|
Affiliation |
Faculty of Urban Innovation, Division of Urban Innovation |
|
Job Title |
Assistant Professor |
|
Research Fields, Keywords |
Structural engineering, Non Destructive Inspection, Machine learning, Data science, High-strength bolted friction joints |
|
Web Site |
|
|
Related SDGs |
|
HIRAO Kensho
|
|
Education 【 display / non-display 】
-
-2022.9
Tokyo Institute of Technology Doctor Course Completed
-
2017.4-2019.3
Tokyo Institute of Technology Master Course Completed
Degree 【 display / non-display 】
-
Doctor of Engineering - Tokyo Institute of Technology
Campus Career 【 display / non-display 】
-
2022.10
Duty Yokohama National UniversityFaculty of Urban Innovation Division of Urban Innovation Assistant Professor
Academic Society Affiliations 【 display / non-display 】
-
2017
Japan Society of Civil Engineers
Research Areas 【 display / non-display 】
-
Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Structure engineering and earthquake engineering
-
Others / Others / Steel structure
Qualification acquired 【 display / non-display 】
-
First Kind of High School Teacher License
Thesis for a degree 【 display / non-display 】
-
Quantification of Uncertain Influential Parameters Affecting the Structural Performance Evaluation of High Strength Bolted Friction Joints
Kensho HIRAO
2022.9
Doctoral Thesis Single Work [Reviewed]
Papers 【 display / non-display 】
-
Kensho HIRAO, Quang Vy TRAN, Hiroshi TAMURA
Journal of Structural Engineering 70A ( 0 ) 61 - 74 2024.3 [Reviewed]
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers Joint Work
There is concern that the slip coefficient of high-strength bolted joints with different faying surfaces may be lower than that of conventional joints, and it has been reported that the slip coefficient is improved by inserting friction shims. In this study, shims were modified to be disk-shaped, which can be inserted into each bolt hole, for application to arbitrary bolted joints, and their slip resistance was evaluated by slip resistance tests. As a result, it was confirmed that a slip coefficient of 0.6 or higher could be expected with the insertion of shims. Failure modes of the contact surfaces were also investigated by dismantling the specimens after the test and observing the contact surfaces.
-
A study on stabilizing mechanism of flap countermeasures mitigating VIV of a box girder bridge section
Phan Duc Tam, Hiroshi Katsuchi, Wang Jiaqi, Hiroshi Tamura, Kensho Hirao
IOP Conference Series: Materials Science and Engineering 1289 ( 1 ) 1 - 15 2023.8 [Reviewed]
Language：English Publishing type：Research paper (scientific journal) Joint Work
-
ULTRASONIC HIGH-STRENGTH BOLT AXIAL FORCE EVALUATION BY MACHINE LEARNING-BASED TO WAVEFORM ANALYSIS
Kensho HIRAO, Keigo SUZUKI, Kastumi MORITA, Yuichi ITO, Kouichi TAKEYA and Eiichi SASAKI
Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 78 ( 1 ) 108 - 120 2022 [Reviewed]
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers Joint Work
Bolt axial force of high-strength bolted joints decreases due to deterioration. One of the conventional methods to evaluate the bolt axial force is ultrasonic testing. However, quantitative evaluation of the bolt axial force is controversial in terms of accuracy, and some problems remain for practical use. This study attempts the accurate evaluation of the bolt axial force by ultrasonic testing. The time zone analysis of the ultrasonic waves indicated that the waveform in the initial time zone includes bolt axial force information. The parasitic discrete wavelet transform (P-DWT) was applied to improve the evaluation accuracy. As a result of targeting bolts manufactured in the same lot, machine learning using linear regression evaluated the unknown bolt axial force within an error of 6% or less. Therefore, it was shown that the proposed method of this study corresponds to the existing bolt and can evaluate the bolt axial force with high accuracy.
