In this study, a vibration analysis method is presented based on the substructure elimination method for a Bernoulli-Euler beam. Vibration analysis using modal analysis is effective for reducing the degrees of freedom and enables the analysis of a beam on which actuators and sensors are installed. When mechanical impedances are installed at the boundaries or the beam is coupled to other structures, a free-free beam is employed for conventional modal analysis using continuous functions. However, conventional modal analysis provides inaccurate simulation results when the coupled mechanical impedances considering the characteristic impedances of the beam are large. To address this issue, the modal analysis of a beam using the substructure elimination method was proposed in this study. Because the substructure elimination method for beams was only briefly reported on by the first author, several problems currently exist. To solve these problems, a substructure elimination method is proposed using a simply supported beam in addition to a guided-guided beam. Additionally, a new formulation method based on constraint conditions was proposed as a versatile method for setting arbitrary boundary conditions. The appropriate length, line density, and bending stiffness of the elimination regions, and the highest order of the eigenmode, were determined through simulations. The effectiveness of the proposed method was then verified by comparing the simulation results of the proposed method and exact solutions obtained using the boundary conditions. Based on a comparison with the simulation results of conventional modal analysis using a free-free beam, the precision of the proposed method is significantly higher than that of conventional modal analysis.
{"title":"Substructure elimination method for evaluating bending vibration of beams","authors":"Keisuke YAMADA, Jinchen JI","doi":"10.1299/mej.23-00293","DOIUrl":"https://doi.org/10.1299/mej.23-00293","url":null,"abstract":"In this study, a vibration analysis method is presented based on the substructure elimination method for a Bernoulli-Euler beam. Vibration analysis using modal analysis is effective for reducing the degrees of freedom and enables the analysis of a beam on which actuators and sensors are installed. When mechanical impedances are installed at the boundaries or the beam is coupled to other structures, a free-free beam is employed for conventional modal analysis using continuous functions. However, conventional modal analysis provides inaccurate simulation results when the coupled mechanical impedances considering the characteristic impedances of the beam are large. To address this issue, the modal analysis of a beam using the substructure elimination method was proposed in this study. Because the substructure elimination method for beams was only briefly reported on by the first author, several problems currently exist. To solve these problems, a substructure elimination method is proposed using a simply supported beam in addition to a guided-guided beam. Additionally, a new formulation method based on constraint conditions was proposed as a versatile method for setting arbitrary boundary conditions. The appropriate length, line density, and bending stiffness of the elimination regions, and the highest order of the eigenmode, were determined through simulations. The effectiveness of the proposed method was then verified by comparing the simulation results of the proposed method and exact solutions obtained using the boundary conditions. Based on a comparison with the simulation results of conventional modal analysis using a free-free beam, the precision of the proposed method is significantly higher than that of conventional modal analysis.","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136367489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As a method for cleaning the nozzle of clinical analyzers with high cleaning efficiency, ultrasonic cleaning was selected because the cleaning mechanism can be miniaturized and its effect on dispensing accuracy is negligible. As for nozzle cleaning, it is necessary to meet two requirements: (i) suppress the wetting range of the nozzle inserted in the chamber of the ultrasonic cleaner and (ii) generate cavitation at a depth of a few millimeters from the liquid surface. To meet those requirements, a new ultrasonic cleaner with an L-shaped cleaning head for high-efficiency cleaning of the nozzle is proposed. The cleaning head is composed of two vibration plates at its tip to concentrate the sound pressure in the cleaning area, and the shape of the head enables the vibration phase of the ultrasonic-irradiation surfaces of the plates to be reversed with a single bolt-clamped Langevin-type ultrasonic transducer (BLT). The BLT with the proposed cleaning head has three resonant frequencies: that of the BLT, fBLT, that of the lower plate, fL-P, and that of the upper plate, fU-P. At fBLT, the BLT expands and contracts in the longitudinal direction. At fL-P and fU-P, deformation of each vibration plate is large. By setting the resonance frequencies in increasing order of magnitude, i.e., fL-P, fBLT, and fU-P, it is possible to reverse the phases of the two vibration plates by driving the BLT at fBLT. It was experimentally confirmed that the sound pressure can be concentrated in the cleaning area of the cleaning head by driving the BLT at fBLT.
