著者

深沢 剛司 岡村 茂樹 山本 智彦 川崎 信史 稲葉 学 杣木 孝裕 鮫島 祐介 正木 信男

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.17-00050-17-00050, 2017 (Released:2017-08-25)

参考文献数

17

被引用文献数

2

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This paper describes design formulas and creep characteristics for thick rubber bearing applied to the Sodium-cooled Fast Reactor, which are based on the static loading test and creep test using scale models. The thick rubber bearing, which has a rubber layer roughly two times thicker in comparison with conventional rubber bearings, has been developed by the authors to ensure seismic safety margins for components by reducing the seismic response for the reactor building in the horizontal direction and vertical direction. The static loading tests using a scale model with parameter of first shape factor were conducted to investigate the applicability of proposed design formulas. Moreover, an estimation of creep characteristics due to aging is important issue because the rubber layer of thick rubber bearing which satisfies the design requirement for SFR is larger than conventional rubber layer. The creep test was preformed to estimate the creep characteristics using a scale model. From the above results, the thick rubber bearing is sufficiently rational for use as isolation system for SFR.

著者

廣明 慶一 河合 伸人 渡辺 昌宏

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.852, pp.17-00025-17-00025, 2017 (Released:2017-08-25)

参考文献数

20

被引用文献数

2

---

This paper presents a three dimensional flutter analysis of slender webs under tension in cross flow. In the flutter analysis, Doublet-point method based on the unsteady lifting surface theory is used to calculate unsteady fluid force acting on the web surface. The equation of motion of the web under tension is derived by using the finite element method. Flutter velocity, frequency and mode are predicted through the root locus of the flutter determinant of the system with changing flow velocity. The theoretical results are compared to experimental results to confirm validity. Moreover, the local work done by the fluid force acting on the web surface is calculated, and instability mechanism is discussed. Lastly, unified empirical equation of flutter velocities for several parameters of webs is proposed.

著者

山本 真 山本 忠 西山 修二

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.83, no.852, pp.17-00006-17-00006, 2017 (Released:2017-08-25)

参考文献数

26

被引用文献数

2

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This paper presents theoretical research on an optimum transition curve with smoothly changing curvature using a multiple clothoid curve for improving the occupant ride comfort of automobiles. At the connecting points between an inlet straight line and a circular arc, or between a circular arc and an outlet straight line, vehicles cannot run smoothly owing to the discontinuity of curvature. Especially, the vehicles equipped with a driving support device which assists driver's steering operation or performs steering operation instead of a driver will increase both unstable movement of vehicle and discomforts of occupant. Moreover, the discontinuity of curvature in the connecting points makes the control of advanced accuracy of apparatus difficult. In order to solve such problems, three dimensional vehicle occupant model which is 21 degrees of freedom is assembled, and the multiple clothoid curve is proposed as a new transition curve. The validity of the multiple clothoid curve is shown as compared with the case where it is interpolated by a single clothoid curve or by a non-interpolation. It was found that the influence of the multiple clothoid curve on vehicle movement and ride comfort is superior to those of the single clothoid curve or the non-interpolation. Some results are presented in the form of parametric plots.

著者

立畠 健一 植田 好雄 劉 棟博 藤井 文武

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.16-00462-16-00462, 2017 (Released:2017-08-25)

参考文献数

15

被引用文献数

1

---

This paper discloses the development of the improved Bouc-Wen model which captures the behavior of the rate dependent hysteresis of a piezoelectric actuator. The basic form of the Bouc-Wen model only exhibits symmetric hysteresis loop for a sinusoidal input with no DC offset, whereas the real world bi-morph type actuator occasionally exhibits asymmetric loop for the same stimuli. The present works also proposes the integration of the FIR filter to the model to capture phase lag caused by the structural oscillation of the actuator. Comparison of the modeling accuracy has been given with our recent work of adaptive Preisach model. The result shows that accuracy of the two models are almost the same but the intrinsic difference lies in the number of parameters to be determined to form a computable model: the proposed model has only 25 parameters whereas the adaptive Preisach model includes 5050 discretized distribution function values to establish a single model.

