| TOMOAKI UTSUNOMIYA | Last modified date：2024.04.19 |
Professor /
Marine Systems Design /
Department of Marine Systems Engineering /
Faculty of Engineering
Papers
| 1. | Tomoaki Utsunomiya, Hisashi Okubo, Hiroto Yamada, Development of a Simulation Tool for Floating Offshore Wind Turbines Using MBDyn, Proceedings of the Third World Conference on Floating Solutions, 2024.06. |
| 2. | Ryoya Hisamatsu, Tomoaki Utsunomiya, Floating OTEC Plant – A Design and Coupled Dynamics, Proceedings of the Third World Conference on Floating Solutions, 2024.06. |
| 3. | Koji Tanaka, Atsuhiro Iwamoto, Tomoaki Utsunomiya, Comparison of dynamic response of a 2-MW hybrid-spar floating offshore wind turbine during power production using full-scale field data, Grand Renewable Energy 2022 International Conference, https://doi.org/10.24752/gre.2.0_42, 2022.12. |
| 4. | Yogie Muhammad Lutfi, Ristiyanto Adiputra, Aditya Rio Prabowo, Tomoaki Utsunomiya, Erwandi Erwandi, Nurul Muhayat, Assessment of the stiffened panel performance in the OTEC seawater tank design: Parametric study and sensitivity analysis, Theoretical and Applied Mechanics Letters, https://doi.org/10.1016/j.taml.2023.100452, 13, 2023.04. |
| 5. | Ryoya Hisamatsu, Tomoaki Utsunomiya, Free vibration and stability of a fully submerged pipe aspirating water: An experiment and new physical insights, Journal of Fluids and Structures, https://doi.org/10.1016/j.jfluidstructs.2022.103789, 116, 2023.01, Dynamic stability due to internal axial flow is a considerable problem for a pipe conveying fluid such as deep seawater intaking for an Ocean Thermal Energy Conversion (OTEC) plant. However, there has been much ambiguity about its dynamics, and this raises a question about whether such an aspirating pipe submerged in water flutters or not. Therefore, the objective of this paper is to provide an experiment to take a new look at the dynamics of pipe aspirating fluid (water). The experimental apparatus is constructed to eliminate expected disturbances, and we measure free damped vibrations of a submerged 4 m length pipe with internal flow. As a result, we observe the nonlinear and non-planar behavior, however, the pipe converges to the zero point and remains stable at a maximum velocity of 1.66 m/s. Subsequently, we review existing theoretical models, and present a comparison with the results from the tank experiment. In addition, we provide a new model of the inlet flow field, which plays an important role on stability, considering the flow separation and jet formed inside of the pipe entrance. This equation is solved by FEM for time integration and eigenvalue analysis, and the results seem to reproduce the experimental natural period and amplitude of the free vibration with internal flow. The model also suggests that an aspirating pipe submerged in water does not flutter up to the maximum flow velocity attainable in the experiment.. |
| 6. | Ryoya Hisamatsu, Tomoaki Utsunomiya, Dynamics of a cold water intaking pipe subject to internal flow and motion excitation, ASME 2023 42nd International Conference on Ocean, Offshore and Arctic Engineering, 2023.06. |
| 7. | Ryoya Hisamatsu, Ristiyanto Adiputra, Tomoaki Utsunomiya, Experimental Study on Dynamic Characteristics of Fluid‑conveying Pipe for OTEC, ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2022‑78136, 2022.10. |
| 8. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Finite Element Modelling of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP), ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2022‑78135, 2022.10. |
| 9. | Ryoya Hisamatsu, Tomoaki Utsunomiya, Coupled response characteristics of cold water pipe and moored ship for floating OTEC plant, Applied Ocean Research, https://doi.org/10.1016/j.apor.2022.103151, 123, 2022.04, [URL], A floating Ocean Thermal Energy Conversion (OTEC) plant requires a large-diameter Cold Water Pipe (CWP) to be attached to a floating structure. For the design of the mooring system and the CWP, a coupled analysis of a floating body, mooring system and CWP should be employed due to the huge mass of the internal fluid in the CWP. The aim of this paper is to construct a simplified coupled response model to facilitate the preliminary stage of the design. The equations of equilibrium and motion are derived based on modeling as a two-dimensional floating body and an elastic pendulum. In order to verify the applicability for a practical design and limitation of the present model, a 100 MW ship-shaped platform, a spread mooring system and a CWP with an inner diameter of 12 m and a length of 800 m are configured. The results of the extreme analysis in the frequency domain with equivalent linearization of drag force by using the present model agree well with the time domain coupled analysis using OrcaFlex. Subsequently, the influence of the design parameters for CWP to the coupled responses is also clarified by a parametric study combining the bending stiffness, the linear density and the boundary conditions. The proposed model will facilitate the preliminary study with a large number of design trials, and a comprehension of the results of numerical simulations and model experiments.. |