{"title":"An ultrasonic cleaner for cleaning the tip of a sampling nozzle by reversed phase driving of two vibrating plates (Translated)","authors":"Yosuke HORIE, Katsuhiko KIMURA, Akihiro NOJIMA, Hiroyuki TAKAYAMA, Kohei NONAKA","doi":"10.1299/mej.23-00349","DOIUrl":"https://doi.org/10.1299/mej.23-00349","url":null,"abstract":"As a method for cleaning the nozzle of clinical analyzers with high cleaning efficiency, ultrasonic cleaning was selected because the cleaning mechanism can be miniaturized and its effect on dispensing accuracy is negligible. As for nozzle cleaning, it is necessary to meet two requirements: (i) suppress the wetting range of the nozzle inserted in the chamber of the ultrasonic cleaner and (ii) generate cavitation at a depth of a few millimeters from the liquid surface. To meet those requirements, a new ultrasonic cleaner with an L-shaped cleaning head for high-efficiency cleaning of the nozzle is proposed. The cleaning head is composed of two vibration plates at its tip to concentrate the sound pressure in the cleaning area, and the shape of the head enables the vibration phase of the ultrasonic-irradiation surfaces of the plates to be reversed with a single bolt-clamped Langevin-type ultrasonic transducer (BLT). The BLT with the proposed cleaning head has three resonant frequencies: that of the BLT, fBLT, that of the lower plate, fL-P, and that of the upper plate, fU-P. At fBLT, the BLT expands and contracts in the longitudinal direction. At fL-P and fU-P, deformation of each vibration plate is large. By setting the resonance frequencies in increasing order of magnitude, i.e., fL-P, fBLT, and fU-P, it is possible to reverse the phases of the two vibration plates by driving the BLT at fBLT. It was experimentally confirmed that the sound pressure can be concentrated in the cleaning area of the cleaning head by driving the BLT at fBLT.","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meshless methods inherently do not require mesh topologies and are practically used for solving continuum equations. However, these methods generally tend to have a higher computational load than conventional mesh-based methods because calculation stencils for spatial discretization become large. In this study, a novel approach for the use of compact stencils in meshless methods is proposed, called the mesh-constrained discrete point (MCD) approach. The MCD approach introduces a Cartesian mesh system to the background of a domain. And the approach rigorously constrains the distribution of discrete points (DPs) in each mesh by solving a dynamic problem with nonlinear constraints. This can avoid the heterogeneity of the DP distribution at the mesh-size level and impose compact stencils with a fixed degree of freedom for derivative evaluations. A fundamental formulation for arrangements of DPs and an application to unsteady Stokes flows are presented in this paper. Numerical tests were performed for the distribution of DPs and flow problems in co-axial and eccentric circular channels. The proposed MCD approach achieved a reasonable distribution of DPs independently of the spatial resolution with a few iterations in pre-processing. Additionally, solutions using the obtained DP distributions in Stokes flow problems were in good agreement with theoretical and reference solutions. The results also confirmed that the numerical accuracies of velocity and pressure achieved the expected convergence order, even when compact stencils were used.
