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Affiliation |
Graduate School of Engineering Science Department of Systems Design Engineering Civil and Environmental Engineering Course |
GOTOU Humihiko
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Graduate School 【 display / non-display 】
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-1994.03
Tohoku University Graduate School, Division of Engineering Doctor's Course Completed
Campus Career 【 display / non-display 】
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2016.04-Now
Akita University Graduate School of Engineering Science Department of Systems Design Engineering Civil and Environmental Engineering Course Professor
Research Areas 【 display / non-display 】
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Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Structure engineering and earthquake engineering
Qualification acquired 【 display / non-display 】
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High School Teacher Specialization License (first and second kind,specialization)
Thesis for a degree 【 display / non-display 】
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A numerical technique for finite displacement problems of spacial frames
後藤文彦
1994.03
Single author
Research Achievements 【 display / non-display 】
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ESTIMATION OF VIBRATION CHARACTERISTICS OF MEOTO BRIDGE USING TABLETS WITH ACCELEROMETER
OIKAWA Daisuke, IWASAKI Keito, GOTOU Humihiko, AOKI Yukari
Japanese Journal of JSCE ( Japan Society of Civil Engineers ) 79 ( 7 ) n/a 2023 [Refereed]
Research paper (journal)
<p> It is important to understand vibration characteristics of bridges for estimation of the stiffness of the entire bridge. Generally equipments for vibration measurement are so expensive that everyone can not easily carry out the measurement using the equipments. In this study, we try vibration measurement with enough accuracy using tablet devices with accelerometer for a timber pedestrian bridge. For the most dominant vertically-antisymmetrical mode, error of measured value by the tablet devices to the numerically calculated value is about −4.0%. It shows the utility of vibration measurement using tablet devices with accelerometer. Besides, we discuss vibration characteristics for the measured timber pedestrian bridge, comparing values of natural frequency and of damping constant with the values obtained by the approximate equation for steel/concrete bridges.</p>
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STRUCTURAL PERFORMANCE AND SOUNDNESS EVALUATION OF AGING TIMBER ARCH HIGHWAY BRIDGE
Daisuke OIKAWA , The Late Genjiro SUGANUMA, Hideyuki HONDA and Humihiko GOTOU
Paper Reports on Wood Engineering ( Japan Society of Civil Engineers ) 19 72 - 79 2021.02 [Refereed]
Research paper (journal) Domestic Co-author
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DEGRADATION EVALUATION FOR MEMBERS OF A TIMBER BRIDGE, WHICH HAS BEEN IN SERVICE FOR 27 YEARS
OIKAWA Daisuke, FUJIWARA Arisa, GOTOU Humihiko, NODA Ryu, ISHIKURO Shun
Journal of Japan Society of Civil Engineers, Ser. E2 (Materials and Concrete Structures) ( Japan Society of Civil Engineers ) 77 ( 5 ) I_45 - I_54 2021 [Refereed]
Research paper (journal)
<p> In the history of glued timber bridges in Japan 34 years passed since the first bridge was built in 1987, which is much shorter than that of Europe and the United States. Data about stiffness and strength for glue-laminated timber bridges, which have been in service for more than 20 years and then replaced, have not been enough accumulated. In this study, we measure stiffness and strength for the members of Meoto Bridge replaced in 2020 by static/dynamic methods. As a result, the stiffness of the main structural members, such as arch ribs and stiffeners, was generally reduced by about 10%, while design stresses for the arch members and the floor girders are within the allowable stresses. Thus it is suggested that timber members, which have been in service for more than 20 years, have enough stiffness and strength.</p>
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NUMERICAL MODELIZATION OF TIMBER CONSTRUCTION MATERIALS CONSIDERING EFFECT OF KNOTS
KIMIJIMA Mami, AOKI Yukari, GOTOU Humihiko, VALIPOUR Hamid
Journal of Japan Society of Civil Engineers, Ser. E2 (Materials and Concrete Structures) ( Japan Society of Civil Engineers ) 77 ( 5 ) I_1 - I_7 2021 [Refereed]
Research paper (journal)
<p> Recently, "reduction of CO2 emission" has been raised as a most important topic needed to be solved immediately all over the world and each country has declared its reduction target. It is known that construction industry shared the highly CO2 emissions. Thus the new sustainable materials and/or construction methods must be developed as soon as possible. In this research, it is a final target to develop a new timbersteel hybrid beam as a new sustainable material. It is expected to use timbers for the construction site to reduce CO2 emissions than the ordinal materials such as concrete and steel, so that timbers are now one of the most recognized as a sustainable material. In order to replace the concrete to timbers, the timber beam should have the same or even stronger strength than concrete. Thus, in this research timber and steel are combined to improve the beam engineering characteristics.</p><p> In this paper, as a first step to develop such a sustainable beam, knots are presented in the timber beam, because it is found that knots on the beam showed significant reduction of the strength of the beam according to experimental researches. It is shown that knots on the beam have unique material properties and linearly analyzed using FEM. The results of beams are presented in this paper.</p>