| 10. | Ryoya Hisamatsu, Tomoaki Utsunomiya, Simplified Formulation of Coupled System Between Moored Ship and Elastic Pipe for OTEC Plantship, ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2021-62122, 2021.10, A floating Ocean Thermal Energy Conversion (OTEC) plant requires a large-diameter Cold Water Pipe (CWP) to be attached to a floating structure. For the design of the mooring system and the CWP, a coupled analysis of a floating body, mooring system and CWP should be employed due to the huge mass of the internal fluid in the CWP. The aim of this paper is to construct a simplified coupled response model to facilitate the preliminary stage of the design. The equations of equilibrium and motion are derived based on modeling as a two-dimensional floating body and an elastic pendulum. In order to verify the applicability for a practical design and limitation of the present model, a 100 MW ship-shaped platform, a spread mooring system and a CWP with an inner diameter of 12 m and a length of 800 m are configured. The results of the extreme analysis in the frequency domain with equivalent linearization of drag force by using the present model agree well with the time domain coupled analysis using OrcaFlex. Subsequently, the influence of the design parameters for CWP to the coupled responses is also clarified by a parametric study combining the bending stiffness, the linear density and the boundary conditions. The proposed model will facilitate the preliminary study with a large number of design trials, and a comprehension of the results of numerical simulations and model experiments.. |
| 11. | Takaaki Takeuchi, Tomoaki Utsunomiya, Koji Gotoh, Iku Sato, Development of Simplified Wear Estimation Method Considering Rolling Motion Between Mooring Chain Links for Floating Structures, ASME 2021 40th International Conference on Ocean, Offshore and Arctic Engineering, https://doi.org/10.1115/OMAE2021-62574, 2021.10. |
| 12. | , [URL]. |
| 13. | Takeuchi, T., Utsunomiya, T., Gotoh, K., & Sato, I., Development of interlink wear estimation method for mooring chain of floating structures: Validation and new approach using three-dimensional contact response, Marine Structures, https://doi.org/10.1016/j.marstruc.2020.102927, 77, 2021.05, [URL], Long-term operation of mooring systems is one of the challenging issues of floating structures such as floating offshore wind turbines (FOWTs). For integrity assessment, fatigue and its affecting factors have generated considerable recent research interest as the occurrence of a large number of mooring chain failures at a high rate has been reported. By contrast, only few studies on the effect of nonuniform volume loss of mooring chain links due to wear can be found because of difficulties to estimate wear amounts quantitatively. Considering this issue, in this paper, validation of the quantitative interlink wear estimation method is investigated by applying to a spar-type floating structure. Firstly, the method is presented which consists of the material test, derivation of an interlink wear estimation formula with FE analysis, and calculation of mooring chain response with coupled dynamic analysis using a mass-spring model. To improve insufficient accuracy due to the mass-spring model around a clump weight and the touchdown point, the method is further modified by using a 3-D rigid-body link model. The estimation results and comparison show that the modified method distinguishing between rolling and sliding can calculate the interlink wear amount closer to the chain diameter measurements and more reasonable than the method using the conventional mass-spring model.. |
| 14. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Linear vs non-linear analysis on self-induced vibration of OTEC cold water pipe due to internal flow, Applied Ocean Research, https://doi.org/10.1016/j.apor.2021.102610, 110, 2021.03, [URL], This paper presents analytical and numerical analyses on self-induced vibration of Ocean Thermal Energy Conversion (OTEC) Cold Water Pipe (CWP) for a 100 MW-net OTEC power plant. The CWP is described as a vertically-hanged, top-tensioned riser subjected to internal flow effect (IFE) and ambient fluid effects (added mass and drag force). In the analytical analysis, two definitions of the drag force equation in the frequency-domain term and time-domain term are considered yielding a linear differential equation and a non-linear differential equation. The stability is assessed by discretizing the equations using Frobenius method