{"title":"ネマティック液晶の２重円筒間せん断流れにおける分子配向場の非定常挙動","authors":"Naoya ONIMARU, Tomohiro TSUJI, Shigeomi CHONO","doi":"10.1299/transjsme.23-00049","DOIUrl":"https://doi.org/10.1299/transjsme.23-00049","url":null,"abstract":"Transient behaviors of molecular orientation field of nematic liquid crystal (4-n-4’-octylcyanobiphenyl) under shear flows between concentric cylinders have been numerically investigated using the Leslie-Ericksen continuum theory in which the molecular orientation is represented with a unit vector, called the director. As well as the rotation speed of an inner cylinder, the director anchoring conditions at the inner and outer cylinders are chosen as simulation parameters to obtain four different cases of director initial profiles, which are homeotropic, hybrid, planar, and twist cases. After the imposition of the shear flow, the director start rotating within the shear plane, increasing the curvature energy of the director field. When the energy exceeds a certain critical value, the director start escaping from the shear plane, called the out-of-plane behavior. Because the escaping direction (i.e., either +z or -z directions) is the stochastic choice, the director field is randomly separated into the positive and negative out-of-plane regions. Then, the spatially distributed two out-of-plane regions are transformed into line defect structures. The spatial patterns of the out-of-plane regions and the line defect structures strongly depends on the director anchoring conditions, and no patterns are found for the twist case. The evolutions of torques of the inner cylinder is also estimated from the simulation results for four cases, and the oscillatory behavior of the torque is found for the homeotropic case.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135402383","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":"微小柱せん断試験によるエポキシ接着剤の接着強度に及ぼす環境負荷の影響の検討","authors":"Yasuhiro YAMAZAKI, Masatoshi FUJIWARA","doi":"10.1299/transjsme.23-00212","DOIUrl":"https://doi.org/10.1299/transjsme.23-00212","url":null,"abstract":"Epoxy resins, one of the high-performance polymer materials, have been widely used as an adhesive because of their excellent strength and durability due to their cross-linked network structure. It is necessary to understand the adhesion mechanism to ensure their reliability as structural adhesives. It is concerned that environmental attacks, such as high temperature and humidity, degrade the bonding strength of the adhesive structure. In order to understand the degradation mechanism by environmental attacks, it is necessary to evaluate the intrinsic bonding strength of adhesive systems by a quantitative test method. This study proposed a novel test method to evaluate the shear bonding strength using a small columnar resin formed on the metal adherend's surface and investigated the adherend and environmental degradation effects on the bonding strength using the proposed method. The experimental results revealed that the bonding strength of the epoxy adhesive was affected by the environmental attack. The bonding strength increased regardless of the substrate material after the low-humidity and high-temperature exposure. On the other hand, the effect of the high humidity attack on the bonding strength was different depending on the adherend: the bonding strength of SUS304 decreased, on the other hand, that of A5052 increased. The fracture morphologies also changed in the case of A5052 adherend after the high humidity and temperature exposure. AlO(OH) was formed on the A5052 adherend surface after high humidity and temperature exposure, which might have affected its bonding strength.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135954451","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":"レール開口部の繰り返し車両通過時における軌道部材の強度評価及び走行安全性の基礎的検討","authors":"Katsutoshi SHIOTA, Yuki NISHINOMIYA, Shintaro YASUDA","doi":"10.1299/transjsme.23-00086","DOIUrl":"https://doi.org/10.1299/transjsme.23-00086","url":null,"abstract":"In a section which a wireless train control system is installed and the track circuit is removed, it is difficult to detect rail broken. Under such circumstances, the vehicle is assumed to run repeatedly on rail gaps until rail broken is found by rail inspection or other means. Therefore, this study investigated the strength of the track components under condition of repeated passage at a rail broken section. Specifically, we fabricated a new falling weight test equipment which can apply the impact load of a vehicle passing through a rail broken section and then, the strength of track components was experimentally investigated by conducting repeated falling weight test. This test evaluates the plastic deformation of the rails and functional deterioration of the rail fastenings system in response to impact loads. In addition, in order to evaluate running safety considering repeated passage at a rail broken section, we created a vehicle running simulation model that takes into account damage condition of track components after a falling weight test. The results of the running simulation confirmed that the plastic deformation of the rails and damage to the rail fastening systems considered in this study do not have a significant impact on running safety.