著者

河原 康太 松田 直樹 北條 正樹 西川 雅章

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00582-16-00582, 2017 (Released:2017-05-25)

参考文献数

15

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Formulation based on the eigenfunction expansion is shown for second-harmonic generation simulations at a cylindrical interface. The displacement potentials of fundamental wave fields and second-harmonic fields are expressed as sums of eigenfunctions. The cylinder-matrix interface is assumed to be imperfect and modeled as a nonlinear spring interface for the purpose of considering roughness of the interface. Nonlinear equations in this model are dealt with the perturbation theory. The relational expression on the expansion coefficients of the fundamental waves and the second harmonics is shown. The results for the P wave incidence are demonstrated; although arbitrary incident wave field is available in the present method. As a result, both P and SV second harmonics are generated at the cylindrical interface. The numerical results for the directivity patterns of second harmonics are also given. The results show that the directivity patterns depend on the interfacial stiffness. Moreover the relationships between the interfacial stiffness and the ratio of stress in forward direction to backward direction are investigated in order to discuss the interfacial stiffness dependence in detail. The ratio significantly varies with the interfacial stiffness and the relationships are different by the frequency of the incident wave. Due to these characteristics, the ratio of stress in forward direction to backward direction can be useful for the evaluation of the interfacial stiffness. The influence of the ratio of the transverse stiffness to normal stiffness on the ratio of stress is also demonstrated. It is shown that the ratio of the interfacial stiffness has little effect on the ratio of stress.

著者

星野 純輝 祖山 均

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00502-16-00502, 2017 (Released:2017-05-25)

参考文献数

10

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In order to establish a new approach to manufacturing of CaCO3 which can be adapted to structural materials, the formation of CaCO3 using continuous-wave laser has been conducted on austenitic stainless steel JIS SUS316L surface. It has been demonstrated that localized heating by laser irradiation could control the formation. CaCO3 was obtained from heating Ca(HCO3)2. The film thickness of CaCO3 formed at various conditions was measured, therefore it was revealed the effect of various factors on the formation of CaCO3. The higher laser power P, the thicker the film thickness of CaCO3, however, high laser power (1.5 W) decreases the film thickness when laser irradiation is continued for many hours. Changing the distance from condenser lens d to specimen, it can control the film thickness and the width of CaCO3 film without increasing energy. When the velocity of specimen v is 1.0 mm/s, the film thickness is the highest among other velocities and the shape of CaCO3 film is clear. The temperature of Ca(HCO3)2 Tw have not much effect on the film thickness, although the temperature have effect on the width of CaCO3 film. Therefore, CaCO3 film can be formed efficiently by controlling the factors such as laser power. The optimum condition of fabrication of CaCO3 which we inferred from these results was P = 1.0 W, d = 30 mm, v = 0.1 mm/s, Tw = 45 °C, laser irradiation time t = 5 h. This manufacturing have probability to be able to fabricate the structure of CaCO3 flexibly.

著者

太田 高裕 河野 亮 小﨑 貴史

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00451-16-00451, 2017 (Released:2017-05-25)

参考文献数

12

被引用文献数

2

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Peen forming has been widely used in the aerospace industry for forming complex components of large thin wings. The conventional peen forming using spherical shots shows a tendency to form the spherical surface because of its axisymmetric plastic strain. In this study, a new peen forming method using rectangular solid pins is developed. It is possible to produce the different distribution between x direction (short side of pin) plastic strain and z direction (long side of pin) plastic strain. The anisotropic plastic strain distribution causes smaller curvature radius of x direction section than that of z direction section. In order to verify the anisotropic plastic strain distribution in this method, the effects of pin tip shape are analyzed by dynamic explicit finite element method. The ratios of x direction plastic strain to z direction plastic strain increase with decreasing pin tip radius. It is confirmed that anisotropic double-curved surfaces are produced by drop tests using multi- rectangular-solid pins.

著者

大山 慎太郎 梅原 徳次 上坂 裕之 鄧 興瑞 村島 基之 堀江 茂 松山 洋介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.849, pp.16-00378-16-00378, 2017 (Released:2017-05-25)

参考文献数

13

被引用文献数

1

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This paper describes about the effect of drill surface texturing on height of back burr in titanium alloy drilling process with solid lubricating sheet. Titanium alloy is difficult to conduct drilling because titanium alloy is hard and ductile material. And the workers cannot use plenty of liquid coolant for preventing the productivity decline when the work places are above their heads in production fields. Therefore drills are exchanged frequently even though the cost increases. In this study, we measured the cutting force by a loadcell to know the effect of drill surface texturing and solid lubricating sheet on drilling process of work pieces made of Ti-6Al-4V. As the results, drill with rough textured rake surface showed high burr height in exit of Ti-6Al-4V. On the other hand, drill with rough textured flank surface showed low burr height only if drilling with solid lubricating sheet. Moreover, drill with the specific texturing on flank surface by wire electric discharge machining showed low burr height.

