研究者データベース
島本 由麻SHIMAMOTO Yumaしまもと ゆま
| ■所属部署名 | 農学研究院 農業環境工学部門 | |||
| ■職名 | 准教授 | |||
Last Updated :2025/01/22
業績情報
氏名・連絡先
氏名
しまもと ゆま, 島本 由麻, SHIMAMOTO Yuma
主たる所属・職名
農学研究院 農業環境工学部門, 准教授
その他の所属
学位
教育・研究活動状況
科学研究費助成事業
- 基盤研究（C）
鋼矢板水路の腐食実態の非破壊同定に基づく寿命評価法の開発
自 2023年, 至 2023年 - 国際共同研究加速基金（国際共同研究強化（B））
地震頻発国の相互協力によるパイプラインの非破壊損傷度評価法の開発
自 2023年, 至 2023年 - 若手研究
稲副産物「もみ殻」の活用によるCO2削減を考慮した農業基盤施設の寿命評価モデル構築
自 2023年, 至 2026年 - 基盤研究(C)
鋼矢板水路の腐食実態の非破壊同定に基づく寿命評価法の開発
自 2022年, 至 2022年 - 国際共同研究加速基金（国際共同研究強化(B)）
地震頻発国の相互協力によるパイプラインの非破壊損傷度評価法の開発
自 2022年, 至 2022年 - 基盤研究(C)
鋼矢板水路の腐食実態の非破壊同定に基づく寿命評価法の開発
自 2021年, 至 2021年 - 国際共同研究加速基金（国際共同研究強化(B)）
地震頻発国の相互協力によるパイプラインの非破壊損傷度評価法の開発
自 2021年, 至 2021年 - 若手研究
農村地域の持続的発展に質する稲副産物を活用した緑化基盤材の開発
自 2020年, 至 2022年
論文
- Frost damage evaluation of concrete irrigation structure by X-ray CT and AE energy release trend at the initial loading stage
Morozova, Nadezhda; Shibano, Kazuma; Shimamoto, Yuma; Tayfur, Sena; Alver, Ninel; Suzuki, Tetsuya
CASE STUDIES IN CONSTRUCTION MATERIALS
ELSEVIER
Deterioration of concrete infrastructures occurs for several reasons, leading to operational problems and further collapse. Freezing-thawing processes are one of the active damage mech-anisms in cold regions causing defect accumulation in the inner structure of the material and reduction of the mechanical properties. The optimal way to evaluate the damage degree is by applying non-destructive testing (NDT) methods which allow detailed and integrated results. In this research, a relationship between Acoustic Emission (AE) release energy trend and X-ray Computed Tomography (CT) parameters was investigated for damage quantification. Visualiza-tion and extraction of the internal concrete components were conducted by X-ray CT. The ul-trasonic pulse velocity (UPV) and resonant frequency methods were employed for the determination of the dynamic modulus of elasticity. After utilizing AE on the compression test, the damage characterization was evaluated. The extensive description of structural members in in-service structure was acquired using principal component analysis (PCA). The X-ray CT results show that all specimens have initial damage degrees in form of cracks and voids unevenly distributed within the concrete matrix. Regarding the irrigation structure, all concrete specimens have unique particle characteristics depending on which structural members they were drilled out from. Moreover, it is observed that the accumulated damage in the form of voids positively correlates with the initial AE energy release rate. In concrete specimens with low damage degrees, the AE energy release has an upward trend of low amplitude (<= 50 dB) with a silent stage at the initial loading and sudden release only near the final failure. In contrast, heavily damaged con-crete shows continuous AE energy release of high amplitude (>= 60 dB) and with a high initial AE energy release rate corresponding to the uninterrupted crack propagation and coalescence in the early stage of fracture and throughout the loading due to the high weak zones ratio. These results indicate that frost damage can be evaluated by the comprehensive analysis of the fracture process of concrete based on X-ray CT and AE results to characterize the damage degree.
