Cueto, J. Duval, F. Chinesta","doi":"10.1051/MECA/2021031","DOIUrl":"https://doi.org/10.1051/MECA/2021031","url":null,"abstract":"Solving mechanical problems in large structures with rich localized behaviors remains a challenging issue despite the enormous advances in numerical procedures and computational performance. In particular, these localized behaviors need for extremely fine descriptions, and this has an associated impact in the number of degrees of freedom from one side, and the decrease of the time step employed in usual explicit time integrations, whose stability scales with the size of the smallest element involved in the mesh. In the present work we propose a data-driven technique for learning the rich behavior of a local patch and integrate it into a standard coarser description at the structure level. Thus, localized behaviors impact the global structural response without needing an explicit description of that fine scale behaviors.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76894599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The accuracy of nucleic acid extraction and diagnosis depends on the sealing performance of the pipetting device. The rubber seal ring at the front end of the pipette shaft is a critical component for ensuring the sealing performance of the pipetting device. In this study, an accurate prediction and analysis were made on the fatigue life of the pipette shaft seal ring. ABAQUS was used to simulate the assembly process of pipette shaft seal ring and disposable tip, and the dangerous cross-section segments on the seal rings were preliminarily identified according to a stress nephogram. Based on the continuum damage mechanics theory, the fatigue life prediction model was built where the effective strain was taken as a damage parameter, and the fatigue life of the dangerous cross-section of the pipette shaft seal ring was calculated. By observing failed seal rings in actual use, it was found that the worn positions of the failed seal rings were the same as the sites of the shortest-lived node segments, thus verifying the accuracy of fatigue life prediction model and fatigue life analysis.
{"title":"Effective strain range-based prediction and analysis of the fatigue life of pipette shaft seal ring","authors":"Chenxue Wang, Q. Su, Zeng Huang, Z. Lian, Yu Liu","doi":"10.1051/meca/2021038","DOIUrl":"https://doi.org/10.1051/meca/2021038","url":null,"abstract":"The accuracy of nucleic acid extraction and diagnosis depends on the sealing performance of the pipetting device. The rubber seal ring at the front end of the pipette shaft is a critical component for ensuring the sealing performance of the pipetting device. In this study, an accurate prediction and analysis were made on the fatigue life of the pipette shaft seal ring. ABAQUS was used to simulate the assembly process of pipette shaft seal ring and disposable tip, and the dangerous cross-section segments on the seal rings were preliminarily identified according to a stress nephogram. Based on the continuum damage mechanics theory, the fatigue life prediction model was built where the effective strain was taken as a damage parameter, and the fatigue life of the dangerous cross-section of the pipette shaft seal ring was calculated. By observing failed seal rings in actual use, it was found that the worn positions of the failed seal rings were the same as the sites of the shortest-lived node segments, thus verifying the accuracy of fatigue life prediction model and fatigue life analysis.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90475141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mechanics & Industry publishes all articles in Open Access from January 2021","authors":"R. Dufour, E. Arquis, Ariana Fuga","doi":"10.1051/MECA/2021020","DOIUrl":"https://doi.org/10.1051/MECA/2021020","url":null,"abstract":"","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74996675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flow in a branched channel is studied experimentally using the PIV technique. The presented study is concentrated on clarifying the dynamical behaviour in individual branches. The 11 branches issuing from the main channel perpendicularly, all channels are of rectangular cross-section. First, the time-mean flow-field is shown, then the flow dynamics is investigated using the OPD method. Flow patterns and frequencies are evaluated in three selected branches. The separated flow in branches exhibits highly dynamical behaviour, which differs substantially in the branches close to the inflow, in the main channel middle and close to its end. The typical topologies and frequencies of the detected quasi-periodical structures in the channel braches are shown in the study. Mostly, the flow-fields are populated by trains of vortices with alternating orientation and saddle-like structures. The flow-field close to the channel walls affects heat transfer process between the wall and fluid.
{"title":"Dynamics of flow in a branching channel","authors":"V. Uruba, P. Procházka, V. Skála","doi":"10.1051/MECA/2021014","DOIUrl":"https://doi.org/10.1051/MECA/2021014","url":null,"abstract":"Flow in a branched channel is studied experimentally using the PIV technique. The presented study is concentrated on clarifying the dynamical behaviour in individual branches. The 11 branches issuing from the main channel perpendicularly, all channels are of rectangular cross-section. First, the time-mean flow-field is shown, then the flow dynamics is investigated using the OPD method. Flow patterns and frequencies are evaluated in three selected branches. The separated flow in branches exhibits highly dynamical behaviour, which differs substantially in the branches close to the inflow, in the main channel middle and close to its end. The typical topologies and frequencies of the detected quasi-periodical structures in the channel braches are shown in the study. Mostly, the flow-fields are populated by trains of vortices with alternating orientation and saddle-like structures. The flow-field close to the channel walls affects heat transfer process between the wall and fluid.","PeriodicalId":49018,"journal":{"name":"Mechanics & Industry","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83980529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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