著者

末永 陽介 柳岡 英樹 菊池 護 佐々木 駿

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.852, pp.17-00160-17-00160, 2017 (Released:2017-08-25)

参考文献数

19

被引用文献数

1

---

Experimental study was performed to reveal the response characteristics of a stretched cylindrical diffusion flame to sinusoidal oscillation of air flow velocity. The cylindrical flame used in this study has a convex curvature with respect to air stream and is formed in air stream. The fuel is methane, diluted with nitrogen, and the oxidizer is air. Oscillation frequency f is varied from 5 Hz to 250 Hz. Velocity at the outlet of air supplying nozzle was changed sinusoidally with four speakers. Velocity at the fuel nozzle outlet was kept constant. The air velocity at the nozzle outlet is measured using particle image velocimetry. Flame radius rf, flame thickness δ, and flame luminosity Lf are obtained by using high speed video camera. Results are summarized as follows: Though fluctuation amplitude of the velocity gradient of air stream Δga is constant with increasing f, that of the fuel stream Δgf increases. The fluctuation amplitude of rf varies to quasi-steady at low frequency, while the fluctuation amplitude is reduced with increasing f. Lf does not respond to quasi-steady at low frequency. The fluctuation amplitude of Lf has maximum value at 50 Hz and is larger than that for the steady flame corresponding to the velocity fluctuation. It is considered that this complex change of the flame luminosity with respect to f is related to δ/rf which is associated with the flame curvature effect, ga which affects the flame stretch effect, and gf which impacts fuel transport.

著者

竹内 誠一 岡本 達幸

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.852, pp.17-00041-17-00041, 2017 (Released:2017-08-25)

参考文献数

29

被引用文献数

2

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Theoretical examinations based on absorption line databases were carried out about the influence of turbulence-radiation interaction on the radiative heat transfer arriving at the wall of large-scale industrial furnaces, where the re-absorption of radiative energy by combustion gas on its path toward objects to be heated cannot be neglected. In this study, the efficient and accurate calculation method for non-gray analysis and the effective method for handling turbulent fluctuations of radiation and absorption proposed in our previous paper were coupled. Combining the above coupled method and a governing equation solver for obtaining the spatial distribution of time-averaged values of temperature, concentration, velocity and so on, the heat transfer including radiation in large-scale industrial furnaces enveloping turbulent flames was able to be evaluated with sufficient accuracy equivalent to Line-by-Line analysis and with feasible calculation load. By applying this calculation technique to large-scale furnaces, it was found that negligence of turbulent fluctuation in numerical simulation gives rise to obvious change in heat flux distribution on the side wall and in the spatial distribution of time averaged temperature. In addition, change in the total amount of radiative energy arriving at side wall caused by negligence of turbulent fluctuations is fairly small compared with change observed in the case of a typical optical path indicated in our previous report.

著者

前田 慎市 及川 陽介 星野 隆介 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.852, pp.17-00039-17-00039, 2017 (Released:2017-08-25)

参考文献数

10

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A detonation wave propagating in a straight tube (detonation tube) was reflected off the end wall of the tube, and the pressure profile produced by the propagation of the reflected shock wave was experimentally investigated. The detonation wave was initiated at the opposite end of the reflection end, and two ignition conditions were tested. First, ignition at the closed end of the tube (called as “closed ignition end condition”), where the fluid motion was negligible, was evaluated. Second, ignition at the open end of the tube (called as “opened ignition end condition”), where the burned gas flowed toward the vacuum tank attached to the detonation tube, was evaluated. Karnesky et al. (2013) suggested the empirical model in order to represent the pressure profile near the reflection end in the closed ignition end condition. In this paper, the empirical model of Karnesky et al. was modified in order to represent the pressure profile in the opened ignition end condition, and the effect of two ignition conditions on the pressure profiles was discussed. In these models, the pressure profile at the reflection end was empirically formulated by using two empirical parameters, and a uniform pressure distribution between the reflected shock wave and the reflection end was assumed. In this paper, the empirical parameters were normalized by the characteristic parameters for the propagating reflected shock wave. These parameters expressed the conditions of the combustible mixture and the length of the detonation tube. In the opened ignition end condition, the model well represented the measured pressure profile created by the propagating detonation wave and reflected shock wave in the entire length of the detonation tube because the rarefaction wave existed in the entire region behind the detonation wave, and the pressure behind the reflected shock wave had an approximately uniform distribution. Conversely, the model was applicable for a limited duration for the closed ignition end condition because a pressure gradient gradually developed behind the reflected shock wave when the reflected shock wave began to propagate in the plateau region behind the rarefaction wave.

