著者

北野 誠 西村 朝雄 河合 末男

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.57, no.538, pp.1398-1405, 1991-06-25 (Released:2008-02-21)

参考文献数

5

被引用文献数

2 1

---

The plastic packages of ICs have been changing from insertion types to surface mounted types. Reflow soldering is used for surface mounted ICs onto printed circuit boards. During this process, packages are heated to above 200°C. If the encapsulant absorbs moisture, package cracking may occur during the reflow soldering. It is known that the cracks are caused by vapor pressure generated inside the packages, causing excessive stress in the plastic. In the former report, moisture diffusion analysis in the plastic was performed and vapor pressure could be obtained. Since the edge tip of the chip pad where package cracking occurs is a singular point within the elastic stress field, strength evaluation for package cracking is not established. In this study, the quantitative strength evaluation of the plastic is investigated by using the stress singularity theory.

著者

臺丸谷 政志 小林 秀敏

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.77, no.776, pp.638-646, 2011

被引用文献数

1

---

The Japanese sword is a weapon peculiar to Japan. The Japanese sword is interesting not only from the viewpoint of traditional crafts of arts, but also from the aspect of modern science and technology because the way of making and its functionality as a weapon are really consistent with science. The present study is concerned with the connection between <i>tohshin</i> (blade) and <i>tsuka</i> (hilt) of the sword. Only one <i>mekugi-take</i> (retaining peg made of bamboo) with about 5mm in diameter holds <i>Nakago</i> (tang) in the hilt. However the slender <i>mekugi</i> might not be broken, even though in the case of violent sword-fighting. This fact has been historically demonstrated in many battles by Japanese swords. In this study, using a <i>Tachi</i> being the typical Japanese sword, it is examined theoretically and experimentally from the viewpoint of impact engineering why a <i>mekugi</i> used in Japanese swords might not be broken. As a result, it is made clear that such a strong force as breaking <i>mekugi-take</i> does not act on it, because of the location of <i>mekugi-ana</i> (a hole for <i>mekugi</i>) in the tang, which has been made by the traditional code of sword-smiths.

著者

三戸 暁 町田 邦郎

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.45, no.394, pp.559-566, 1979-06-25 (Released:2008-02-21)

参考文献数

11

---

伸びの異なる2種類の金属繊維を用いて,エポキシ樹脂を強化した複合材料を試作し,その常温クリープ挙動を調べた.その結果,伸びの小さいタングステン繊維を含む複合材料は,みかけ上遷移,定常,加速クリープを示し,繊維,母材ともに破断したが,体積率の小さな試験片ではタングステン繊維にマルチプルネッキングが生じた.一方,伸び大きいステンレス繊維を含む複合材料は,対数クリープだけを示し,この傾向は高体積率,低応力になるほど著しく,また,クリープ破断は母材だけでおこり,繊維は母材から引き抜けた.

著者

岩本 正実 田中 英一 伝田 耕平 山本 創太

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.71, no.705, pp.872-879, 2005-05-25 (Released:2011-03-02)

参考文献数

19

---

An anisotropic inelastic constitutive model of cortical bone was formulated to predict deformation and failure behavior in traffic accidents or falling by utilizing the framework of viscoplasticity and damage mechanics. The model can represent characteristic features of cortical bone, such as anisotropic elastic coefficients with strain rate dependency, viscoplasticity with strength anisotropy as well as strength asymmetry of tension and compression. The damage evolution equation also enables us to predict bone failure with rate dependency. Experimental data of uniaxial compressive or tensile loading tests of human cortical bone at various strain rates were used to validate the proposed model. Predicted stress-strain curves and failure points agreed well with those of experimental data at wide range of strain rates. This shows the present model can be used to predict bone failure in various impact simulations of traffic accidents or falling.

著者

河村 勇太 苗村 潔

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.75, no.756, pp.1124-1126, 2009-08-25 (Released:2017-06-09)

参考文献数

4

被引用文献数

1 1

---

The colonoscope is widely employed for cure of a large intestinal disease. However, the medical accidents such as large intestines perforation by an immature doctor is still increase, because insertion operation of the colonoscope is highly skillful. To solve this problem, We think that development of a training device is effective. We aim to verify whether the porcine large intestines are able to become substitute as the human large intestines. The tensile experiment and the punch experiment were conducted on 243 samples of 14 pigs. The tensile experiment showed that stress at break was 0.20±0.08MPa, and strain at break was 0.51±0.24, and Young's modulus was 0.42±0.22MPa, and the poisson ratio was 0.71±0.22. Imitative endoscope extended the porcine large intestines forward perpendicular direction from the surface. The results showed the porcine large intestines were perforated by 11.9±2.8N. All results showed that porcine large intestines were able to become substitute of human large intestines.

