Noritsugu Umehara

Noritsugu Umehara

orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2021 in Tribology International
Verified
Journal Article
Closed access
KKK.A.M. Kassim
K.A.M. Kassim
TTT. Tokoroyama
T. Tokoroyama
MMM. Murashima
M. Murashima
WLW.-Y. Lee
W.-Y. Lee
NUNoritsugu Umehara
Noritsugu Umehara
MMM.M.B. Mustafa
M.M.B. Mustafa

1 October 2016 in Diamond and Related Materials
Verified
Journal Article
Closed access
YJYoung-Jun Jang
Young-Jun Jang
YKYong-Jin Kang
Yong-Jin Kang
KKKazutaka Kitazume
Kazutaka Kitazume
NUNoritsugu Umehara
Noritsugu Umehara
JKJongkuk Kim
Jongkuk Kim

1 April 2021 in Tribology International
Verified
Journal Article
Closed access
MMMotoyuki Murashima
Motoyuki Murashima
YIYusuke Imaizumi
Yusuke Imaizumi
RMRyo Murase
Ryo Murase
NUNoritsugu Umehara
Noritsugu Umehara
TTTakayuki Tokoroyama
Takayuki Tokoroyama
MTMasayuki Takeshima
Masayuki Takeshima

1 September 2000 in Tribology International
Verified
Journal Article
Closed access
LZLin Zhou
Lin Zhou
KKKoji Kato
Koji Kato
NUNoritsugu Umehara
Noritsugu Umehara
YMYoshihiko Miyake
Yoshihiko Miyake

1 January 2019 in International Journal of Mechanics and Materials in Design
Verified
Journal Article
Closed access
PDF file
MMMotoyuki Murashima
Motoyuki Murashima
SYShouta Yoshino
Shouta Yoshino
MKMasato Kawaguchi
Masato Kawaguchi
NUNoritsugu Umehara
Noritsugu Umehara

11 March 2021 in Journal of Tribology
Verified
Journal Article
Closed access
PDF file
MMMotoyuki Murashima
Motoyuki Murashima
YIYusuke Imaizumi
Yusuke Imaizumi
MKMasato Kawaguchi
Masato Kawaguchi
NUNoritsugu Umehara
Noritsugu Umehara
TTTakayuki Tokoroyama
Takayuki Tokoroyama
INIsami Nitta
Isami Nitta
As the need for higher efficiency of engineering components increases, so does the demand for functional surfaces. While various tribosurfaces (e.g., texturing and coatings) have been developed, many researches are aimed at static functionality. On the other hand, due to a wide range of environmental adaptability and active control, active-morphing surfaces can be highly efficient and robust. In this paper, we demonstrate a novel morphing surface and its realization using additive manufacturing (AM). By using a diaphragm structure, morphing performance is achieved even if a hard resin material is used. When air pressure is applied to the backside of the diaphragm, it changes to a convex shape and vice versa. The concept requires a complex structure for arranging airflow and a solid morphing system. The AM is one great technique to create such complex structures. As a result of actual manufacturing, the created morphing structure realizes a large morphing of 600 μm or more. In addition, the shape changes reversibly depending on the air pressure. The surface also exhibits very interesting tribological characteristics. The surface shows a friction coefficient of about 0.3 with a concavity, and then increases to 0.5–1.7 with a convexity. A real-contact area measurement reveals that the novel property occurs due to change in the real-contact area depending on surface morphology. In conclusion, the present paper provides a new concept of a novel morphing tribosurface, which selectively performs as a low-friction or break-like surface, created using AM.