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136204446","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":"数値解析による流体音響デバイスの挙動に関する研究","authors":"Taichi FUJIMOTO, Tatsuya ISHII, Shunji ENOMOTO, Hitoshi ISHIKAWA","doi":"10.1299/transjsme.23-00113","DOIUrl":"https://doi.org/10.1299/transjsme.23-00113","url":null,"abstract":"This paper describes computational study to investigate the aero-acoustic mechanism observed in Hartmann generator when under-expanded supersonic jet is blown from a convergent nozzle. The Hartmann generator, composed of a nozzle and a resonance tube with small distance, is known to radiate much higher amplitude of tonal sound than a free jet without any interaction. Aiming at establishing compact and efficient fluidic actuators, the authors tried to clarify the fluid-dynamic and acoustic behaviors of this special device by use of computational tool, i.e., UPACS-LES of Japan aerospace exploration agency（JAXA）. The computational results suggested existence of the JRG mode, an alternative flow motion between the nozzle and the resonance tube. This flow motion drives strong pressure fluctuation and forms sound field in the far field. The computational results complied with the fundamental acoustic characteristics in the former studies, such as far-field sound directivity and radiated acoustic power. Based on the results, it was confirmed that some parameters such as nozzle pressure ratio are predominant to intensify the acoustic power in the far field. Especially, the open-end location of the resonance tube governs the acoustic power when it is between Mach disk and shock cell end in the under-expanded supersonic jet.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"138 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135104549","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":"サッカーのボール奪取時のトランジション成立に対するチーム位置情報の貢献（Jリーグプロサッカー選手の公式戦の解析）","authors":"Satoki MURAI, Makoto AYABE, Takashi OYAMA, Kaito MITANI, Hideaki KUMAHARA, Shunsuke SUNAMI, Satoshi ISHIZAKI","doi":"10.1299/transjsme.23-00198","DOIUrl":"https://doi.org/10.1299/transjsme.23-00198","url":null,"abstract":"The purpose of this study was to clarify the factors that make transitions efficient using the positional information of the players. The independent variable in this analysis was the positional data gathered from the Vector X7 system (10 Hz) during 20 official matches of the second division of the Japan Professional Soccer League for the 2022 season. The positional data included metrics such as team convex area, length, width, foremost position, rearmost position, rightmost position, and leftmost position. Statistical analysis revealed that the team convex area, foremost position, rearmost position, and width were significantly higher during successful transitions than failed transitions (p = 0.032, p < 0.001, p < 0.001, and p = 0.030, respectively). Conversely, the leftmost position was significantly lower during successful transitions than failed transitions (p = 0.012). Moreover, the results obtained from the decision tree analysis demonstrated that the rearmost team position emerged as the most influential factor determining the success or failure of transitions. The results of the present investigation demonstrated that the positional information of the players at the time of ball recovery is an explanatory factor for efficient transitions. The novel contribution of this study is that the factor that determines efficient transitions was found to be the rearmost position and the leftmost position of the team at the time of ball recovery.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135508164","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":"Development of metal shock absorber for storage of nuclear spent fuel cask","authors":"Toru MATSUBARA, Ryota NAKAGAWA, Hideaki MITSUI, Yoshiyuki SAITO, Yuichi SAITO, Junichi KISHIMOTO, Hiroki TAMAKI","doi":"10.1299/transjsme.23-00162","DOIUrl":"https://doi.org/10.1299/transjsme.23-00162","url":null,"abstract":"Metal shock absorbers of nuclear spent fuel casks for storage have been developed. The shock absorbers are equipped at both ends of the cylindrical cask to reduce the impact force and maintain the safety functions of the cask in the event of an unexpected drop accident. As a countermeasure to meet long-term storage requirement (against material degradation), the shock absorber was designed with metal instead of usual wood and its energy absorption performance against 2.5 m height drop (maximum hypothetical handling height in nuclear power plants during storage) was evaluated. With the aim of reducing compression stiffness the metal shock absorber was designed from a perforated aluminum block. Two tests were done for static compression characteristics using cubic specimens and energy absorption capacity against 2.5 m drop using 1/4 scale mockup of metal shock absorber. In addition, a drop test using 1/10 scale mockup cask with metal shock absorbers confirmed that it could deform as assumed and reduce the applied acceleration on the cask to a safety level at crash. As a result of the finite element analysis of the cask with designed shock absorbers dropped from a height of 2.5 m that was verified by the drop test, the fitting portion between body and primary lid in the cask remained within elastic deformation thus confirming the design’s validity.