and Galerkin Method and then plotting its eigenfrequencies or its eigenvalues in an Argand diagram. Separately, a fully-coupled fluid-structure interaction is carried out in a numerical simulation for particular cases. The scantlings of the riser are chosen from the available size of Fiber Reinforced Plastic (FRP) pipe in a manufacturer and varied accordingly for future production capacity development. The riser is pinned at the top and mounted at the bottom. Results indicate that the predicted critical velocity in the time domain is averagely 20% higher compared to the frequency domain. The effect of the clump weight on the critical velocity is more significant for light material compared with relatively high-density material.. |
| 15. | Kakuya, H., Yoshida, S., Sato, I. & Utsunomiya, T., A study on the platform-pitching vibration of floating offshore wind turbines based on classical control theory, Wind Engineering, https://doi.org/10.1177/0309524X19862761, 44, 6, 610-630, 2020.10. |
| 16. | Kakuya, H., Yoshida, S., Sato, I. & Utsunomiya, T., Proposal for a lower limit control of a generator’s torque based on the nacelle wind speed and demonstration results using a full-scale spar-type floating offshore wind turbine, Wind Engineering, https://doi.org/10.1177/0309524X19862754, 44, 6, 645-660, 2020.10. |
| 17. | Takaaki Takeuchi, Tomoaki Utsunomiya, Koji Gotoh, Iku Sato, Quantitative wear estimation for floating structures by using 3-D geometry of mooring chain, ASME 2020 39th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2020, https://doi.org/10.1115/OMAE2020-18409, OMAE2020-18409, 2020.08, [URL]. |
| 18. | Koji Tanaka, Iku Sato, Tomoaki Utsunomiya, Hiromu Kakuya, Validation of dynamic response of a 2-MW hybrid-spar floating wind turbine during typhoon using full-scale field data, Ocean Engineering, 10.1016/j.oceaneng.2020.108262, 218, 2020.10, Accurate estimation of the dynamic behavior of Floating Offshore Wind Turbines (FOWTs) under typhoon environment is essential to design and install FOWTs in a prone area of typhoons such as around Japan. Up to now, extensive efforts for development of design tools for FOWTs have been made, and nowadays several design tools are available. Needless to say, it is of utmost importance that the engineering design tools have been verified and validated for the real physical phenomena before being applied to real designs/projects with confidence. Much efforts have thus been made as code-to-code comparisons and by validations using model test data. Validations of the design tools using full-scale field data for FOWTs have also been made, but available open literatures are quite limited, particularly for design-driving extreme cases. In this paper, we describe the analysis of the dynamic response of a 2-MW spar-type FOWT at the time of typhoon attack in the actual sea area. The central atmospheric pressure of the typhoon at the closest time was 965 hPa, the maximum instantaneous wind speed at the hub height was 52.2 m/s, and the maximum significant wave height was 6.9 m. The dynamic responses under the typhoon environment are numerically simulated by using the time-series records of the wind speed, the wind direction, the wave height, the wave direction, the current speed, and the current direction which were acquired during the typhoon passing through close to the FOWT. Then the simulated motion responses are compared with the measured motion responses for the same durations. By the comparisons, the numerical simulation tool which was used for the design of the FOWT has been partially validated. It has also been confirmed that the spatial coherence of the wind speed has a significant effect for the platform motions, particularly for yaw motion.. |
| 19. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Stability based approach to design cold-water pipe (CWP) for ocean thermal energy conversion (OTEC), Applied Ocean Research, 10.1016/j.apor.2019.101921, 92, 2019.11, Cold-water pipe (CWP) is a novel, most-challenging component of Ocean Thermal Energy Conversion (OTEC) floating structure which is installed to transport the deep seawater to the board. For commercial scale, the transported seawater flow rate will be in the order of 10^2 m^3/s. This large amount of internal flow may trigger instability which leads to the failure of CWP. Considering this issue, the present paper aims to design commercial-scale OTEC CWP focusing on the effects of internal flow to the stability of the pipe. The design analysis is deliberated to select the pipe material, top joint configuration (fixed, flexible, pinned) and bottom supporting system (with and without clump weight). Initially, the analytical solution is built by taking into account the components of the pipe dynamics. Separately, a fully coupled fluid-structure interaction analysis between the pipe and the ambient fluid is carried out using ANSYS interface. Using scale models, the results obtained from the analytical solution are compared with the ones from numerical analysis to examine the feasibility of the analytical solution. After being verified, the analytical solution is used to observe the dynamic behavior of the CWP for 100 MW-net OTEC power plant in the full-scale model. The results yield conclusions that pinned connection at the top joint is preferable to decrease the applied stress, clump weight installation is necessary to reduce the motion displacement and Fiber Reinforced Plastic (FRP) is the most suitable material among the examined materials.. |