著者

梅原 康宏 鴨下 庄吾 小黒 翼 三俣 哲

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.847, pp.16-00523-16-00523, 2017 (Released:2017-03-25)

参考文献数

7

被引用文献数

2

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We have devised a steering system in which the magnetic elastomer is used for the elastic members such as rubber bushings in the axle box suspension of railway vehicles. The magnetic elastomer is composed of magnetic particles and the elastomer such as synthetic rubber. This material is characterized by its hardness variation depending on the magnetic field. The axle box suspension using the magnetic elastomer is capable of varying the longitudinal stiffness. In straight sections, the application of this axle box suspension ensures running stability by increasing the longitudinal stiffness by means of applying a magnetic field. On the other hand, in curve sections, it improves curving performance by decreasing the longitudinal stiffness by means of turning off the magnetic field. We made test pieces towards the development of the magnetic elastomer for the steering bogie. In a characteristic test, we confirmed that the Young's modulus of the magnetic elastomer changes in the range of about five times depending on the presence or absence of the magnetic field. In addition, we simulated the vehicle model by applying the longitudinal stiffness change of the magnetic elastomer to the axle box of the bogie. We confirmed that this axle box was capable of reducing the average of the outer wheel lateral force in the circular curve section compared to that of the normal axle box.

著者

亀谷 均 内村 和弘 樋野 貴規 山根 勁

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.847, pp.16-00493-16-00493, 2017 (Released:2017-03-25)

参考文献数

8

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In general, manual sorting carries out for the quality inspection of corbicula shells prior to shipment. The inspection worker drops each corbicula shells on the concrete floor, and a shell is assessed as good or bad by the sound of collision with floor. The corbicula shell containing mud or nothing is specified as a bad corbicula. This manual sorting process is time consuming and laborious. In addition, this process is often prone to mistakes. In order to overcome the problem of manual sorting, an inspection probe has been developed. The inspection probe assesses a corbicula shell as good or bad by detecting the transmitted light spectra, and it has been tested that the probe can detect good and bad corbicula shells with an accuracy of 100%. Thereafter, a quality sorting device with the inspection probe has been developed for the commercial use. A laboratory based experiments have been conducted first to evaluate the performance of developed quality sorting device. The test results showed that the sorting device can sort shells with an accuracy of about 99%. Subsequently, a comprehensive evaluation experiment have also been carried out, and the experimental results showed that our developed sorting device is able to sort corbicula shells with an accuracy of 98.6%. This results implies that the present quality sorting device is ready to use for commercial sorting of corbicula shells

著者

前田 慎市 青島 亮太 黒澤 哲朗 小原 哲郎

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.846, pp.16-00269-16-00269, 2017 (Released:2017-02-25)

参考文献数

20

被引用文献数

1

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Detonation transition was experimentally investigated using flame jetting through the orifice of a small sub-chamber, which was equipped on the side wall near the closed end of the main channel (square inner closs section, 50 mm on a side) filled with a stoichiometric hydrogen-oxygen mixture at an initial pressure of 80 kPa. The number of sub-chambers and orifice diameters were changed as 1, 2, 4 (called as FJ1, FJ2, FJ4, respectively) and 3, 5, 7 mm, respectively, and the facing flame jets were collided with each other in FJ2 and FJ4. Two regimes of detonation transition were observed: (i) deflagration-to-detonation transition (DDT) accompanied by flame acceleration process and (ii) direction initiation of a detonation near the flame jetting section. The flame propagation distance required for detonation transition was one-half to one-third for regime (i) compared to single-spark ignition without flame jet, and below one-sixth for regime (ii). Except for the case of regime (ii), observed for an orifice diameter of 5 or 7 mm of FJ4, the detonation transition distance had no significant effect on the types of flame jetting and orifice diameters. Time-resolved schlieren recordings showed that the choked jet of combustion products drove the shock wave preceding the flame front, and induced multi-dimensional flame motion and repeated shock-flame interactions in the confinement. These behaviors enhanced flame velocity at the ignition end by a factor of 4 to 7 in FJ1 and FJ2, compared to single-spark ignition. The effect of these enhanced flame velocities on DDT distances was consistent with the semi-empirical model of flame acceleration process in a smooth tube. The schlieren recordings and pressure measurements at the closed end indicated that the possible factors for the initiation of detonation in regime (ii) were the mixing of reacted and unreacted gas induced by the repeated strong shock-flame interaction and the hot spot formed by shock-shock interaction driven by the facing flame jetting.