著者

楠山 純平 本多 歩 岩橋 伸太郎 北嶋 孝之 由井 明紀 伊東 利洋 Lu X. Slocum A. H.

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.852, pp.17-00102-17-00102, 2017 (Released:2017-08-25)

参考文献数

23

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Si wafer diameter tends to be increased from 300 mm to 450 mm in order to increase semiconductor device productivity. To this end, the authors developed a rotary grinding machine with high stiffness, equipped with water hydrostatic bearings. This grinding spindle is designed to govern infeed motion of the grinding wheel. This study investigates the basic design and performance of the grinding spindle system. This system itself is composed of a constant pressure water hydrostatic bearing as a radial bearing and a magnetic actuator as a thrust bearing. The magnetic actuator combine the infeed device and the thrust bearing. The measured results show that the static stiffness, Ks, is 1.06 kN/μm, the natural frequency is 353 Hz, and the positioning accuracy is 0.2 μm. These results meet the performance requirements necessary to grind φ450 mm Si wafer.

著者

黒田 雅利 釜谷 昌幸 山田 輝明 秋田 貢一

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.83, no.852, pp.17-00072-17-00072, 2017 (Released:2017-08-25)

参考文献数

13

---

In order to assess the fatigue damage of austenitic stainless steels by electron backscatter diffraction (EBSD) method more simply and easily, it should be more preferable to use a commercially available general-purpose EBSD analysis software rather than to employ an in-house developed EBSD analysis programme. In the present study, EBSD measurement was performed for Type 316 austenitic stainless steels subjected to cyclic loading, and the applicability of the EBSD parameter relevant to the pattern quality, which could be obtained by the commercial software, to the fatigue damage assessment was discussed by comparing the other EBSD parameter of the averaged local misorientation (Mave), which could be calculated by the in-house developed programme. As a result, the EBSD parameter relevant to the pattern quality, which signified the full width at half maximum (FWHM) of the histogram distribution of the image quality (IQ), was saturated at the beginning stage of the fatigue cycles, while Mave was increased monotonically with the cycles. This suggested that the FWHM of IQ could be useful to detect the initial stage of the fatigue damage, while Mave was suitable for the quantitative evaluation of the fatigue damage. XRD measurement was also carried out for the same samples employed in the EBSD measurement, and the XRD data was compared with the EBSD data to discuss the crystallographic mechanism of the change in the FWHM of IQ. As a result, it was found that the FWHM of the (111) XRD peak correlated well with the FWHM of IQ. Because the (111) plane in fcc metal such as austenitic stainless steel was most preferable for slip system, this implied that the change in the distribution of the pattern quality generated by the fatigue loading could be due to the slip deformation.

著者

真鍋 健一 小林 直矢 尾崎 純一 筒井 喜平

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.852, pp.16-00586-16-00586, 2017 (Released:2017-08-25)

参考文献数

24

被引用文献数

1

---

A new finite element model of textile green composites is proposed to simulate thermoforming process in this study. The model is assembled with actual configuration of the green composites and the interface between yarn and matrix has certain GAP. The mechanical behavior of yarn was considered by using truss element. To verify these models, deep drawing tests were performed with experiment. As a result, orientation of yarn and thickness of drawn cup agreed with experiment well. After this process, strength of drawn cup was evaluated with compression test in both finite element method (FEM) and experiment. In FEM, to remove GAP between yarn and matrix, tied contact method that adjust the unconformity of mesh was used. The deformation behavior of the drawn cup agreed with experiment. The effectiveness of thermoforming process to design products with FEM was verified.