| 20. | Koki IKEDA, Ristiyanto ADIPUTRA, Tomoaki UTSUNOMIYA, Preliminary Design of a Cold Water Pipe for OTEC Application, TEAM 2019, Oct. 14 - 17, 2019, Tainan, Taiwan, 2019.10. |
| 21. | Ryoya HISAMATSU, Ristiyanto ADIPUTRA, Tomoaki UTSUNOMIYA, Motion Simulation and Mooring Design of an OTEC Plantship, TEAM 2019, Oct. 14 - 17, 2019, Tainan, Taiwan, 2019.10. |
| 22. | Tomoaki Utsunomiya, Irregular Frequency Removal and Convergence in Higher‑order BEM for Wave Diffraction/Radiation Analysis, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-95482, 2019.06. |
| 23. | Koji Gotoh, Tetsuya Ueda, Koji Murakami, Tomoaki Utsunomiya, Wear Performance of Mooring Chain in Wet Environment with Substitute Ocean Water, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-95822, 2019.06.  |
| 24. | Takaaki Takeuchi, Tomoaki Utsunomiya, Koji Gotoh, Iku Sato, Quantitative Wear Estimation for Mooring Chain of Floating Structures and its Validation, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-96750, 2019.06. |
| 25. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Stability Analysis of Free Hanging Riser Conveying Fluid for Ocean Thermal Energy Conversion (OTEC) Utilization, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-96749, 2019.06. |
| 26. | Tomoaki Utsunomiya, Iku Sato, Koji Tanaka, At‑sea Experiment on Durability and Residual Strength of Polyester Rope for Mooring of Floating Wind Turbine, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-95388, 2019.06. |
| 27. | Koji Tanaka, Iku Sato, Tomoaki Utsunomiya, Hiromu Kakuya, Comparison of Dynamic Response in a 2MW Floating Offshore Wind Turbine during Typhoon Approaches, ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2019, OMAE2019-95889, 2019.06. |
| 28. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Jaswar Koto, Takeshi Yasunaga, Yasuyuki Ikegami, Preliminary design of a 100 MW-net ocean thermal energy conversion (OTEC) power plant study case: Mentawai island, Indonesia, Journal of Marine Science and Technology, https://doi.org/10.1007/s00773-019-00630-7, 2019.02, Ocean thermal energy conversion is one of the promising renewable energy resources yet relatively unexplored due to its high capital cost for being utilized in commercial scale. In the aim to reduce the capital cost, this paper introduces a concept design of the floating structure from a converted oil tanker ship. To propose the design process, the general principles of designing a converted tanker FPSO is adapted and then modified to deal with ocean thermal energy conversion (OTEC) characteristic. In the design process, the arrangement of the OTEC layout is carried out by constraint satisfaction method and the prospective floating structure size is varied using Monte Carlo simulation. The variables in the design process consist of the velocities of cold water and warm water transport, the size of the plantship, and the location of the OTEC equipment to the seawater tank. Constraints are introduced as allowable border to determine the acceptability for particular case including the provided space and buoyancy, and the net power output estimation. The results show that the ‘typical’ size of a Suezmax oil tanker ship is the optimum one for the plantship with the velocity of the water transport of 2–3 m/s. The general arrangement is also conceptualized in this paper.. |
| 29. | Utsunomiya, T., Sato, I., Kobayashi, O., Shiraishi, T., Harada, T., Numerical Modeling and Analysis of a Hybrid-Spar Floating Wind Turbine, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4041994, 141, 3, 031903-1-031903-5, 2019.01. |
| 30. | Hiromu Kakuya, Shigeo Yoshida, Iku Sato, Tomoaki Utsunomiya, A study on the platform-pitching vibration of floating offshore wind turbines based on classical control theory, Wind Engineering, 10.1177/0309524X19862761, 2019.01, One of the issues of floating offshore wind turbines is the platform-pitching vibration generated by the blade pitch angle motion of the variable speed control. This study investigated the platform-pitching vibration based on the classical control theory using a transfer function between the generator speed and the nacelle pitch angle. This study also investigated the impact of the floating platform vibration control, which can suppress the vibration by adjusting the blade pitch angle according to the nacelle pitch angle, by using a transfer function to which floating platform vibration control is added. The stabilities of these transfer functions were determined using the Nyquist stability criterion, and the impact of the floating platform vibration control parameters was investigated using Bode diagrams.. |