{"title":"A particle-based method using the mesh-constrained discrete point approach for two-dimensional Stokes flows","authors":"Takeharu Matsuda, Kohsuke Tsukui, Satoshi Ii","doi":"10.1299/mej.22-00204","DOIUrl":"https://doi.org/10.1299/mej.22-00204","url":null,"abstract":"Meshless methods inherently do not require mesh topologies and are practically used for solving continuum equations. However, these methods generally tend to have a higher computational load than conventional mesh-based methods because calculation stencils for spatial discretization become large. In this study, a novel approach for the use of compact stencils in meshless methods is proposed, called the mesh-constrained discrete point (MCD) approach. The MCD approach introduces a Cartesian mesh system to the background of a domain. And the approach rigorously constrains the distribution of discrete points (DPs) in each mesh by solving a dynamic problem with nonlinear constraints. This can avoid the heterogeneity of the DP distribution at the mesh-size level and impose compact stencils with a fixed degree of freedom for derivative evaluations. A fundamental formulation for arrangements of DPs and an application to unsteady Stokes flows are presented in this paper. Numerical tests were performed for the distribution of DPs and flow problems in co-axial and eccentric circular channels. The proposed MCD approach achieved a reasonable distribution of DPs independently of the spatial resolution with a few iterations in pre-processing. Additionally, solutions using the obtained DP distributions in Stokes flow problems were in good agreement with theoretical and reference solutions. The results also confirmed that the numerical accuracies of velocity and pressure achieved the expected convergence order, even when compact stencils were used.","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44063508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Relationship between the reciprocity of transfer functions for mechanical vibration systems and optimal design formulas of dynamic vibration absorbers","authors":"T. Asami","doi":"10.1299/mej.21-00362","DOIUrl":"https://doi.org/10.1299/mej.21-00362","url":null,"abstract":"","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45811489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Biness Lukwesa, Naoya Takahashi, Kengo Suzuki, Yutaka Tabe, T. Chikahisa
{"title":"Analysis of effective measures for power fluctuation mitigation of geographically distributed wind and solar power","authors":"Biness Lukwesa, Naoya Takahashi, Kengo Suzuki, Yutaka Tabe, T. Chikahisa","doi":"10.1299/mej.21-00154","DOIUrl":"https://doi.org/10.1299/mej.21-00154","url":null,"abstract":"","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66396574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noriaki Yasugi, Naoya Odaira, D. Ito, K. Ito, Yasushi Saito
{"title":"Pressure drop evaluation based on two-phase flow observation in packed bed system","authors":"Noriaki Yasugi, Naoya Odaira, D. Ito, K. Ito, Yasushi Saito","doi":"10.1299/mej.21-00437","DOIUrl":"https://doi.org/10.1299/mej.21-00437","url":null,"abstract":"","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66397783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Vibration analysis of liquid in an axisymmetric tank covered by a diaphragm","authors":"M. Utsumi","doi":"10.1299/mej.22-00022","DOIUrl":"https://doi.org/10.1299/mej.22-00022","url":null,"abstract":"","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66398668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The most dominant failure mode of piping components under seismic loading is fatigue failure with ratcheting. While it was confirmed via the experimental tests in the past, the Primary stress limit is applied to seismic loading to prevent plastic collapse. The plastic collapse due to seismic loading was first confirmed at Pipe-Fitting Dynamic Reliability Program (PFDRP) conducted by EPRI in 1980s. But, the mechanism and occurrence condition of this failure has not been clarified yet. In this research, a composite failure mode of the ratchet-induced collapse, which represents the behavior of the plastic collapse failure induced by ratchet deformation, is introduced. The transition of the failure modes along ratcheting is explained with the seismic failure mode map which identifies the occurrence condition of ratcheting and first-excursion failure, and the X-Y trajectory, which explains the excitation condition of structures under ratcheting, is introduced to project the transition. With the X-Y trajectory and the occurrence condition of the plastic collapse, this study conceptually proposes the prediction approach of the ratchet-induced collapse without the simulation analyses.
{"title":"Occurrence of plastic collapse under ratcheting due to gravity and seismic loading","authors":"Satoru Kai, M. Ichimiya, N. Kasahara","doi":"10.1299/mej.21-00321","DOIUrl":"https://doi.org/10.1299/mej.21-00321","url":null,"abstract":"The most dominant failure mode of piping components under seismic loading is fatigue failure with ratcheting. While it was confirmed via the experimental tests in the past, the Primary stress limit is applied to seismic loading to prevent plastic collapse. The plastic collapse due to seismic loading was first confirmed at Pipe-Fitting Dynamic Reliability Program (PFDRP) conducted by EPRI in 1980s. But, the mechanism and occurrence condition of this failure has not been clarified yet. In this research, a composite failure mode of the ratchet-induced collapse, which represents the behavior of the plastic collapse failure induced by ratchet deformation, is introduced. The transition of the failure modes along ratcheting is explained with the seismic failure mode map which identifies the occurrence condition of ratcheting and first-excursion failure, and the X-Y trajectory, which explains the excitation condition of structures under ratcheting, is introduced to project the transition. With the X-Y trajectory and the occurrence condition of the plastic collapse, this study conceptually proposes the prediction approach of the ratchet-induced collapse without the simulation analyses.","PeriodicalId":45233,"journal":{"name":"Mechanical Engineering Journal","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66397439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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