著者

野間口 大 中切 拓 藤田 喜久雄

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.17-00122, (Released:2017-09-19)

参考文献数

22

被引用文献数

4

---

Generation of new concepts in product design process serves as driving force of innovation. While many methods have been proposed for supporting design concept generation, it has rarely been supported in a systematic way, because its process is done in designer's implicit thought, and therefore, it is difficult to explicitly formalize the process. This paper proposes a model of designers' thinking process in concept generation called ECF cycle. It consists of three steps, i.e., (1) Externalization: the step for representing design concepts with drawings and language, (2) Classification: the step for classifying concepts with function trees, and (3) Finding voids: the step for finding potentials of new concepts called void, which is a defect of the classification. Then, this research builds a new method of concept generation incorporating the theory of solving inventive problems (TRIZ). The method is based on a quick reference table of TRIZ principles, which helps designers to create a new concept corresponding to a void found by ECF cycle. A case study of concept generation of new running shoes is demonstrated in order to verify the ability of the proposed method.

著者

畠山 貴充 平野 幸助 中村 雄太 藤澤 彰宏 土屋 貴司 山口 達也 千田 有一 吉村 達也

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.851, pp.16-00531-16-00531, 2017 (Released:2017-07-25)

参考文献数

21

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In the present paper, development of an automatic spinach harvester is discussed. Our research group has been developing a prototype harvester and many filed tests have been successfully executed. The field test results show that spinach can be picked up automatically without being grasped after their roots being cut at specified position in soil. The harvester equips two degrees of freedom control units, such as the arm length control unit and the arm angle control unit, for controlling a root-cutting blade which follows the specified path under the ground. In the present paper, modeling and control design for the arm length control is discussed. First, a control design model is developed by several system identification techniques. Next, an I-PD controller is designed by the robust control design procedure. Control performance is verified by numerical simulations and field tests.

著者

朝岡 忠 水内 郁夫

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.851, pp.16-00483-16-00483, 2017 (Released:2017-07-25)

参考文献数

41

---

This paper describes how to exploit the elasticity and the dynamic coupling of a multi-link robot with elastic elements to improve the motion ability without depending on only actuator power. The focus is on swing motion (e.g., throwing or kicking motion) in this paper. The prime purpose of the swing motion is to increase the kinetic energy of an end-link (e.g., hand or foot). This paper proposed a method to generate a swing motion pattern for the increase of the kinetic energy of the end-link. In general, the multi-link robot has high-power actuators in the base side. The high-power actuators can produce a large amount of mechanical energy. Mathematical models were constructed to transfer mechanical energy from the base side toward the end side by exploiting the elasticity and the dynamic coupling. The swing motion pattern was generated on the basis of the models. The results of simulation experiments showed that the kinetic energy of the end-link increased explosively. The reason was that a large amount of energy produced by the actuators in the base side was transferred toward the end side.

著者

西嶋 春幸 定村 和佳 川村 洋介 中川 勝文

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.851, pp.17-00192-17-00192, 2017 (Released:2017-07-25)

参考文献数

13

---

Recently, the refrigeration air conditioner and heat pump system using the two-phase flow ejector is beginning to appear, as the efficiency of the ejector cycle is improved largely in comparison with the conventional system. Shock and expansion waves can occur in the internal flow fields of the ejector, and the effect of the pressure fluctuation by those waves must be considered on the designs of the ejector. In this study, the pressure fluctuation of the shock wave appeared at the outlet of the two-phase flow nozzle are measured in the HFO1234yf refrigeration cycle. It was clarified by experiment that the amplification frequency components of pressure fluctuations are increased with the strength of the shock waves and the attenuation frequency components are increased with increase of liquid void fraction of downstream shock waves.