著者

蓮沼 将太 波田野 明日可 泉 聡志 酒井 信介

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.83, no.846, pp.16-00264-16-00264, 2017 (Released:2017-02-25)

参考文献数

14

被引用文献数

1

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In this study, the effect of machined surface layer on residual stress relaxation was investigated. In previous study, low cycle fatigue strength was affected by residual stress. However, residual stress relaxation was complex because local plastic strain occurred by stress near yield stress. Also, machined surface layer affect the yield stress. Therefore, machined surface layer was modeled using the crystal plasticity model, i.e. plasticity model based on crystallographic deformation mechanics. To describe the microstructure of plastic deformation layer, initial dislocation density and back stress near surface were changed. To describe the microstructure of fine grained layer, grain size near surface was changed. Residual stress relaxation was simulated by crystal plasticity finite element method. Three types of machined surface layers were modeled. Two kind of strain amplitude condition was simulated. In simulation results, local plastic strain was occurred under global elastic condition. Residual stress after cyclic load was different from machined surface conditions under low strain loading. Residual stress was largely relaxed in all cases under high strain loading. Comparing fatigue life of experimental results, simulation results were thought to be valid. Therefore, residual stress relaxation is able to be predicted using this model. Hardening in plastic deformation layer prevents yield by tensile load. However, plastic strain was occurred in plastic deformation under compression load. On the other hand, fine grain layer prevent yield by not only tensile but also compression.

著者

近藤 義広 越田 博之

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.844, pp.16-00173-16-00173, 2016 (Released:2016-12-25)

参考文献数

10

被引用文献数

1

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In order to evaluate the cooling performance of the porous metal fins, both the friction factor and heat transfer coefficient were taken into account. In this study, we compared six porous metal fins and four kinds of heat exchangers made of porous material. Moreover, we proposed a new model which predicts the cooling performance of the porous metal fins. Friction loss factor of porous metal fins became predictable in less than ±10% error by using effective cross-sectional flow area and Ergun coefficient in Forchheimer-extended Darcy model. Heat transfer coefficient of porous metal fins can be predicted within an error of 10% by our model. The predictive model has two assumptions. One is that the perimeter in the porous metal fin per cross-sectional area of porous metal fin is independent of the heights of fins and number of porous cells. Another assumption is that heat transfer coefficient of porous metal fin is also independent of the heights of fins and number of porous cells as long as the velocity is same.

著者

本仲 君子 渡辺 桂吾 前山 祥一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.81, no.825, pp.14-00631-14-00631, 2015 (Released:2015-05-25)

参考文献数

11

被引用文献数

1 2

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Recently, it is expected to develop an autonomous robot working in a living environment. Motion planning is very important for an autonomous mobile robot, but kinematic constraints and dynamic constraints are generally solved separately in conventional motion planning. In this research, a simpler way of deciding the control input for an autonomous mobile robot, which is described by a highly nonlinear model in a multi-dimensional space, is proposed by solving kinematic constraints and dynamic constraints simultaneously, under the kinodynamic motion planning based on a harmonic potential field (HPF). In this paper, a quadrotor that is very attractive as an aerial robot due to its high maneuverability, is assumed to be a controlled object, and it is aimed at guiding the quadrotor to an arbitrary target point while avoiding obstacles. Then, three types of controllers for kinodynamic motion planning based on an HPF, which were developed for point mass control, are extended to be applied to the quadrotor. The extended controllers are compared each other in trajectory, amplitude of attitude, and arrival time through some flight simulations. Moreover, multiple gains included in the proposed controllers are optimized automatically by using genetic algorithm (GA), in order to realize highly accurate control. Flight simulation in an untrained environment, which is different from the environment that the gains were selected by GA, is also conducted, and it is confirmed that the quadrotor can move onto the target point with the same gains while avoiding obstacles.

