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

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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

田中 嘉津彦 藤田 祐介

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.850, pp.16-00540-16-00540, 2017 (Released:2017-06-25)

参考文献数

16

被引用文献数

2

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The friction characteristics on sliding part between piston and cylinder in a swash plate type piston pump in which improvement of the power density is demanded affect the equipment performance and the efficiency. In this paper, targeting a straightly cylindrical piston and tapered pistons, the effects of geometric shape of the piston on the friction characteristics have been investigated based on both the results of friction force measurement using a model machine and the numerical calculation considering mixed lubrication. Moreover, the effectiveness of adopting each of the pistons to the swash plate type piston pump has been examined from view point of friction characteristics. The results are summarized as follows: (1) Optimum taper angle of the piston which can improve the friction characteristics will exist under severe lubrication conditions. (2) The degree of friction characteristics improvement can be formulated as a function of the Sommerfeld number which is one of important parameters to determine the bearing performance. (3) Adoption of tapered pistons may improve the friction characteristics under mild lubrication conditions. (4) The tapered piston will whirl widely in the cylinder than in the case of the straightly cylindrical piston, load carrying capacity due to squeeze effect of the fluid can be expected to increase.

著者

小野 京右

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.850, pp.17-00091-17-00091, 2017 (Released:2017-06-25)

参考文献数

26

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Vibration characteristics of a flying head slider in hard disk drives at touchdown attract strong interest because head‒disk spacing must be decreased to less than 1 nm in order to increase recording density. This study first evaluates head‒disk interfacial force based on rough surface adhesion contact models and a simple air-bearing force model. Then, microwavinessexcited vibration of single-degree-of-freedom slider model at touchdown was numerically simulated in more detail than the previous study. It was found that the slider exhibits a MW-excited vibration having low frequency components of less than 100 kHz at touchdown and shifts to severe contact state near the boundary of static instability onset. When a small static unstable region is generated by decreasing air-bearing stiffness ratio, the occurrence of the low frequency spacing variation is interrupted by temporal flying state (loss of contact). When the static unstable region further increases by decreasing air-bearing stiffness ratio, the spacing variation with low frequencies can appear only at the beginning of contact and immediately jumps to a light contact state and then shifts to a perfect flying state during a long input power range and eventually jumps to a heavy contact state. These calculated results seem to correspond to the actual slider dynamic behaviors at touchdown in the inner, outer and middle diameter regions. The possibility of surfing recording is discussed from the analytical and experimental evidences.

著者

吉田 秀久 小嶺 長芳 山口 秀谷

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.15-00116, (Released:2015-05-22)

参考文献数

19

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For the design of steering assistance system when running at high speed and modeling of a driver model necessary to effect evaluation and inspection, goal of this research is to make the driver model which models the driver's steering torque over a series of steering behavior. First step of this research, modeling of a driver steering in high-speed running is targeted for the steering torque behavior during the lane change that a driver steers actively and lane keeping that a driver keeps the lane under the crosswind disturbance passively. So the modeling for the steering torque behavior is proposed considering the lateral deviation in the front view point and the reaction torque from the steering wheel. It is proposed that the steering torque state transition changes from a course change action to a lane keeping action. It is confirmed that reproducibility of lane keeping action to an experimental result improves. Significant test did the driver parameter and its feature is made clear.

著者

高橋 翼 中村 寛子 木村 啓志

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.850, pp.16-00560-16-00560, 2017 (Released:2017-06-25)

参考文献数

16

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Nowadays, in vitro fertilization (IVF) of mammalian embryos is an essential technique in the reproductive technology and other related life science fields. However, the fertility rate by this technique is still less than 25%. Therefore, a novel in vitro fertilization method which obtains high fertility rate has been highly desired to the reproductive technology. In this study, we proposed and developed an in vitro embryo production device which allows three steps of sperm selection, fertilization and culture on a microdevice. To realize this concept, we integrated the sperm sorting function combining with swim-up and swim-down methods onto the device. To evaluate the device functions, sperm sorting experiment, in vitro fertilization experiment, and embryo culture experiment have been carried out. As results, we concluded that the device has ability to produce high quality embryos by integrating the sperm sorting function. This concept will open and enhance the management of in vitro fertilized embryos for assisted reproductive technology, livestock breeding, and fundamental stage research by further development.