著者

太田 高裕

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.851, pp.17-00153-17-00153, 2017 (Released:2017-07-25)

参考文献数

17

被引用文献数

3

---

Shot peening is widely applied in the automotive and aerospace industries in order to improve the fatigue strength of the metal components by compressive residual stress. In the case of large components, the peening process is generally performed by moving peening equipment that follows a trajectory on the component surface by means of a robot. In order to construct a robot program for the shot peening of complex components, this study aimed to obtain a functional approximation of the impact pressure distribution in the shot stream. The impact pressure distributions were measured with pressure measurement films (Prescale) and a pressure distribution mapping system. The dependence of the mean impact pressure in the shot stream on the shot mass was in good agreement with the dependence of the arc height of the Almen strip on the shot mass. The impact pressure distributions using various shot masses and standoff distances were measured and approximated by modified Gaussian distribution functions, which included the saturation curve. Three coefficients in the modified Gaussian distribution functions depended on the shot mass and the standoff distance. The modified Gaussian distribution functions were used to determine the impact pressure distributions of a twice-shot peened samples. These calculated values were in good agreement with the experimental results. However, for tilted shot peening, the impact pressure distributions were more complex because the standoff distance at each position on the film was different. The impact pressure distributions of the tilted conditions calculated by the modified Gaussian distribution function, which considered the variation in the standoff distance, were in good agreement with the experimental results for a tilt angle ranging from 30° to 90°.

著者

武末 翔吾 岩前 翔太 亀山 雄高 小茂鳥 潤 深沢 剣吾 三阪 佳孝

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.851, pp.17-00151-17-00151, 2017 (Released:2017-07-25)

参考文献数

19

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To improve the high-temperature oxidation resistance of grade S45C carbon steel, we formed a Cr / Ni diffusion layer on the surface of carbon steel by atmospheric-controlled induction heating fine particle peening (AIH-FPP) treatment. Cr and Ni particles were mechanically milled in planetary ball mills and used as shot particles in the AIH-FPP treatment to create a Cr / Ni diffusion layer. High temperature oxidation tests were carried out at 900°C for 100 hours to evaluate the high-temperature oxidation resistance of the AIH-FPP treated specimen. The mechanically milled particles and specimen were analyzed using a scanning electron microscope, an energy dispersive X-ray spectrometer, and an X-ray diffractometer. Results show that the AIH-FPP treated specimen prepared using mechanically milled particles formed a Cr / Ni diffusion layer on the carbon steel. The carbon steel sample with the Cr / Ni diffusion layer exhibited improved high-temperature oxidation resistance compared to the untreated sample. This is due to the formation of Cr and Ni oxidized layers on the treated surface, which inhibited oxidation of the inner substrate. The results indicate that a Cr / Ni diffusion layer formed by AIH-FPP treatment using mechanically milled particles can improve the high-temperature oxidation resistance of grade S45C carbon steel.

著者

定森 友也 高橋 宏治 古池 仁暢

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.851, pp.17-00096-17-00096, 2017 (Released:2017-07-25)

参考文献数

11

被引用文献数

1

---

In this study, the effect of shot peening on rolling contact fatigue life of bearing steel was investigated under contaminated lubrication. Shot peening was carried out on bearing steel SUJ2 specimens. Peened specimens were polished to remove the dimples generated by shot peening. The distribution of Vickers hardness and residual stress of the specimens were measured before and after the shot peening. The resistance to indentations was compared by examining the profile of the Vickers indentations. Then, rolling contact fatigue tests were carried out under contaminated lubrication. The material hardness was improved up to about 100 HV on the surface to a depth of 300 μm, and compressive residual stress was generated up to 1546 MPa at a depth of 25 μm due to the shot peening. In addition to the width and the depth of the Vickers indentation, the ridge height which causes the stress concentration around the indentation, was reduced by 17% by the shot peening. The rolling contact fatigue life associated with a 50% reliability (L50) was improved 62 % by the shot peening. However, the improvement of rolling contact fatigue life associated with a 90% reliability (L10) was only 26 % because of the increase in dispersion of the fatigue lives due to surface cracks created by the shot peening. Based on the present result, the increase of surface hardness and generating the large compressive residual stress near the surface by shot peening was found to be effective in increasing the rolling contact fatigue life in contaminated lubrication.