著者

長山 格

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.838, pp.15-00278-15-00278, 2016 (Released:2016-06-25)

参考文献数

23

---

This paper describes a high performance parallel image retrieval system for mechanical drawings management. The system is designed with PC-cluster that consistes of one master node and eight slave nodes. In order to achieve a higher performance, parallel processing and precise searching process are introduced to the proposed system. The parallel processing uses many rotated templates of a target symbol to perform pattern matching by each slave node. The precise searching is newly designed by analyzing our previous study for image retrieval of mechanical drawings. Object detection in many kind of images continues to be one of the most common application for image processing and understanding. We first discuss some essential issues to be considered conventional object detection with large digital images. Experimental results by using the proposed system are also described. The good performance of the system is shown.

著者

野中 紀彦 岩崎 富生 守谷 浩志 谷江 尚史 池田 靖

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.81, no.824, pp.15-00018-15-00018, 2015 (Released:2015-04-25)

参考文献数

31

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A Kriging-based method for efficiently searching materials was used to select additive elements in lead-free solders that are effective for suppressing the grain-boundary diffusion, which is the cause of smaller breaking elongation than lead-contained solders. By using the idea of the L9-orthogonal-array design methodology, we selected nine combinations of additive elements, and investigated the dependence of diffusion coefficients on four parameters (the atomic radius of the 1st additive, the cohesive energy of the 1st additive, the atomic radius of the 2nd additive, and the cohesive energy of the 2nd additive). The diffusion coefficients were calculated by using molecular-dynamics simulations. The calculation results showed that the diffusion can be suppressed when the atomic radii of the 1st and 2nd additives are close to that of tin (Sn), and when the cohesive energies of the 1st and 2nd additives are smaller than that of tin. According to these conditions, we found that two additives selected from silver (Ag), indium (In), and bismuth (Bi) are effective for suppressing the diffusion and for increasing the breaking elongation. Because these results were confirmed by tensile deformation test, the Kriging-based method is considered to be practical for effectively searching materials.

著者

長山 格

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

2016

---

This paper describes a high performance parallel image retrieval system for mechanical drawings management. The system is designed with PC-cluster that consistes of one master node and eight slave nodes. In order to achieve a higher performance, parallel processing and precise searching process are introduced to the proposed system. The parallel processing uses many rotated templates of a target symbol to perform pattern matching by each slave node. The precise searching is newly designed by analyzing our previous study for image retrieval of mechanical drawings. Object detection in many kind of images continues to be one of the most common application for image processing and understanding. We first discuss some essential issues to be considered conventional object detection with large digital images. Experimental results by using the proposed system are also described. The good performance of the system is shown.

著者

藤川 正毅 石川 清貴 真壁 朝敏 田中 真人 笹川 崇 表 竜二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

2016

被引用文献数

2

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This paper presents a novel Formulated Alpha FEM with deviatoric / volumetric split, which is combination of standard FEM and Node-based Smoothed FEM (NS-FEM), to compute highly accurate deformation in mechanical problems using tetrahedral elements. The essential idea of the method is the use of a deviatoric alpha formulated on basis of the results of cantilever problem, and the volumetric alpha introduced NS-FEM. The features of this proposed method are: 1) immune from volumetric locking, 2) less sensitive to element distortion, and 3) to be carried out with the same preprocessing as standard FEM from user's viewpoint. Several numerical examples show that the present method achieves higher accuracy compared to the standard FEM and Edge-based/NS-FEM which is known to be one of the best S-FEM formulations.

著者

長山 格

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.15-00278, (Released:2016-06-10)

参考文献数

23

---

This paper describes a high performance parallel image retrieval system for mechanical drawings management. The system is designed with PC-cluster that consistes of one master node and eight slave nodes. In order to achieve a higher performance, parallel processing and precise searching process are introduced to the proposed system. The parallel processing uses many rotated templates of a target symbol to perform pattern matching by each slave node. The precise searching is newly designed by analyzing our previous study for image retrieval of mechanical drawings. Object detection in many kind of images continues to be one of the most common application for image processing and understanding. We first discuss some essential issues to be considered conventional object detection with large digital images. Experimental results by using the proposed system are also described. The good performance of the system is shown.

