AIJ Journal of Technology and Design
Online ISSN : 1881-8188
Print ISSN : 1341-9463
ISSN-L : 1341-9463
Volume 28, Issue 70
Displaying 1-50 of 95 articles from this issue
Materials and Construction
Structures
  • Akihiko OBATA, Naofumi TERAMOTO, Tetsuya NISHIDA
    2022 Volume 28 Issue 70 Pages 1131-1136
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    On March 11, 2011, an earthquake occurred off the Pacific coast of Tohoku. The tsunami caused by this earthquake resulted in severe and extensive damage to structures in northeastern Japan. Consequently, the establishment of safer design methods has become a matter of social responsibility. In this study, hydraulic tests were conducted using a hydraulics model. Next, a CFD simulation is also carried out, which is validated by a comparison of the results with the experimental ones. Finally, the characteristics of the tsunami forces acting on the isolated and grouped buildings were investigated based on the experimental and analytical results.

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  • Koichi MORITA, Takashi HASEGAWA
    2022 Volume 28 Issue 70 Pages 1137-1141
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In this paper, the damage state classification method based on machine learning is applied to a shaking table test data of a full-scale three-story steel frame. The following results are shown; 1) By machine learning using only the shaking table tests data, it is possible to estimate each damage state classification by linear discriminant analysis. 2) Acceleration data from response analysis as the training data and shaking table test data as the verification data are utilized for machine learning, and damage state classification can be estimated.

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  • Yasuhiro HAYASHI, Mina SUGINO
    2022 Volume 28 Issue 70 Pages 1142-1147
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Based on the analysis results of the seismic diagnosis design of traditional houses in Kyoto, it has been considered that the surface soil amplification factor indicated in the guidelines may be overestimated. In this paper, we have analyzed the soil model used in the calculation of the amplification factor in the guidelines and that used in the earthquake damage estimation in Kyoto. As a result, the former soil model is not adequate for Kyoto city area. In addition, the lower limit of 1.23 is sufficient for the amplification factor used in the seismic diagnosis of traditional houses.

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  • Yasuhiro HAYASHI, Mina SUGINO, Kazuki TANAKA
    2022 Volume 28 Issue 70 Pages 1148-1153
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In this paper, first, an approximation formula for the amplification factor of the surface soil is proposed. However, since most of the traditional houses are located on good soil condition, the lower limit of surface soil amplification factor 1.23 may be acceptable in reality. On the other hand, the large amplification sites are hardly related to the large shaking area during the Hanaore-fault-zone earthquake which is deeply related to the safety of traditional houses in Kyoto. We also pointed out that increase in bearing capacity of houses may increase the deformation response in case of pulse-like ground motion input.

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  • Takahito NAKAMURA, Takashi KATO, Shuhei KANEKO, Chou KEI, Masaru KIKUC ...
    2022 Volume 28 Issue 70 Pages 1154-1159
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    A new fail-safe braking device has been developed to protect seismically-isolated structures against ground motions caused by mega earthquakes. The purpose of the device is avoiding collision between superstructure and retaining wall in base isolation layer, and keeping superstructure within a minimum damage. A full-scale prototype fail-safe braking device was fabricated, and loading tests were carried out. Expected performance was exhibited in the test. Seismic response analysis was also conducted to confirm the effectiveness of the device.

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  • Kazuki WATAI, Tatsuhiko MAEDA, Takayuki SONE, Masashi YAMAMOTO, Naomi ...
    2022 Volume 28 Issue 70 Pages 1160-1165
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In this paper, we propose a damper with large deformation capacity in two directions using high damping rubber bearings (HDRs) as damping component. Damper unit and horizontal force transmission unit is joined by bearing-type joint, and the vertical force does not act on HDRs. Therefore, HDRs only support the weight of damper unit and deform bi-directional under almost zero compressive stress. We confirmed that the proposed damper act with intended by dynamic loading test using scaled specimen.

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  • Takahiro YAMASAKI, Mitsuhiro MIYAMOTO, Miku HAMAOKA, Riho HAYASHI, Mas ...
    2022 Volume 28 Issue 70 Pages 1166-1171
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    This study investigated seismic ground motion intensity to estimate the damage rates of low- and middle-rise RC buildings due to various earthquakes. It calculated the vulnerability functions of analytical models of RC buildings for earthquake motions with different spectral characteristics and evaluated the effects of earthquake motions with different spectral characteristics on vulnerability functions. The results confirmed that the average acceleration response spectrum of the periodic band corresponding to the primary natural period of the building can usually estimate the damage rates of low- and middle-rise RC buildings due to various earthquakes.

