著者

仲町 英治 三木 一生 古川 一憲 武川 雄一 土井 哲平

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.71, no.701, pp.73-79, 2005-01-25

参考文献数

9

被引用文献数

2

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In this paper, a new head injury criterion evaluated by the hydrostatic stress occurred in the head crash phenomenon. In order to obtain the threshold value for brain's organ and tissue, <I>in vitro</I> impact experiments to cultured nerve cells were performed. PC-12 cultured nerve cell was employed to imitate the human's nerve cell. In the experiments, various pressure waves were generated by introducing different heights of dropping weight for impacting. Relationships between peak values of impact compressive and expansive pressure waves and detachment rates and injury rates evaluated by the cell membranes damage were obtained.

著者

中 庸行 磯野 吉正 田中 武司 寺山 暢之

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. A編 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.64, no.620, pp.1061-1068, 1998-04-25

参考文献数

19

被引用文献数

2

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This paper describes the effect of density of Diamond-Like Carbon (DLC) thin film on tribological property. DLC thin films having the density of 1.9-2.5 g/cm<SUP>3</SUP> were prepared on (111) of Silicon surface by the hot cathode PIG Discharge Type Plasma-Enhanced CVD method. Ball on disk friction experiments were carried out using diamond ball. The friction coefficients increased from 0.05 to 0.20 with increasing film density in the density range below 2.185 g/cm<SUP>3</SUP>, but those did not change above 2.185 g/cm<SUP>3</SUP>. The specific wear value also increased with increasing film density. The effect of film density on tribological property between DLC thin film and diamond pin was examined by molecular dynamics simulation. The diamond pin slides to uniaxial direction on DLC thin film having the density 1.5-3.0 g/cm<SUP>3</SUP>. Atoms of DLC thin film having the density of 1.5 g/cm<SUP>3</SUP> were moved most actively. Atomic movement being like to shear deformation was observed during frictional processes. The effect of film density on friction coefficients in MD simulations was similar to that in experiments qualitatively.

著者

東藤 貢 高橋 清 / KAUSH H. Henning

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.64, no.617, pp.36-43, 1998-01-25

参考文献数

13

被引用文献数

2 2

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Mode I fracture behavior of rubber toughened PMMA (RTPMMA) was studied over five decades of displacement rates (10<SUP>-4</SUP>-13 m/s) using a high-speed tensile testing machine. Two kinds of RTPMMA, extruded RTPMMA containing 20 wt.% rubber particles (EM20) and pressed RTPMMA containing 40 wt.% rubber particles (PM40), exhibited different rate dependences of the maximum stress intensity factor K<SUB>1max</SUB> and the maximum energy release rate G<SUB>1max</SUB>. K<SUB>1max</SUB> and G<SUB>1max</SUB> of EM20 decreased rapidly at high rates (1-11 m/s). This suggests that the toughening effect due to rubber blending was dramatically reduced at the high rates. On the other hand, PM40 maintained high K<SUB>1max</SUB> and G<SUB>1max</SUB> values at all rates tested in this study. Thus, PM40 maintained the toughening effect even at high rates up to 13 m/s. For comparison, unmodified PMMA was also examined, and the results showed that K<SUB>1max</SUB>of neat PMMA increased with the increase in displacement rates and G<SUB>1max</SUB> remained constant as the rate increased. Discussion is given on the rate-dependent K<SUB>1max</SUB> and G<SUB>1max</SUB> values, taking (K<SUB>1max</SUB>)<SUP>2</SUP>/G<SUB>1max</SUB>into account. The fracture surface morphology of the specimens is also discussed.

著者

陳 錦祥 橋本 良作 福山 佳孝 松下 政裕 小河 昭紀 大沢 真人 横川 忠晴 厚田 広史

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. A編 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.72, no.716, pp.432-437, 2006-04-25

参考文献数

19

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The effects of crystal orientation (&theta;) on the structural strength of single crystal trubine vanes and blades calculated with the finite element method (FEM) are discussed in this paper. TMS-75, a 3<SUP>rd</SUP> generation single-crystal Ni-base superalloy, is chosen as the model material for turbine vanes and blades. It became clear that, (1) the elastic constant matrix changes were equivalence for each of three coordinate due to the orientation variation (0&deg;<&theta;<90&deg;), and the strength of the turbine vane and blade were strongly related to &theta;, and also depended on the load and model shape. (2) The strength dependence of the turbine vane on the crystal orientation was depended on coordinate plane : there are lower Mises stress in XY plane and maximum Mises stress in near the &theta;=45&deg;at both YZ and ZX Planes. (3) In the case of a blade, the influence is similar to the vane on blade tip, but the converse holds for the blade root. It is clear that the creep rupture time can be extended, when the <100> crystallographic axes is the Y or X axis of the blade under higher revolution speed.