著者

大場 啓介 長嶺 拓夫 森 博輝 佐藤 勇一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.14-00593, (Released:2015-02-24)

参考文献数

8

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This paper describes the investigations of the characteristic about the sound generation of a nose flute experimentally. The nose flute is attached to the upper part of a container. If air is passed to a nose flute, sound will occur. The volume of a container is changed and the generated sound is measured. The natural frequencies of an experimental device are calculated and we confirm that it is in agreement with frequency of sound generated in experiment. We show that nose flute is a unique musical instrument with the point that a nose flute has only an edge part and uses people's mouth for a resonance body part. The frequencies of resonance sound can be calculated from the capacity in a mouth, the thickness and the area of an opening of a nose flute. When people play a nose flute, it is thought that only the first mode of vibration is used.

著者

萩野 直人 吉田 博夫 今田 晴彦

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

pp.15-00596, (Released:2016-04-25)

参考文献数

16

被引用文献数

1

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The self-circulating thermosyphon (SCTS) operates without external pumping power. It is a closed loop of pipe and consists of heater, condenser, heat exchanger and recuperator. In this paper the basic performance of SCTS was examined experimentally under various back ground pressures and power inputs to the heater. Experimental results showed that the stable operation of SCTS was limited by the minimum input power overcoming the total losses of the system and the maximum power within the ability of the condenser. At fixed back ground pressure, mass flow rate and quality of water vapor in heater were confirmed to increase with the power input. As back ground pressure increased, mass flow rate was prone to decline. Those suggest that the main driving force of SCTS is buoyancy force of the vapor. Thermal transport efficiency ranged from 0.4 to 0.9 as far as the present conditions are concerned.

著者

村岡 祥雄 関 研一 西村 秀和

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.835, pp.15-00480-15-00480, 2016 (Released:2016-03-25)

参考文献数

15

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Thermal design of electronic products has become increasingly complicated with leakage current characteristics and their variation of semiconductors. This paper proposes an application of a thermal system model to a production system of electronic products. The thermal system model is developed for architecture design to determine design parameters of modules. The model is described with Systems Modeling Language (SysML) considering interactions among parameters of mechanical structure and electrical components that include semiconductors with temperature-dependent leakage current characteristics. In the system model, constraints of heat generation and heat transfer are described using equations and relation between equations and parameters are clarified in parametric diagram. The system model that is developed at the early stage of product design is used at the beginning of integration, such as receiving inspection. To prevent quality degradation by variation in component characteristics, semiconductor components such as processing units are screened with thermal simulation result before their implementation on Printed Wiring Board (PWB). The simulation result is being referred to temperatures that cause low-temperature burn injury. As a case study, a system model of portable product is developed and demonstrates thermal simulation to determine limitation in large variation in leakage current characteristics to satisfy product thermal quality. To improve yield ratio of the semiconductor components after screening, system models are developed for various products in which same processing units are installed. The system model can be applied for each product changing the design parameters and simulate to determine allowable range of component characteristics keeping the product quality. Implementing a component that causes more leakage effect into a product that has more allowable range, degradation of product quality can be avoid without losing the component yield ratio.

著者

藤川 正毅 石川 清貴 真壁 朝敏 田中 真人 笹川 崇 表 竜二

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

vol.82, no.834, pp.15-00454-15-00454, 2016

被引用文献数

5

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This paper proposes a novel implementation scheme of geometrically nonlinear finite element programs, which automatically compute exact internal force vectors and element stiffness matrices by numerically differentiating a strain energy function at each element. This method can significantly simplify the complex implementation procedure which is often observed in conventional finite element implementations, since it never requires B matrices, stress tensors, and elastic tensors by hand. The proposed method is based on a highly accurate numerical derivatives which use hyper-dual numbers and never suffer from any round-off and truncation errors. Several numerical examples are performed to demonstrate the effectiveness and robustness of the proposed method.

著者

藤川 正毅 石川 清貴 真壁 朝敏 田中 真人 笹川 崇 表 竜二

出版者

The Japan Society of Mechanical Engineers

雑誌

日本機械学会論文集 (ISSN:21879761)

巻号頁・発行日

2016

被引用文献数

5

---

This paper proposes a novel implementation scheme of geometrically nonlinear finite element programs, which automatically compute exact internal force vectors and element stiffness matrices by numerically differentiating a strain energy function at each element. This method can significantly simplify the complex implementation procedure which is often observed in conventional finite element implementations, since it never requires B matrices, stress tensors, and elastic tensors by hand. The proposed method is based on a highly accurate numerical derivatives which use hyper-dual numbers and never suffer from any round-off and truncation errors. Several numerical examples are performed to demonstrate the effectiveness and robustness of the proposed method.