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  • Koki UCHIDA, Tetsuo YAMASHITA
    2022 Volume 28 Issue 70 Pages 1172-1177
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Two latticed cylinders of aluminum alloy were 3D-printed and axially compressed to cause elephant-leg buckling. The cylinders were composed of triangular and hexagonal grids. 3D scan was performed to specify the real dimensions of the manufactured cylinders. To perform FE analysis composed of beam-elements, center line-models were extracted from the 3D scanned model using the Rhinoceros+Grasshopper functions. Initial geometric imperfection was specified as well as actual section dimensions. FE analysis and strength evaluation was carried out for comparison and verification on the test results.

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  • Takara MUTO, Ken’ichi KAWAGUCHI
    2022 Volume 28 Issue 70 Pages 1178-1182
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Prestressed structure, getting reaction force from additional air-container, is called as Air-prestressed structure in this report. The aim of this report is to investigate fundamental mechanical properties in the axial direction, such as elasticity and loading capacity, through the vertical loading test, of air-prestressed cylindrical structure. Three prototypes, having different size and specifications, are tested and the results are reported. It was found that the top point of some specimens suddenly displaced in the horizontal direction under vertical load. The loading capacity of the prototype is calculated by an analytical solution, and compared to experimental result.

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  • Nobuhiko AKIYAMA, Shigeaki KAWAHARA, Masaki ONOTSUKA, Masahiro INAYAMA
    2022 Volume 28 Issue 70 Pages 1183-1188
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    The aim of this study is to establish the design method of a timber semi-rigid frame construction system composed with coupled glulam members jointed by screws with steel side plate and high-tensile bolts. In this paper, firstly we proposed the evaluation method for the out-of-plane bending characteristics of the coupled members with high joint properties on the end. Secondly, we conducted the full-scale out-of-plane bending test for the coupled glulam specimens to grasp the mechanical behaviors. We found that the experimental results showed good agreement with the calculations by the proposed method.

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  • Masato SHIMOYAMA, Yuji MIYAZU, Yujiro MIYATA, Takehiro WAKITA, Hiroki ...
    2022 Volume 28 Issue 70 Pages 1189-1194
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    This study aims to develop a knee-brace friction damper for mid-rise timber frame buildings. First, time history seismic response analysis was conducted to investigate the performance of the damper to improve the seismic performance of a four-story timber building. Then, static cyclic loading test on a beam-column joint with/without a prototype friction damper was carried out to verify the effectiveness of the damper. It is found that the damper mitigates slip behavior and increases equivalent viscous damping ratio and equivalent stiffness.

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  • Shuto SAITO, Takeshi ASAKAWA, Kentaro KATAYAMA, Hiro KAWAHARA, Daisuke ...
    2022 Volume 28 Issue 70 Pages 1195-1200
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Time history response analyses of horizontal hybrid wooden structures with RC core on one or both sides are conducted considering the elasto-plasticity of the wooden part with Wayne-Stewart model as hysteretic characteristics. Then, by comparing the results with the static elasto-plasticity analyses, the effects of amplification of wooden part and eccentricity are verified, and the consistency with the horizontal load-carrying capacity calculation, such as the setting of the structural characteristics factor DS, is confirmed to form a concrete background for the design of horizontal wooden structures.

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  • Yasuhiro ARAKI, Shoichi NAKASHIMA
    2022 Volume 28 Issue 70 Pages 1201-1205
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    The recent years have shown the demand for Cross-Laminated-Timber (CLT) with high stiffness and strength for use in CLT for walls and floors of mid-rise buildings. Moreover, the partial compression performance parallel to the outer layer grain of these layer configurations and strength grading is unclear. Partial compression performance is an indispensable material property for the construction of CLT structural analysis models. Therefore, this study reports the results of a compression test and the partial compression parallel for the outer layer grain test of an S90 5-layer 7-ply CLT in consideration of compression rigidity and the effect of additional length.

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  • Riho HAYASHI, Takahiro YAMASAKI, Mitsuhiro MIYAMOTO, Masatoshi OKADA, ...
    2022 Volume 28 Issue 70 Pages 1206-1211
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    After a large earthquake such as Nankai Trough Earthquake, it is important to quickly and quantitatively judge whether the disaster base office buildings are safe or not. In order to realize the judgement, it is necessary to estimate the relationship between the story deformation angle and the damage estimation index considering the structural characteristics of buildings. The objective of this study is to propose the method for constructing the damage estimation index and to verify its accuracy. It is shown that the proposed damage estimation index based on the plasticity ratio is in good agreement with the actual damage.