-
Kensho HIRAO, Eiichi SASAKI, Yuichi ITO, Kouichi TAKEYA, Ayako AKUTSU
Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 78 ( 3 ) 508 - 519 2022 [Reviewed]
Authorship：Lead author Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers Joint Work
<p> Recently, inorganic zinc-rich paints have been increasingly applied to the faying surfaces of high-strength bolted friction joints. The coating thickness of the faying surface is said to affect the slip coefficient of the bolted joint. If the coating thickness on faying surfaces of bolts in existing joints can be measured without disassembly the joints, it is possible to evaluate the structural performance of bolted joints on the basis of the current coating thickness on the faying surfaces and the slip coefficient. Furthermore, if it becomes possible to measure areas of high contact pressure, where the coating thickness changes after joining, this information could be useful for discussing the mechanism of structural performance of bolted joints. In this study, the construction of an ultrasonic measurement method with machine learning showed the feasibility of evaluating the coating thickness on the backside of a single steel plate. Subsequently, an attempt was made to evaluate the coating thickness on faying surfaces of bolts in existing joints without disassembly.</p>
-
APPLICABILITY OF PRETENSIONED BOLTED JOINTS INCLUDING DIFFERENT CONTACT FACES
TAMURA Hiroshi, MINAMI Kuniaki, YOSHIOKA Natsuki, UCHIDA Daisuke, MORO Mitsuru, HAMA Tatsuya, HIRAO … Show more authors
TAMURA Hiroshi, MINAMI Kuniaki, YOSHIOKA Natsuki, UCHIDA Daisuke, MORO Mitsuru, HAMA Tatsuya, HIRAO Kensho Hide authors
Journal of Japan Society of Civil Engineers, Ser. A1 (Structural Engineering & Earthquake Engineering (SE/EE)) 76 ( 2 ) 255 - 274 2020
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japan Society of Civil Engineers Joint Work
<p> In frictional type pretensioned bolted joints, one specification is employed for contact faces in each joint in principle. Meanwhile, in some cases such as protection works of existing bridges and fabrication of box girders made of weathering steel without coating, introduction of usage of different contact faces in one joint might often allow labor-saving and accelerated works.</p><p> In present study, bolted joints including different contact faces are defined as a hybrid faying surfaces joint, and 33 bolted joint specimens were used in bolt pretension relaxation test and slip test. This paper reports these results and compares degree of pretension loss and slip resistance in hybrid faying surface joints with homogeneous (i.e. normal) joints. Finally, also on the basis of previous research, the applicability and slip coefficient for designing of hybrid faying surfaces joints are discussed regarding.</p>
Review Papers 【 display / non-display 】
-
BIMによるデジタルツイン技術を用いた鉄道橋のメンテナンスの最適化 -オーストラリアのミナムラ鉄道橋を対象とした実証実験結果の報告-
平尾 賢生，黒田璃紗，駒場 駿介，鹿野 光一，島田 剛気，島野 孝則，末松 慎介，土田 僚，平井 貴大，舟橋 景介，柳 博文
橋梁と基礎 57 ( 12 ) 63 - 65 2023.12 [Reviewed] [Invited]
Authorship：Lead author Language：Japanese Publishing type：Book review, literature introduction, etc. Joint Work
-
Asia Steel Bridge Competition 2024
Keigo SUZUKI, Hiroshi TAMURA, Yuki BANNO, Kouichi TAKEYA, Ayako AKUTSU, Kensho HIRAO
Bridge and Foundation Engineering 58 ( 11 ) 56 - 56 2024.11
Language：Japanese Publishing type：Article, review, commentary, editorial, etc. (other) Joint Work
-
3Dプリンタで製作されたコンクリート歩道橋の持続可能性評価
舟橋 景介，平尾 賢生，今村 光希，大庭 大，桐本 翔平，倉橋 和希，駒場 駿介，島野 孝則，末松 慎介，土田 僚，柳 博文
橋梁と基礎 58 ( 11 ) 53 - 55 2024.11
Language：Japanese Publishing type：Book review, literature introduction, etc. Publisher：株式会社建設図書 Joint Work
-
橋軸周りの回転工法による鋼橋の架替え工事 -チェコ共和国 フラチョルスキー貯水池に架かる橋梁-
黒田 璃紗，平尾 賢生，大庭 大，桐本 翔平，倉橋 和希，駒場 駿介，島野 孝則，末松 慎介，土田 僚，舟橋 景介，柳 博文
橋梁と基礎 58 ( 9 ) 49 - 51 2024.9
Language：Japanese Publishing type：Book review, literature introduction, etc. Publisher：株式会社建設図書 Joint Work