著者

村上 敬宜 金崎 俊彦 福島 良博 田中 裕之 戸室 仁一 久保山 孝治 松栄 雅樹 伊藤 義雄 安藤 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 A編 (ISSN:03875008)

巻号頁・発行日

vol.75, no.749, pp.93-102, 2009-01-25 (Released:2017-06-09)

参考文献数

6

被引用文献数

4 7

---

The fatigue failure analysis of SUS316L flexible hose of the hydrogen station which was demonstrated during EXPO 2005 in Nagoya was carried out. The fatigue fracture surface where hydrogen leakage was detected showed clear striations which revealed a unique evidence of hydrogen effect on the ratio of striation height and spacing. The number of striations observed on the leakage fracture surface was 270. Considering that the number of hydrogen supply to the fuel cell buses was 280, it can be concluded that the fatigue fracture process during the demonstration is completely controlled by microplasticity resulting ductile fracture contrary to the conventional concept expressed with a term of decohesion or hydrogen embrittlement. The striation data were used to make the fatigue crack growth rate equation which was applied to the life prediction and structural integrity assessment for a new hydrogen station. The fatigue crack growth data showed the evidence of a strong frequency effect of fatigue crack growth rate of SUS316L used in the hydrogen environment with 8 minutes hydrogen supply time at the hydrogen station.

著者

酒井 譲 山下 彰彦

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.67, no.659, pp.1093-1102, 2001-07-25 (Released:2008-02-21)

参考文献数

12

被引用文献数

11 7

---

As a meshless numerical analysis, particle methods are considered promising in the filed of fluid dynamics and structural analyses. SPH (Smoothed Particle Hydrodynamics), which has been mainly applied to super fast impact or collision problems, is expected to be a more powerful tool for general structural problems such as large deformation and general 3-dim structural problems of complex geometrical objects. However, the fundamental characteristics (accuracy and convergence of solution, effects of time increment and artificial viscosity, etc) of particle methods have not been clarified at all, which causes the fatal limitation of this method. This paper discussed the several numerical properties of SPH by comparing FEM results. It is shown that structural analysis by particle method (SPH) has relatively good accuracy, as well as good numerical convergence and stability in comparison with traditional method (finite element method) and is expected to be a sophisticated tool for a meshless structural analysis.

著者

中山 昇 望月 隆介 澤本 一樹

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.79, no.802, pp.827-837, 2013

被引用文献数

2

---

Porous materials have attracted attention because they exhibit a wide range of useful properties. They are mainly manufactured using either a precursor or a melting method. However, the processes involved are complicated because of the need for a primary extrusion step and the addition of a pore-forming agent. Also, because of the large amount of energy required for the sintering step, these methods represent a large environmental burden. To solve this problem, the present study focused on the formation of solidified porous aluminum by a reaction between pure aluminum powder and pure water, without the need for sintering. The effect of the formation temperature was investigated by measuring the amount of hydrogen released during the reaction, and the density and microstructure of the final materials. X-ray diffraction measurements and compression tests were also carried out. The results of the microstructural observations and X-ray diffraction measurements indicated that, during the reaction, a bayerite layer was formed on the surface of the powder particles. With increasing temperature, the reaction was found to start more quickly and more hydrogen was released. Furthermore, from the compression tests, the initial maximum stress, the plateau stress and the absorbed energy decreased with increasing formation temperature. The results of the present study indicated that it was possible to form highly porous aluminum using the proposed method.

著者

井上 裕嗣 岸本 喜久雄 中西 智明 渋谷 壽一

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.61, no.581, pp.153-160, 1995-01-25 (Released:2008-02-21)

参考文献数

17

被引用文献数

5 6

---

The wavelet transform is applied to time-frequency analysis of dispersive stress waves. The Gabor function is adopted as the analyzing wavelet. The magnitude of the wavelet transform of wave data takes its maximum value at the time when the stress wave reaches the observation point with its group velocity at each frequency. An experiment on the flexural wave in a beam shows that the dispersion relation for the group velocity can be accurately identified by the wavelet transform of measured data. In addition, the application of the wavelet transform to ultrasonic testing of a polymer alloy shows that changes in velocity and attenuation coefficient due to mechanical damaging can be evaluated at each frequency. These results suggests that the wavelet transform has potential ability to present more detailed evaluation of material damages.

