著者

上西 甲朗 松久 寛 宇津野 秀夫 朴 正圭

出版者

一般社団法人日本機械学会

雑誌

日本機械学會論文集. C編 (ISSN:03875024)

巻号頁・発行日

vol.70, no.697, pp.2624-2630, 2004-09-25

被引用文献数

3

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During a car frontal collision, some part of the occupant's kinetic energy is transferred to the vehicle through the restraint system. The high ratio of the transferred energy has the advantage of protecting the occupant. This phenomenon is called "ride down effect". It is known from experience that if the deceleration of the automotive body is large in the early stages of a collision, the effect becomes large, provided that the vehicle kinetic energy and the maximum value of the automotive body deformation are same. In order to design an automotive body structure taking into consideration the ride down effect, the dynamic relation between the occupant deceleration, which is one of important injury criteria, and the automotive body structure must be studied. However, there have been few researches to analyze the theoretical mechanism of the ridedown effect in detail. In this paper, we formulated ridedown effect focusing on the protection devices using a two-degree-of-freedom model for a vehicle and an occupant. The relationship between the index of the ride down effect and the occupant deceleration caused by crashing the automotive body structure was theoretically analyzed, and an optimum automotive crash design was examined.

著者

佐藤 博則 山下 進介 宇津野 秀夫 松久 寛 山田 啓介 澤田 勝利

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C編 (ISSN:18848354)

巻号頁・発行日

vol.77, no.775, pp.989-1003, 2011 (Released:2011-03-25)

参考文献数

7

被引用文献数

2 2

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Life style related diseases such as hypertension and diabetes promote arteriosclerosis which causes circulatory diseases. It is important to evaluate arterial condition for prevention of circulatory diseases. The pulse wave velocity method has become familiar as a vascular test because it is easy and non-invasively. However, the accuracy of the method seems not to be high because it just compares two points ignoring the frequency dependence and reflection waves from peripheral vessels. In this study theory of pulse wave propagation considering such effects was formulated. A new method to identify the reflection ratio from peripheral vessels and pulse wave velocity was proposed. This method was verified by experiment using a silicon tube and applied to measure the pulse wave propagation of human arm as a case study. The results showed that this method has possibility to apply to measure the pulse wave propagation of human pulse wave.

著者

宇津野 秀夫

出版者

一般社団法人 日本音響学会

雑誌

日本音響学会誌 (ISSN:03694232)

巻号頁・発行日

vol.66, no.10, pp.513-520, 2010-10-01 (Released:2017-06-02)

参考文献数

8

被引用文献数

1

著者

秦 秀敏 宇津野 秀夫 松久 寛

出版者

一般社団法人 日本機械学会

雑誌

ジョイント・シンポジウム講演論文集:スポーツ工学シンポジウム:シンポジウム:ヒューマン・ダイナミックス

巻号頁・発行日

vol.2004, pp.89-94, 2004

被引用文献数

1

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Impact problem between a bat and a ball was studied using vibration modal analysis. Initial kinetic energy of the ball and the bat before the collision is transmitted to their vibration energies and their rigid body kinetic energies. The rebound speed of the ball is theoretically calculated and was measured in the experiments for slow speed impact condition. There was a good agreement between the calculation and experiment. The rebound speed of the ball was also calculated for the high speed impact condition. When the bat hits the ball with relatively high speed, higher order vibration modes appear. Therefore it is possible to increase the rebound speed of the ball by changing the design of the bat, such that the higher order modes are suppressed.