著者

野田 尚昭 赤木 大地 沈 雨濃 高木 怜 池田 朋弘 佐野 義一 高瀬 康

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.851, pp.17-00034-17-00034, 2017 (Released:2017-07-25)

参考文献数

25

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High-speed tensile testing is now being recognized as a standard testing method for evaluating the impact strength of engineering materials. The impact speeds of Izod and Charpy tests cannot be controlled and therefore do not correspond to the real failure of real products. The brittle-ductile transition of structural materials is affected by the temperature and loading speed. In the high-speed tensile test, it is necessary to obtain the strain rate at the notch root accurately to understand the effect of impact load. For smooth specimens, the strain rate can be determined from the tensile speed u/t and specimen length l as εsmooth = u/tl. For notched specimens, however, the strain rate at the notch root εnotch should be analyzed accurately. In this study, therefore, the strain rate concentration factor defined as Ktε = εnotch/εsmooth is studied with varying the notch geometry. To predict the strain rate concentration factor Ktε accurately, the relationship between Ktε and the stress concentration factor Kt* = σmax/σgross is investigated. Here, σgross is the remote tensile stress and P is the tensile load. It is found that the strain concentration factor Ktε can be estimeted from stress concentration factor Kt* when the relative notch depth 2t/D≦0.5 (t : notch depth, D : the specimen diameter).

著者

福岡 俊道 野村 昌孝

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.851, pp.17-00018-17-00018, 2017 (Released:2017-07-25)

参考文献数

13

被引用文献数

1

---

Titanium and titanium alloys have a lot of excellent characteristics when used for the parts and components of machines and structures. As for bolted joints, however, they are used only for some limited cases because of the high cost. Their specific characteristics, e.g., low weight and high resistance to corrosion, are highly attractive from the engineering point of view. In this paper, thermal contact coefficients at the interface composed of titanium and titanium alloys are measured, and the empirical equations for evaluating the coefficients are derived in the same form proposed in the previous papers. Then, heating experiments of bolted joints, tightened by titanium bolts, are conducted to examine how the bolt preloads vary when subjected to thermal loads, and the bolt preload variations are compared to the case tightened by carbon steel bolts. In the next place, aiming at a broader use of titanium and titanium alloy bolts, numerical analyses are performed to demonstrate the effectiveness of those bolts by incorporating the foregoing thermal contact coefficients into the finite element formulation. The numerical results are favorably in good agreement with the experimental ones, and they suggest that threaded fasteners made of titanium alloys can be favorably applied to the joints whose clamping forces are likely to decrease when subjected to thermal loads.

著者

世木 選 新井 智貴 福島 槙一郎 細井 厚志 藤田 雄三 武田 一朗 川田 宏之

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.83, no.851, pp.16-00571-16-00571, 2017 (Released:2017-07-25)

参考文献数

15

被引用文献数

1

---

Fatigue properties of the thick carbon fiber reinforced plastic (CFRP) laminates with toughened interlaminar layers in the out-of-plane direction (Z direction) and in the in-plane transverse direction (T direction) were evaluated experimentally. Spool specimens were machined from the thick mother plates which were laminated prepregs of T800S/3900-2B unidirectionally. The specimens were attached to metal tabs to apply loads in the thickness direction of the specimen. The tensile strengths in Z and T direction were measured by static tensile tests and S-N curves were obtained by fatigue tests at a stress ratio of R=0.1. As the results, the tensile strength in Z direction was 24% lower than that in T direction. Fatigue strength in Z direction at 106 cycles was also 25% lower than that in T direction. It was observed using a digital microscope that the fracture occurred in intralaminar layers in both static tensile tests and fatigue tests in Z direction. The thermal residual stress which was generated during the fabrication process and the stress distribution by mechanical loadings in spool specimens were calculated by finite element analysis. The calculated results showed that compressive residual stress applied in intralaminar layers in T direction by restraining the thermal deformation. It is found that the static tensile and fatigue properties in Z direction were almost the same as those in T direction by evaluating with the stresses applied in the nearest intralaminar layer to the minimum cross-section in the spool specimen.