著者

金 敏健 山田 邦博 国尾 武

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.51, no.465, pp.1304-1310, 1985

---

共析鋼に脱炭処理を施すことによりフェライトが種々混在する試験片を作製し, 耐久限度の大小に及ぼす限界停留き裂寸法l<SUB>c</SUB>とフェライト体積分率V<SUB>fF</SUB>の関係を調べるとともに, セメンタイトラメラ間隔の変化が耐久限度に及ぼす影響についても検討を加え, 以下に述べる結論を得た. 耐久限度の大小は, l<SUB>c</SUB>がV<SUB>fF</SUB>の減少とともに減少するという現象を通じてV<SUB>fF</SUB>と密接に関連する. また, 耐久限度σ<SUB>woとl<SUB>c</SUB>との間にはσ<SUP>m</SUP><SUB><</SUB>wo</SUB>l<SUB>c</SUB>=Cとなる関係が成立する.

著者

尾崎 公一 福田 忠生 西 亮 椎森 康雄 早川 悌二

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.73, no.726, pp.279-284, 2007-02-25 (Released:2011-03-02)

参考文献数

4

被引用文献数

1

---

In order to investigate the flow of molten metal in a cavity of a die, experimental simulation was carried out by using water flow model. The experimental cavity was constructed of a backward step configuration for test zone, in which flow behavior and air exhaust process from the cavity were investigated. With rib material installed down the step, its effect on air exhaust promotion was examined for various flow velocities. The main results obtained are as follows : Air exhaust from the cavity is remarkably promoted by installation of rib because the strong turbulence around the rejoining potion of two different flows, which are separated by the rib at the upstream, broke rapidly the trapped air into small bubbles. The time taken to complete air exhaust process is in inverse proportion to the flow velocity in the high velocity region, while it is proportion to the flow velocity to the -2.27th power in the low velocity region.

著者

秋庭 義明 木村 英彦 鶴 尋貴 中村 亜有子

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.74, no.742, pp.879-884, 2008-06-25 (Released:2011-03-02)

参考文献数

18

被引用文献数

1

---

Fatigue test system for thin sheets was constructed using an ultrasonic fatigue testing machine. Specimens were fixed at the location where the displacement amplitude became the maximum. The specimen was fatigued under full-reverse bending. Displacement at a fixed edge of the specimen and the deflection of the specimen were measured with a laser displacement gage during fatigue tests. Modal analysis was carried out to determine the dimensions of the specimen and to calculate the applied stress on the basis of the flexural displacement amplitude. The maximum stress was observed on the free side edge near the fixed edge. Two kinds of martensitic stainless steel sheets, SUS301-CSPH and SUS632J1-CSP, were fatigued with the fatigue test system. The thickness of the specimen was 83 and 106μm, respectively. The 3rd vibration mode was selected for fatigue tests. The fatigue cracks initiated from the free side edge of the specimen. For the case of shorter fatigue life, fatigue strength for both stainless steels were almost identical. On the other hand, for longer fatigue life, fatigue strength of SUS632J1 is higher than that of SUS301.

著者

越智 保雄 佐々木 茂美

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.47, no.417, pp.483-491, 1981

被引用文献数

1 2

---

平滑丸棒試験片を用いて応力制御の引張圧縮疲労試験を行なった. 初期段階のΔεpやH<SUB>V</SUB>の増加は転移密度の増加に依存している. この段階は局部的な疲労降伏域が試験片全体に広がる過程である. 中期段階は繰返しによる動的快復の過程であって, 自由転移の移動を規制するセル構造(σ<SUB>a</SUB>大)やループパッチ組織(σ<SUB>a</SUB>小)間の大きさの減少がΔεpの減少を支配している. 初期から中期段階へのせん移は, 疲労すべり帯がなだれ的に発生するためである.

著者

清水 理能 五嶋 孝仁 内山 隆嗣 石原 外美

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.71, no.711, pp.1546-1553, 2005-11-25 (Released:2011-03-02)

参考文献数

16

---

This paper considered three dimensional internal inclined crack growth behaviors due to repeated rolling thermoelastic contact. In this analysis, crack is modeled as an internal inclined planar crack in a three dimensional half-space. Rolling contact is simulated as a long and narrow distributed load with both normal and shear components moving with constant velocity. In comparing the shearing force with the frictional force of crack surface, the phenomenon of stick and slip were considered. At first, stress intensity factors along the crack contour are analyzed using high carbon chromium bearing steels. Next, numerial results of crack growth contours are given based on a modified Paris power low. And fatigue life is estimated by maximum crack growth. The shapes of crack contour and fatigue life are calculated under various conditions, which change sliding ratio, frictional coefficient, angle of inclined crack and friction coefficient of crack surface. As results, when the friction of crack surface is large, the crack progresses greatly in the direction at no friction of crack.