著者

重松 康祐 坪内 孝司 皿田 滋

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.850, pp.17-00040-17-00040, 2017 (Released:2017-06-25)

参考文献数

14

被引用文献数

1

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This paper describes tip-over prevention control of a teleoperated excavator based on center of gravity (CoG) and zero moment point (ZMP) prediction. This method predicts a future CoG and ZMP when an operation input is given. This allows the determination of the risk of tip-over by the operation input before an excavator moves. When the risk is detected, the operation input to the actuator is modified or stopped automatically to prevent from tip-over. Future CoG and ZMP is predicted by computing the movement of a teleoperated excavator based on an approximate excavator movement model. The proposed method successfully demonstrates tip-over prevention via scaled model experiments of the hydraulic drive.

著者

山田 泰之 吉浜 舜 岩崎 祥大 芦垣 恭太 松本 幸太郎 羽生 宏人 中村 太郎

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.850, pp.16-00576-16-00576, 2017 (Released:2017-06-25)

参考文献数

13

被引用文献数

1

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In recent years, the demand for rocket launching has increased due to the development of space technology. However, using inexpensive rockets is not always possible. Although the cost of solid-propellant rockets is relatively reasonable, safely manufacturing a large amount of solid propellant is difficult, and the manufacturing process is disjointed. Therefore, safe and continues manufacturing of solid propellant is necessary. On the basis of the movements of the intestinal tract, we proposed that the movements required for transport and mixing of solid propellants are possible to achieve without the application of a large shear force. The peristaltic motion enables not only the mixing but also conveying even high viscosity slurry. By mimicking these intestinal movements, we have considered and developed the peristaltic pumping by driven artificial muscle as one of the candidates for the continuous and safety mixer. In this research, the mixing completeness of the composite solid propellant slurry by the peristaltic pumping mixer was estimated. The result showed that the mixer we proposed could mix the propellant slurry. In the propellant samples, these variances were sufficiently small. An appropriate combustion state as a solid propellant was confirmed.

著者

坂本 秀一 石田 宗弘 珍田 美月

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.850, pp.16-00575-16-00575, 2017 (Released:2017-06-25)

参考文献数

14

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In this article, we examined several longitudinal-sectional sizes of a silencer whose volume was limited by the thickness and aperture ratio of the ventilation door. We report the results of improvement in the sound attenuation properties of these shapes. As an evaluation method for the silencer, we measured transmission losses using an impedance measurement tube and calculated them on the basis of a theoretical analysis. The following results were obtained from the evaluation of the silencer using the measurement and calculation results and from the verification of the improved shape of a silencer and silencer array. For a side branch tube silencer with a 1/3 aperture ratio, assuming that it is installed into the ventilation door, we observed a side branch tube with an linear expanded longitudinal-sectional shape by improving the shape using the theoretical analysis of transmission losses. In addition, as a result of the experiment with a sample on the basis of the theoretical analysis, both the experimental and the theoretical analysis were in good agreement. Furthermore, the expanded shape of the longitudinal-section of the side branch tube decreased the frequency of the sound attenuation peak. It was found that a silencer with a combination of four of these silencers can be arrayed side-by-side in a ventilation door; this results in a flat transmission loss of more than 5 dB over a broad band.

著者

大久保 光 福田 宙央 坪井 涼 田所 千治 佐々木 信也

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

pp.15-00679, (Released:2016-06-10)

参考文献数

13

被引用文献数

1

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Tribological properties of a diamond-like carbon film were investigated under lubrication with commercial fully formulated oils. Friction tests were carried out for a hydrogenated amorphous carbon (a-C:H)/steel tribopair under lubrication with the four types of fully formulated oil using a reciprocating type ball-on-disk tribo-tester. To clarify the friction and wear mechanisms, surface analysis, such as Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and atomic force microscopy (AFM), were conducted on the wear tracks of a-C:H disks. The results of friction tests and surface analysis show that the properties of tribofilms on DLC films play important roles in determining the tribological properties of DLC films under lubrication with fully formulated oils.