-
ハマースミス橋の修復プロジェクト -イギリス・ロンドン-
島野 孝則，平尾 賢生，桐本 翔平，土田 僚，大庭 大，倉橋 和希，黒田 璃紗，駒場 駿介，島野 孝則，末松 慎介，舟橋 景介，柳 博文
橋梁と基礎 58 ( 8 ) 143 - 143 2024.8
Language：Japanese Publishing type：Book review, literature introduction, etc. Joint Work
Awards 【 display / non-display 】
-
2024.10 土木学会 マーカ型ARを用いた橋梁点検支援システムにおける空間重畳精度向上の試み
Individual or group name of awards：平尾 賢生
-
Best Presentation Award
2024.4 The 70th Symposium on Structural Engineering Evaluation for slip resistance of bolted joints including different contact surfaces with disk-type friction shims inserted
Individual or group name of awards：Kensho HIRAO
Other external funds procured 【 display / non-display 】
-
Loose bolt detection by nut rotation history using AI image processing
2023.7 - 2024.6
Investigator(s)：Kensho HIRAO
Authorship：Principal investigator
-
Evaluation of the existing performance of high-strength bolted friction joints considering the effect of uncertainty
2022.6 - 2023.5
Investigator(s)：Kensho HIRAO
Authorship：Principal investigator
-
Evaluation of the existing performance of high-strength bolted friction joints considering the effect of uncertainty
2021.6 - 2022.5
Investigator(s)：Kensho HIRAO
Authorship：Principal investigator
Presentations 【 display / non-display 】
-
Trial for improving the accuracy of spatial superimposition in bridge inspection support system using marker-type Augmented Reality Display
Kensho HIRAO, Ryudo KASHIMA, Hiroshi TAMURA, Jiaqi WANG, Hiroshi KATSUCHI
2024.9 JSCE
Event date： 2024.9
Language：Japanese Presentation type：Oral presentation (general)
Venue：Miyagi Country：Japan
In bridge proximity visual inspections, work is often required in dark and cramped spaces. In addition, since many members have similar appearances, there is a possibility of misidentifying the name of a member or its current location. Therefore, there is a need to develop an augmented reality (AR)-based bridge inspection support system to reduce the workload of on-site inspectors, however, the accuracy of the system is a problem and the system has not yet been widely used in the field. In this study, a combination of marker-type AR and a unique system was tried to achieve high accuracy. The performance of the system was also evaluated inside a steel box girder of a road bridge. As a result, it was confirmed that the system developed in this study ensures practical accuracy.
-
舗装状態が車両と橋の相互作用に及ぼす影響に着目した鋼I桁の疲労損傷に関する数値的研究
宮崎凌也，シリンゴリンゴディオニシウス，田村洋，平尾賢生，勝地弘，王嘉奇
土木学会第79回年次学術講演会 2024.9 土木学会
Event date： 2024.9
Language：Japanese Presentation type：Oral presentation (general)
Venue：宮城 Country：Japan
-
遮風壁が矩形柱の空力安定性に与える影響
王嘉奇，五十嵐遼馬，勝地弘，ヴィライヴォンアノシット，田村洋，平尾賢生
土木学会第79回年次学術講演会 2024.9 土木学会
Event date： 2024.9
Language：Japanese Presentation type：Oral presentation (general)
Venue：宮城 Country：Japan
-
表面加工による斜張橋ケーブルの空気力低減メカニズムの検討
奥田一喜，勝地弘，王嘉奇，田村洋，平尾賢生
土木学会第79回年次学術講演会 2024.9 土木学会
Event date： 2024.9
Language：Japanese Presentation type：Oral presentation (general)
Venue：宮城 Country：Japan
-
高力ボルト摩擦接合継手異種接合面のすべり係数に関する載荷速度依存性評価
本多隆盛，田村洋，平尾賢生，勝地弘，王嘉奇
土木学会第79回年次学術講演会 2024.9 土木学会
Event date： 2024.9
Language：Japanese Presentation type：Oral presentation (general)
Venue：宮城 Country：Japan
Charge of on-campus class subject 【 display / non-display 】
-
2024 Topics in Machine Learning
Graduate School of Urban Innovation
-
2024 Experiment in Civil Engineering B
College of Urban Sciences
-
2024 Exercises on Structural Mechanics
College of Urban Sciences
Charge of off-campus class subject 【 display / non-display 】
-
物理1及演習
2024.4 Institution：法政大学
Level：Undergraduate (specialized)
Committee Memberships 【 display / non-display 】
-
Japan Steel Bridge Engineering Association "Working Group on Joints of Steel Bridges"
2022.11 Academic Member
Committee type：Academic society
-
Techno-Science Research Journal
2024.11 Editor
Committee type：Academic society
-
Bridge and Foundation Engineering
2022.10
Committee type：Other