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135007861","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":"A Study on 4-Axis Turning for Non-Axisymmetric 3D Surfaces - Creation of high-precision curved surfaces by synchronizing the spindle and rotary tool axis-","authors":"Yoshitaka MORIMOTO, Narimasa UEDA, Shion HAMANO, Akio HAYASHI","doi":"10.1299/transjsme.23-00153","DOIUrl":"https://doi.org/10.1299/transjsme.23-00153","url":null,"abstract":"A machining center is a common machine tool that can machine complex free-form surfaces such as the press mold, automobile’s cam profile. When these curved surfaces are machined by the conventional machining center and/or the grinding machine, it takes lot of time to complete with enough accuracy. In order to solve this problem, this study aims not only to improve the machining accuracy of this curved surface but also to make it possible to shorten the machining time using a CNC lathe. In this study, the NACS-Turning (Non-axisymmetric curved surface turning) method that we proposed originally was used. The spindle of C-Axis, the moving table with the cutting tool of X1-Axis, the other counter moving table of X2-Axis (without involved in shape creation, only used to suppress inertial force), the head stock of Z-Axis, and the tool rotation axis of B-Axis are adapted. In this 4-Axis machining method, all the axes are controlled with the synchronized manner. This method can machine the same rotational position of workpiece with the same cutting edge of the rotary tool. As an experiment, we compared 4-Axis machining with synchronized spindle and tool rotation, 3-Axis machining, and machining without synchronous rotation. Our new 4-Axis machining method with synchronized spindle and tool rotation reduced the form error from 323 ㎛ to 247 ㎛ and the surface roughness from Rz 9.6μm to Rz 3.7μm. Moreover, the repetitive machining resulted in error of 99.6μm and a surface roughness of Rz2.9μm.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136374037","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":"時間可変旋回羽根による予混合火炎挙動の安定化","authors":"Masaharu KOMIYAMA, Yusuke MIZUNO, Satoshi NISHIDA","doi":"10.1299/transjsme.23-00172","DOIUrl":"https://doi.org/10.1299/transjsme.23-00172","url":null,"abstract":"In this study, we aimed to stabilize premixed flame behaviors in a circular pipe with swirling flow. We constructed a system that automatically changes swirl vane angles according to the flame tip positions keeping the air ratio and flow rate. In addition, we tried to stabilize the flame behavior using this system, and simultaneously employed time-series PIV measurements in the flow fields in the circular pipe. The findings obtained in this study are shown below. (1) Under this experimental condition, it was shown that there was a positive and strong correlation between the flame tip positions and the integrated scattering intensity of tracer particles in a circular pipe with swirling flow. (2) Using the integrated scattering intensity of tracer particles as an index, the change of the flame tip positions was judged, and the swirl vane angle could be changed according to the behavior of the premixed flame. It was shown that keeping the flame tip positions within the circular pipe was possible. (3) While operating the flame position stabilization system, time-series PIV measurements simultaneously measured the flow fields near the flame tip. From the results, when the swirl vane angle was changed in the positive direction, an upstream-direction velocity region appeared by increasing the swirl intensity. After that, the flame propagated upstream along the formed upstream-direction velocity region.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135954465","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":"トポロジー最適化とマイクロポーラ弾性体の考え方に基づくリンク機構の構想設計法","authors":"Yurika SAYO, Takayuki YAMADA","doi":"10.1299/transjsme.23-00082","DOIUrl":"https://doi.org/10.1299/transjsme.23-00082","url":null,"abstract":"This paper presents a conceptual design approach for planar link mechanisms by utilizing continuum topology optimization based on micropolar continuum theory. To effectively simulate the behavior of link mechanisms as continuum elasticity, we introduce a mathematical model utilizing micropolar elasticity. Although topology optimization is commonly used for single mechanical components, extending it to mechanisms with multiple interconnected parts presents inherent challenges. To address these challenges, we model the link mechanism using micropolar elasticity, leveraging its bendiness-related material property, which can apply to topology optimization. Subsequently, we formulate a topology optimization problem to generate link mechanisms using our proposed model. The optimized structure achieves the desired motion and deformation characteristics like traditional linkages with proper degrees of freedom while minimizing the objective function that considers both output motion error and link compliance. The design variables of the topology optimization problem are defined using the Solid Isotropic Material with Penalization (SIMP) method, which is further updated using a gradient-based optimizer. The governing equations of linear micropolar elasticity are solved using the Finite Element Method (FEM). The effectiveness and validity of our proposed method are evaluated through numerical examples, which conclusively demonstrate its ability to synthesize the number, dimensions, and structure of link mechanisms.","PeriodicalId":485601,"journal":{"name":"Nihon kikai gakkai ronbunshu","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135104537","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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