著者

今西 大輔 西名 慶晃 栗原 康行

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.850, pp.16-00554-16-00554, 2017 (Released:2017-06-25)

参考文献数

8

被引用文献数

1

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In recent study, active thermography has reached a high status as an easy and speedy defects inspection method in a NDT field. This paper newly proposes a remote and non-contact NDT method using a sonic-IR for detecting and evaluating of fatigue cracks at runway girder of the overhead crane in the steel making plant. In this method, fatigue cracks are detected as localized high temperature areas caused by friction and collision at crack surfaces with an infrared camera, applying a high-amplitude ultrasonic vibration. In this paper, sonic-IR method is applied to remote and high-efficient crack inspection of the runway girder in the overhead traveling crane. Target crack located in high place can be detected using this method without setting up scaffolding for inspection. And the threshold of vibration amplitude to generate the sufficient heat for crack detection is clarified. Therefore the system to prevent missing the crack by unsuccessful vibration transmission from vibrator is developed applying monitoring the vibration.Time and cost saving inspection method in runway girder of the overhead traveling crane is carried out using this NDT technique.

著者

金子 康智 今井 貴彦 森 一石 大山 宏治

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.850, pp.16-00536-16-00536, 2017 (Released:2017-06-25)

参考文献数

9

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A vane used in a low pressure end of steam turbine is usually fixed to an inner shroud and an outer ring by welding both ends. In such a vane structure, the damping in loading operation is comprised of the material damping and the aerodynamic damping, because the structural damping is very small. In addition, steam turbine vanes are sometimes manufactured in a half-ring structure, where all vanes in a upper half and a lower half are connected by the shroud. In such a half-ring structure, the vane exhibits closely spaced natural frequencies of Toop (Tangential out-of-phase) modes, in which each vane in a half-ring vibrates like a fixed-fixed beam in a different phase. In such a steam turbine vane, the forced vibration and the self-excited vibration of Toop modes may become a serious issue. Therefore, in the design of the steam turbine vane, it becomes indispensable to evaluate the resonant response and the stability of Toop modes under the high loading condition. In this study, first, the vibration characteristics of steam turbine vane with a half-ring structure are studied by use of the results of FE analysis. Second, the reduced order model (the equivalent spring-mass model) of a half-ring structure is assembled, based on the results of FE analysis. Finally, the forced response analysis of the mistuned system of a half-ring structure is carried out, using the reduced order model and the Monte Carlo simulation. From these results, the vibration response characteristics of steam turbine vane with a half-ring structure are clarified.

著者

兼森 祐治 半田 康雄

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

vol.83, no.850, pp.16-00513-16-00513, 2017 (Released:2017-06-25)

参考文献数

18

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Axial thrust forces acting on an impeller of a diffuser type mixed flow pump and the behavior of the axial thrust generated by the vortex occurrence in a pump intake sump were studied. The thrust from distinct discontinuities, such as the hysteresis phenomenon, was measured from a pump's hydraulic performance. In pump partial load operation the axial thrust increases discontinuously because of the reverse flow at impeller inlet. Synchronous and non-synchronous components of axial thrust increase during the onset of reverse flow zones. A prediction method for static axial thrust was derived based on Oshima's theory, accounting for the pressure reduction at pump suction bell-mouth caused by a vortex. Qualitative comparison of the predicted results with the actual static axial thrust results measured during the experiment, showed reasonable similarities around pump best efficiency flow rate. The thrust was measured using a pump intake sump test apparatus in which both an air-entrained surface vortex and a submerged vortex could occur. The level of dynamic axial thrust is dependent on the pump intake sump water level and the dynamic axial thrust begins to increase when a full air core vortex occurs at the pump intake. When submerged as well as full air core continuous vortices occur, the axial thrust and the fluctuation of total pump head become abruptly large. The fluctuation of axial thrust becomes the highest when the impeller draws in a large air-drawing vortex, imposing a pressure fluctuation which generates not only a rotational speed but also nZ vane passing and low frequency components.