著者

竹田 憲生

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.73, no.733, pp.105-112, 2007-09-25

参考文献数

12

被引用文献数

1 3

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This paper verifies the response surfaces of artificial neural networks (NN) learned by using a method based on Bayesian inference. Mackay showed that the Bayesian method due to Gull and Skilling can be applied to regularization for NN. However, generalization ability has not been verified sufficiently for the NN response surface regularized by using the Bayesian method. If the NN response surface has good generalization ability, it can be used in the optimization process of response surface methodology (RSM) NN therefore was learned by using the Bayesian method to investigate generalization ability. We tried three rules for updating the regularizing constants in an objective function minimized during NN learning. All of the update rules were derived from the Bayesian method. As a result, the response surface of NN had good generalization ability, with the exception of one update rule. The poor update rule failed to determine the regularizing constants. This tendency for the update rules was recognized regardless of response surface geometry. After we selected a superior update rule, the NN response surface by using the Bayesian method was applied to an optimization problem. The response surface didn't fit noises included in teacher data, and consequently, it was effectively used to reach a solution. Finally, we concluded that the NN learned by using the Bayesian method can be used as the response surface in the process of RSM.

著者

尾田 十八 坂本 二郎 坂野 憲一

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.71, no.701, pp.89-94, 2005-01-25

参考文献数

6

被引用文献数

2

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A woodpecker strikes its beak toward a tree repeatedly. But, the damage of brain or the brain concussion doesn't occur by this action. Human cannot strike strongly the head without the damage of a brain. Therefore, It is predicted that the brain of a woodpecker is protected from the shock by some methods and that the woodpecker has the original mechanism to absorb a shock. In this study, the endoskeltal structure, especially head part structure of woodpecker is dissected and the impact-proof system is analyzed by FEM and model experiment. From the results, it is obvious that the woodpecker has the original impact-proof system as the unique states of hyoid bone, skull, tissue and brain. Moreover it is considered that woodpecker has the advanced impact-proof system relating with not only the head part but also with the whole body.

著者

菊池 正紀 和田 義孝 高橋 真史

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. A編 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.74, no.742, pp.812-818, 2008-06-25

参考文献数

15

被引用文献数

10

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Fatigue crack growth under mixed mode loading conditions is simulated using Superimposed-FEM (S-FEM). By using S-FEM technique, only local mesh should be re-meshed and it becomes easy to simulate crack growth. By combining with re-meshing technique, local mesh is re-meshed automatically, and curved crack path is modeled easily. At first, slant crack problem is solved. It is shown that results agree with conventional solutions, and verified the availability of this technique.Then two-crack problems are solved in several cases by changing each crack location. Stress intensity factors are evaluated and interaction effect between two cracks is discussed. Results are compared with crack coalescence criteria, and it is verified that these criteria are reasonable ones.

著者

櫻井 俊彰 多田 雅彦 石井 英章 野原 哲男 星野 裕昭 高橋 邦弘

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.73, no.726, pp.195-200, 2007-02-25

参考文献数

4

被引用文献数

2 3

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The concept of the parameter U* has been introduced by the authors to express load transfer in structures. In this paper, an extended definition of U* is introduced for structures under multiple loadings. The new expression of U* with the matrix formulation of internal stiffness can effectively be applied to an efficient calculation of U* distribution. Examples of U* calculation for an actual truck cab structure under multiple loading are demonstrated. Calculation results of U* for cases under multiple loading condition and single loading condition are compared, and the applicability of St. Venant's principle concerning U* distribution is discussed.

著者

川節 望 新藤 健太郎 田北 勝彦 増山 不二光

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 = Transactions of the Japan Society of Mechanical Engineers. A (ISSN:03875008)

巻号頁・発行日

vol.74, no.741, pp.669-677, 2008-05-25

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Glass Fiber Reinforced Plastics (GFRP) have been applied to products such as building components and various structural materials in industrial plants due to their excellent lightness and corrosion resistance, as well as weather resistance since the 1980's. Use of GFRP for large-scaled components and/or components with repetitive load has increasingly widespread in recent years, and both tensile and compressive properties have thus become important. Reinforcing laminate for GFRP has been mainly woven fabric such as glass woven roving due to its easy handling. However, its fiber winding and gap occurrence have been problems to be solved. In the recent years, new fiber fabrics for reinforcement have come on the market owing to rapid development of weaving machine, and one of the new fabrics is the stitched fabric. This glass fiber stitched fabric has been increasingly developed in Europe and all over the world for over ten years, and in Japan, has extended its application for ship for about ten years. This study investigates and examines GFRP reinforced with unidirectional glass fiber stitched fabric, in respects of the effect of fiber laminated constitution, fiber content and fiber diameter on tensile and compressive properties. Additionally, this study also examines relevance between weaving patter of fiber and strength property by comparing 0 degree/ 90 degree stitched fabric with GFRP with general woven roving.