2023年07月, 研究論文（学術雑誌）, 共同, 18, 2214-5095, DOI(公開)(r-map) - Influence of the Pre-Existing Defects on the Strain Distribution in Concrete Compression Stress Field by the AE and DICM Techniques
Morozova, Nadezhda; Shibano, Kazuma; Shimamoto, Yuma; Suzuki, Tetsuya
APPLIED SCIENCES-BASEL
MDPI
This research investigates the influence of the pre-existing defects within concrete taken from the in-service irrigation structure on the strain distribution. The X-ray Computed Tomography (CT) technique is employed to investigate the internal concrete matrix and evaluate the defect distribution in it. The cracking system in a concrete matrix is detected as a damage type caused by the severe environment, and it is varied by the different degrees in all samples. The geometric properties of defects and their spatial location are obtained by image processing of CT images. The compression test with Acoustic Emission (AE) and Digital Image Correlation (DIC) measurements is conducted to analyze the fracture processes and acquire the damage spatial information. The AE signal descriptors are effective parameters for real-time detection and potential local damage monitoring. Moreover, the analysis of the DICM strain and displacement fields reveals the most potential fracture zones. The AE source location analysis indicated a connection between pre-existing defects and strain localization. The AE events and strain are high in the defect areas. Additionally, the amplitude and frequency of the AE events correlated with the location of the defects indicating that the structure weakness at that point leads to concentrated deformation development.
2023年05月31日, 研究論文（学術雑誌）, 共同, 13, 11, DOI(公開)(r-map) - Identifying effective AE parameters for damage evaluation of concrete in headwork: a combined cluster and random forest analysis of acoustic emission data
Shimamoto, Yuma; Tayfur, Sena; Alver, Ninel; Suzuki, Tetsuya
PADDY AND WATER ENVIRONMENT
SPRINGER HEIDELBERG
Agricultural concrete structures are damaged by environmental factors. To maintain such structures, it is necessary to properly determine the mechanical properties and degree of damage suffered by concrete using core tests. In previous studies, the degree of damage has been evaluated by acoustic emissions (AE) detected in compressive stress fields. The process of fracture in damaged concrete has been evaluated by analyzing various AE parameters such as AE hits, energy, and frequency. The usefulness of many AE parameters for evaluating the fracture process is evident, but the most effective AE parameters have not yet been identified. In this study, the relationship between the stress level of concrete under compression and AE parameters was investigated using regression analysis with random forests to identify the most important AE parameters. Whether the accuracy of the regression analysis could be improved by clustering AE waves was also investigated. For this purpose, core samples, severely damaged by frost, were drilled out from a concrete headwork and subjected to compressive strength tests using the AE method. After monitoring the uniaxial compression tests, statistics for seven AE parameters were calculated for every 20 x 10(-6) increment of strain. Then, AE waves were classified into three clusters based on three parameters: peak amplitude, peak frequency, and centroid frequency. The accuracy of the regression analysis was compared using non-clustered and clustered data. The peak frequencies of cluster 1 and cluster 3 were significantly higher than that of cluster 2. This result suggests that cluster 1 and cluster 3 can be attributed to macro- or mezzo-scale damage. The regression analysis' results showed that R-2 was higher (0.720 as compared to 0.620), and RMSE and MAE were lower in cluster 1 and cluster 3 (high-peak-frequency clusters) than in non-clustered cases. Therefore, cluster analysis can be expected to improve the accuracy of AE testing. Finally, the importance of AE parameters using random forests was calculated. The most important parameter was determined to be rise time, and the second was the centroid frequency. These results suggest that these two parameters can be used to clarify compressive fracture behavior of damaged concrete.
2023年01月, 研究論文（学術雑誌）, 共同, 21, 1, 1611-2490, DOI(公開)(r-map), 15, 29 - Non-contact detection of degradation of in-service steel sheet piles due to buckling phenomena by using digital image analysis with Hough transform
Frontiers in Built Environment
2022年08月, 研究論文（学術雑誌）, DOI(公開)(r-map) - Visualization and evaluation of concrete damage in-service headworks by X-ray CT and non-destructive inspection methods
Frontiers in Built Environment
2022年08月, 研究論文（学術雑誌）, DOI(公開)(r-map)
受賞
- 公益財団法人 農学会
公益財団法人農学会 日本農学進歩賞
農業副産物を活用した環境親和性材料の創出と非破壊試験法の開発
人類と多様な生態系が永続的に共生するための基盤である農林水産業およびその関連産業の発展に資するため、農学の進歩に顕著な貢献をした者に授与される。
2023年11月24日 - International Society of Paddy and Water Environment Engineering (PAWEES)
International Society of Paddy and Water Environment Engineering (PAWEES) Young Professional Award
This Award was recommended by Taiwanese Agricultural Engineering Society, in order to encourage young researchers who will be leaders of PAWEES in the future and stimulate research mind about paddy and water environment among young researchers, and prize was donated by the Taiwanese Society.
2023年10月24日 - 農業農村工学会
農業農村工学会 研究奨励賞
農業農村工学へのAcoustic Emission法の応用と機械学習による精度向上に関する?連の研究
農業農村工学に関する学術又は技術の進歩に寄与すると認められる優秀な業績をあげた個人に授与される。
2022年08月30日