著者

鶴田 智 川添 博光 森田 真司

出版者

一般社団法人 日本機械学会

雑誌

中国四国支部総会・講演会 講演論文集 2002.40 (ISSN:24242764)

巻号頁・発行日

pp.249-250, 2002-02-21 (Released:2017-06-19)

著者

山崎 哲也 高島 俊

出版者

一般社団法人 日本機械学会

雑誌

ロボティクス・メカトロニクス講演会講演概要集 2008 (ISSN:24243124)

巻号頁・発行日

pp._2P1-I20_1-_2P1-I20_4, 2008-06-06 (Released:2017-06-19)

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Magic is a performance unique to humans that makes use of hand's skills to its maximum extent. It needs enormous efforts to acquire the skills of magic for a skillful man. In this study, a robot hand that can handle a small object in the palm and perform coin magic making full use of its palm and fingers. It is said that the coin magic is one of the most difficult kinds of magic. Therefore, we expect that a robot that can do coin magic may be able to do any magic successfully. In this paper, a mechanism of the robot hand is studied and the control methods of handling coins for the magic is discussed. The robot is assumed to use a Japanese 500 yen coin during the performance and it is assumed that the robot controls the hand by using only the information from the palm sensors. It is the problem how to design the skilful hand, how to construct a control algorithm, and what sensors should be used to sense the state variables of the coin.

著者

藤澤 彰宏 千田 有一

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.850, pp.16-00472-16-00472, 2017 (Released:2017-06-25)

参考文献数

19

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This paper describes about path planning for a root-cutting blade of an automatic spinach harvester. Automatic harvesters for spinach have not been widely used among farmers because mechanical harvesting easily spells bruises to stems and leaves. We have been developing the harvester which successfully harvests spinach without bruising stems and leaves. The path which blade moves in soil is very important in order to attain desired performance and to reduce the amount of soil which is pushed by the blade is the most meaningful factor for successful execution. In this paper, first, we discuss about a method to reduce the amount of soil and proposed a constraint equation for the method. Next, an appropriate path of the blade of the harvester is proposed by using the equation. The effectiveness of the proposed path is verified by numerical simulations based on the Discrete Element Method (DEM).

著者

渡壁 智祥 山本 智彦 深沢 剛司 岡村 茂樹 杣木 孝裕 諸菱 亮太 櫻井 祐 加藤 亨二

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.850, pp.16-00444-16-00444, 2017 (Released:2017-06-25)

参考文献数

9

被引用文献数

1

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A seismic isolation system composed of a thick rubber bearing and an oil damper has been developed for Sodium-Cooled Fast Reactor. One of the advantages of the isolation system is the use of thick rubber bearings to ensure the longer vertical natural period of a plant, thereby mitigating seismic loads to mechanical components. Characteristics of thick rubber bearings have been confirmed through a series of tests. This paper focused on the aging properties of thick rubber bearings, such as basic mechanical properties and ultimate strength. An aging test of thick rubber bearings was conducted using 1/2-scale (800 mm diameter) and 1/8-scale (200 mm diameter) rubber bearings. Aging of the rubber bearings was reproduced using thermal degradation based on Arrhenius law, in which the target of aging periods was 60 years, plant life time. The hysteresis loops of the thick rubber bearings after aging were obtained through horizontal and vertical static loading tests, and the effects of aging were evaluated by comparison with the initial mechanical properties. In addition, for the purpose of further research, the effect of scale by aging was clarified to compare the mechanical properties between the 1/2-scale and 1/8-scale rubber bearings.

著者

田村 伊知郎 松浦 真一

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.850, pp.16-00438-16-00438, 2017 (Released:2017-06-25)

参考文献数

11

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For seismic design of components, elastic response spectrum analysis, which is based on linear response using elastic response spectrum, is generally used as a dynamic analysis of multi-degree-of-freedom(MDOF) systems not only elastic response but also elastoplastic response. Elastoplastic response is different from elastic response due to nonlinearity of the system by yielding of components. Several researchers have proposed response spectrum analysis methods of nonlinear MDOF systems using equivalent linearized methods, which replace a nonlinear system to the linear system equivalent to the nonlinear system on the response. We developed a response spectrum analysis method using elastoplastic response spectrum and not replacing a nonlinear system to the linear system as a dynamic analysis method of nonlinear MDOF systems. This method is obtained from exact equations of motions by just two assumptions; no interaction between natural moods and modal combination rules. We verified this method was effective in the calculated 2-DOF systems. This method is also considered of value for interpretation on the response of nonlinear MDOF systems by spectrum modal approaches.