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COLLAPSE BEHAVIOR OF CLT DECK WITH STEEL RAILING POST
OGAWA Kouki, GOTOU Humihiko, SASAKI Takanobu, ARAKI Shogo, AOKI Yukari
Journal of Japan Society of Civil Engineers, Ser. E2 (Materials and Concrete Structures) ( Japan Society of Civil Engineers ) 77 ( 5 ) I_55 - I_63 2021 [Refereed]
Research paper (journal)
<p> While CLT(Cross-Laminated-Timber), which is lightweight and is resistant to fatigue, is expected to apply to bridge deck, it is needed to joint commercially available railing on it. It is important to confirm the safety and to investigate the load bearing performance of the joint part between the railing post and the CLT deck. We show relatively simple modeling of the joint part using general-purpose 3D FEM tool and illustrate the numerical results. The modeling considering elasto-plasticity for both steel and CLT members seems to well simulate the sink deformation behavior of CLT.</p>
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Construction Examples of On-Site Timber Stress-Laminated Box-Beam Bridges
Tomohumi Huzita, Humihiko Gotou, Takanobu Sasaki, Ryu Noda
World Conference on Timber Engineering 2018.08
Research paper (international conference proceedings) Domestic Co-author
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Spacial Beam Analysis using Rotation Group and Rotational Angles about Three Axes
Humihiko Gotou, Takashi Kuwataka, Tetsuo Iwakuma
Advances in Computational Engineering & Sciences 1 837 - 842 2000.08
Research paper (international conference proceedings) Domestic Co-author
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Effect of repeated freeze-thaw cycles on the bending strength of wood
NODA Ryu, ISHIBASHI Kenya, GOTOU Humihiko
MOKUZAI HOZON (Wood Protection) ( JAPAN WOOD PRESERVING ASSOCIATION ) 46 ( 5 ) 251 - 258 2020 [Refereed]
Research paper (research society, symposium materials, etc.) Domestic Co-author
In civil engineering structures constructed in cold snowy regions such as Hokkaido or Tohoku, repeated freezing and thawing of the wooden materials may occur in winter. To understand how the strength of wood changes because of these freeze-thaw cycles, we evaluated the bending strength of both untreated and preservative-treated Sugi (<i>Cryptomeria japonica</i> D. Don) timber under five regimes of freeze-thaw cycles, while varying moisture content.<br>
Each cycle lasted 24 hours, and freeze-thaw regimes were composed of 0, 15, 45, 75, and 90 consecutive cycles. After each sample was subjected to a freeze-thaw regime, a bending test was carried out. There was almost no difference among the values of modulus of rupture or modulus of elasticity in samples subjected to different regimes. Moreover, as modulus of rupture and modulus of elasticity may increase after repeated freeze-thaw cycles, we concluded that the effect of the freeze-thaw cycles on the bending strength of Sugi timber is small. -
Elastic Modulus Correction Formula Obtained Using a Stress Wave Propagation Method
Noda Ryu, Suenaga Yuki, Gotou Humihiko
Mokuzai Gakkaishi ( The Japan Wood Research Society ) 67 ( 2 ) 93 - 99 2021.04 [Refereed]
<p>To evaluate the strength of structural members using a stress wave propagation method, it is necessary to determine a constant elastic modulus value, regardless of the sensor insertion position and distance between the sensors. Therefore, the elastic modulus values of sugi (<i>Cryptomeria japonica</i>), hinoki (<i>Chamaecyparis obtusa</i>), akamatsu (<i>Pinus densiflora</i>), and karamatsu (<i>Larix kaempferi</i>), which have been used for wooden civil engineering structures, were evaluated while varying the sensor insertion position and the distance between sensors. The elastic modulus was found to be larger when the sensor was inserted between the structural member cross sections, rather than between the surfaces. Moreover, a positive correlation between elastic modulus and distance between sensors was discovered. Subsequently, a correction formula was devised that ensures that the elastic modulus is constant, regardless of sensor insertion position and distance between sensors, with the correction formula calculated for each of the examined wood species.</p>
◆Original paper【 display / non-display 】
◆International conference proceedings【 display / non-display 】
◆Research society, Symposium materials, etc.【 display / non-display 】
◆Other【 display / non-display 】
Grant-in-Aid for Scientific Research 【 display / non-display 】
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Grant-in-Aid for Scientific Research(C)
Project Year： 2023.04 - 2026.03
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Grant-in-Aid for Scientific Research(B)
Project Year： 2021.04 - 2025.03
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Grant-in-Aid for Scientific Research(C)
Project Year： 2020.04 - 2023.03
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Grant-in-Aid for Young Scientists(B)
Project Year： 2001.04 - 2003.03