著者

鈴木 新一 森田 康之 坂上 賢一

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.67, no.655, pp.432-439, 2001-03-25 (Released:2008-02-21)

参考文献数

24

被引用文献数

3 4

---

High-speed holographic microscopy is applied to take successive microscopic photographs of a fast propagating crack at bifurcation. The crack speed is about 650 m/s. From the photographs, crack opening displacements (CODs) of the mother crack and two bifurcated branches are measured along the crack. A specimen with a notch is also made, where the notch has the bifurcated notch tip same as the bifurcated fast propagating crack. Opening displacement of the notch is measured by Moire interferometry under static loading condition. The measurement results show that the opening displacements of both the mother crack of the bifurcated fast propagating crack and the mother notch of the bifurcated notch are proportional to square root of the distance r from the crack or the notch tip. The opening displacements of the two bifurcated branches of the notch are also proportional to √(r). But the CODs of the bifurcated branches of the fast propagating crack are not always proportional to √(r).

著者

坂 真澄 巨 陽

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.65, no.639, pp.2193-2198, 1999-11-25 (Released:2008-02-21)

参考文献数

24

著者

平島 健一 杉坂 憲明

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.60, no.575, pp.1557-1563, 1994-07-25 (Released:2008-02-21)

参考文献数

4

被引用文献数

1 5

---

This paper presents a unified analysis of isotropic out-of-plane shear problems containing two circular elantic inclusions and shows the analytical solutions. The applied forces considered in this paper are longitudinal shear stress at infinity, concentrated force, screw dislocation, dipole force, dipole dislocation and distributed forces, at arbitrary positions. The analysis is based on the complex variable method using the Mobius transformations by Honein and Herrman. Several numerical examples are given by graphical representations.

著者

佐脇 豊 伏谷 裕士 徳田 正孝 八木 一夫 稲葉 忠司 関岡 清次 中野 赳

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.63, no.611, pp.1533-1538, 1997-07-25 (Released:2008-02-21)

参考文献数

19

被引用文献数

2 3 8

---

Stress distributions in a canine left ventricular wall are simulated during one cardiac cycle by employing 3-dimensional finite element models developed in order to estimate the functions of the left ventricle. The appropriateness of the numerical simulator is examined by comparing the pressure volume relationships of the left ventricle computed by the present system with those obtained by the corresponding canine experiments. The initial geometry of the left ventricle is assumed to be a prolate spheroid in order to facilitate easy estimation of the complex computed numerical results. It is recognized that the distributions of the wall stress, e.g., the circumferential stress, near the equatorial surface are quite different from those of the thick cylinder subjected to the internal pressure and that the magnitudes and the directions of the principal stresses are closely related to both the contractility and the orientation of the myocardial muscle fiber.

著者

森本 吉春 瀬口 靖幸 東 利彦

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.54, no.504, pp.1546-1552, 1988

被引用文献数

5 10

---

By shifting the discrete Fourier spectrum of the image of a deformed grating, we can obtain "the complex moire pattern". Strain distribution is given as the derivative of the argument of the complex moire pattern. The analysis is completely automatized by introducing the digital image processing. All of the laborious and subjective procedures reguired in conventional analysis such as fringe sign determination, fringe ordering, and fringe interpolation are completely eliminated and objective, fast and accurate analysis can be made.

著者

尾田 十八 / 齊藤 誠 Makoto SAITO

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 A編 (ISSN:03875008)

巻号頁・発行日

vol.67, no.653, pp.121-126, 2001-01-25 (Released:2008-02-21)

参考文献数

8

被引用文献数

4 3

---

Lsystem (LS) is a technique expressing a formation algorithm creating the various shape patterns by the simple rules. Using LS, the complex branch phenomena of plants could be described by simple rules. This paper has tried the methodology to apply LS to the structural design. This methodology grows up the structure as if plants grow up, and produces the optimum structure that is appropiate for the design purpose. It is difficult to acquire LS rules for the optimum structure because the rules have many degrees of freedom. Therefore, this paper proposes an idea that evolves LS rules using Genetic Algorithms (GA) . The methodology is called as an evolutionary LS (ELS) . Using the methodology, the design problems to decide optimum distribution of material and plate thickness are solved.