著者

大谷 充人 花島 直彦 吉田 英樹

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 (ISSN:21879761)

巻号頁・発行日

vol.83, no.850, pp.16-00317-16-00317, 2017 (Released:2017-06-25)

参考文献数

24

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In this study, we discuss a problem to collect observation data with one mobile robot in extensive investigation field. When the measurement of observation data is carried out by the mobile robot, the setting of running-path and navigation are important for appropriate measurement. Usually reciprocating straight paths at even interval are employed to collect data with spatially uniform density. However it is possible that some area between the straight paths requires detailed measurement. The method proposed in this paper makes it possible that in ordinary situation the robot follows the straight path, in the proximity of the area with need of observation it leaves the straight path toward the area, after that returns to the preceding straight path. Recently the path-generating regulator (PGR) has been applied to a tracking problem along a straight passage for car-like robots. The PGR is a control method for a vehicle so as to orient its heading toward a tangent to one of the curves belonging to a family of path functions. In this paper, we append a property to the PGR tracking the straight passage to modify the target heading angle in accordance with necessity of observation and to realize the motion toward the area with need of observation. To confirm the efficiency of the proposed method, two types of simulations are performed. The first simulation shows how a level of necessity of observation and a range to the area changes the locus of the mobile robot. In the second simulation, the mobile robot is satisfactorily guided by the level of necessity of observation obtained from actual measured data in a survey site.

著者

大友 光彰 鈴置 哲典 山本 征治 宮川 浩

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.850, pp.17-00044-17-00044, 2017 (Released:2017-06-25)

参考文献数

5

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This paper studies the condition of reducing knock intensity which is the pressure oscillation initiated by auto-ignition of the end gas. The knock intensity is thought to be decreased by suppressing the reaction rate of auto-ignition. In this study, the effect of the mixture dilution which decreases the reaction rate on the knock intensity was investigated by using a spark ignition engine. In the case of low dilution, knock was observed when the auto-ignition of the end gas occurred. When the dilution ratio was over 30%, there was the condition that the knock did not occur even if the end gas auto-ignited. The combustion with low knock intensity was observed in either case that dilution gas was inert gas or air. The knock intensity was shown as a function of the maximum temperature and the maximum pressure which affected the reaction rate although the knock intensity was affected by the composition of the mixture, load, ignition timing, auto-ignition timing of the end gas and heat release quantity of the auto-ignited mixture.

著者

林 知生 近藤 義広 豊田 浩之 佐藤 重匡 椿 繁裕

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.850, pp.16-00580-16-00580, 2017 (Released:2017-06-25)

参考文献数

10

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We have developed the evaluation method for two performance factors to design the thermal connector: Insertion force of thermal grease and thermal conductance. The thermal connector was comprised of a thermal plug and a thermal socket, and the thermal grease which was filled into the gap between the thermal plug and the thermal socket connected the thermal plug and the thermal socket thermally. Firstly, the insertion force was theoretically calculated using the Bingham plastic model for rheology characteristics of the thermal grease and the slip model on the surfaces of the thermal plug and the thermal socket. The calculated results were in good agreement with the experimental results. Secondly, the experimental results of the thermal conductance between the thermal plug and the thermal sockets at the first connection to the 20 times connection were -1 to +26 percent greater than the theoretical value. The reason why some experimental results exceed the theoretical results is the eccentricity between the thermal plug and the thermal socket. In addition, the filling status of the thermal grease in the gap was visualized by ultrasonic testing. The results after the 20 times connections showed there were some voids in the thermal grease and the area of voids was 4 percent of the heat transfer area. Therefore, the thermal conductance was mostly not influenced by the voids. Finally, it was found that the proposed methods to predict the insertion force and thermal conductance were reasonable.