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  • Yasunori MIZUSHIMA, Kosaku MITSUHASHI
    2022 Volume 28 Issue 70 Pages 1212-1217
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    A staggered pre-cast RC wall system is proposed. The system can provide the flexibility of interior spaces and simplifications of constructions. To investigate the structural properties of the system, experiments using scaled specimens were carried out with varying the vertical load acting on the wall. The experimental results showed that the load capacity of the system could be evaluated by the sum of friction force on the connection area and dowel capacity of reinforcement bars. Non-linear finite element analysis was conducted, and the analysis was validated by the experimental results. The analytical results also supported the bearing mechanism.

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  • Noritaka MOROHASHI, Atsuhisa OGAWA
    2022 Volume 28 Issue 70 Pages 1218-1223
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Flexural shear properties of cast-in-place pile using low quality recycled aggregate concrete with vinylon fiber was examined. As the result, drying shrinkage cracks was generated in low quality recycled aggregate concrete cast-in-place pile. The load carrying capacity of the cast-in-place pile was increased by the vinylon fiver under flexural shear experiment. Both cast-in-place pile normal concrete and low quality recycled aggregate concrete, load carrying capacity maintained until final acting load.

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  • Tomokazu YOSHIOKA, Kosuke TAKEDA
    2022 Volume 28 Issue 70 Pages 1224-1229
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In this paper, lateral loading tests were conducted on a full-scale RC partial wall with a shear span ratio of 0.5, and the relationship between the area of concrete spalling or loss and the chord rotation was derived from test results. Furthermore, the pre-trained DNN model was fine-tuned to generate a detector that can accurately detect and measure the concrete spalling and loss on the painted surface of RC partial walls. Finally, it was confirmed that both of them can be used to evaluate the experienced chord rotation from seismic damage photographs of RC partial walls.

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  • Shoichi KISHIKI, Shotaro NAKADA, Miku KUROSAWA
    2022 Volume 28 Issue 70 Pages 1230-1235
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    A reconnaissance of steel school gymnasium damaged by the earthquake off the coast of Fukushima Prefecture on February 13, 2021 has been conducted. These gymnasiums were also damaged in the 2011 Tohoku earthquake, and have been repaired or strengthened. In the two gymnasiums, severe damage to non-structural components occurred again. It means that restoration to the original condition would have caused the damage to recur. In the other one, all of the additional braces for strengthening were fractured. It has the complicated structural system, indicates that how to repair or strengthen should be discussed more.

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  • Yuta FUKE, Taichiro OKAZAKI, Ryota MATSUI
    2022 Volume 28 Issue 70 Pages 1236-1241
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In-situ tests were conducted to examine the design service life of a steel-framed greenhouse composed of European components and situated in Sapporo city. Based on the measured force distribution, the allowable strength limit may be reached at a three-second gust speed of 24.5 m/s, which translates to a design life of 1.6 to 5.1 years, depending on the referenced design standard. The test bay deformed three times as much as prediction from elastic analysis. An analysis model that incorporated the flexibility of column bases and knee brace connections adequately reproduced the measured force distribution and deformation.

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  • Norihito TANIHARA, Yuuki Alejandro HOSAKA VENTURA, Masayuki KUROKI
    2022 Volume 28 Issue 70 Pages 1242-1247
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    In order to investigate the effect of middle tie beams on confined masonry walls, we conducted experiments of test specimens in which the variables were brick strength and the presence or absence of middle tie beam. In this paper, we report the effects of each parameter from the results obtained in the experiment. First, the test specimen composition and the experimental plan will be explained. The experimental results are shown below. Finally, from these results, a comparative examination is carried out.

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  • Mizuki HAMASAKI, Yukihiro MATSUMOTO, Takashi TAGUCHI, Keisuke SHIMIZU, ...
    2022 Volume 28 Issue 70 Pages 1248-1253
    Published: October 20, 2022
    Released on J-STAGE: October 20, 2022
    JOURNAL FREE ACCESS

    Turnbuckle braces buckle easily by the compressive load and the buckling deformation may lead to the damage of finishing material, plastic strain concentration and plastic fatigue failure. The authors have been developing a bracing system with a compression-free function using CFRP. This bracing system has a partially fibered CFRP to absorb the axial compressive deformation. In this paper, the mechanical characteristics of the braces system are investigated through full-scale tests under horizontal force loading.

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