| 31. | Hiromu Kakuya, Shigeo Yoshida, Iku Sato, Tomoaki Utsunomiya, Proposal for a lower limit control of a generator’s torque based on the nacelle wind speed and demonstration results using a full-scale spar-type floating offshore wind turbine, Wind Engineering, 10.1177/0309524X19862754, 2019.01, Among the issues of floating offshore wind turbines are the platform-pitching vibrations generated by blade pitch angle motions of the variable speed control. Control of blade pitch angle based on the platform-pitching motion (floating platform vibration control) can suppress these vibrations. This study investigates the impact of floating platform vibration control on variable speed control and the generator torque control, which control interferences cause the fluctuation of generator speed and platform-pitching angle at the transition region between below and above rated operating conditions. This study also proposes a new control to reduce the impact; in this method, the lower limit of generator torque is adjusted linearly depending on the nacelle wind speed, and the conventional feedback control for the generator torque mainly adjusts the generator torque. Simulation and demonstration results using a full-scale spar-type FOWT showed that the proposed method can stabalize suppress the fluctuations of generator speed, platform-pitching angle, and power at the transition region.. |
| 32. | Keisuke TERADA, Tomoaki UTSUNOMIYA, Jun OHNO, Study on safety assessment of jack-up type working platform for offshore wind turbine facilities, Proceedings of the 32nd Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures, Wuhan, China, 15-18 October 2018, 240-244, 2018.10. |
| 33. | Kazuki YAMANE, Masataka NAKAGAWA, Tomoaki UTSUNOMIYA, Koji GOTOH, Investigation on specific wear amount of mooring chain by pin-on-disk wear test, Proceedings of the 32nd Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures, Wuhan, China, 15-18 October 2018, 245-251, 2018.10. |
| 34. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Optimization Study on Floating Structure and Risers Design for a 100 MW-Net Ocean Thermal Energy Conversion (OTEC) Power Plant, Proceedings of the 4th Asian Wave and Tidal Energy Conference (AWTEC 2018), Sep. 9-13, 2018, Taipei, Taiwan, 2018.09. |
| 35. | Jian Dai, Chien Ming Wang, Tomoaki Utsunomiya, Wenhui Duan, Review of recent research and developments on floating breakwaters, Ocean Engineering, https://doi.org/10.1016/j.oceaneng.2018.03.083, 158, 132-151, 2018.06. |
| 36. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Design optimization of floating structure for a 100 MW-net ocean thermal energy conversion (OTEC) power plant, ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2018 Ocean Renewable Energy, 10.1115/OMAE2018-77539, 10, 2018.06. |
| 37. | Koji Gotoh, Masataka Nakagawa, Koji Murakami, Tomoaki Utsunomiya, Effect of tensile force for wear performance of mooring chain, ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2018
Materials Technology, 10.1115/OMAE2018-77960, 4, 2018.06. |
| 38. | Sho Oh, Tomoaki Utsunomiya, Kota Saiki, On-site measurement and numerical modelling of a lifting operation for caissons using floating crane, ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2018 Ocean Space Utilization, 10.1115/OMAE2018-77132, 6, 2018.06. |
| 39. | K. Kita, T. Utsunomiya, K. Sekita, Centrifuge model tests on holding capacity of suction anchors in sandy deposits, 9th International Conference on Physical Modelling in Geotechnics, ICPMG 2018 Physical Modelling in Geotechnics, 10.1201/9780429438660-107, 713-717, 2018.01, Holding capacity of suction anchor was studied by centrifuge model tests, in view of their application to the mooring system for floating wind power generation in offshore Japan. Capped stainless steel pipes placed in loose sandy deposits were pulled at about mid depth of the anchor embedment in nearly horizontal direction (initial angle of elevation of 12.5 to 23.7 degrees) under 20G centrifugal conditions. Measured holding capacities were compared with capacities estimated from a limit equilibrium model considering Reese type failure mechanism, as well as from a practical method proposed by Deng and Carter, both of which were associated with friction angles evaluated from centrifugal miniature cone penetration tests carried out prior to the anchor placement. Capacities predicated by Deng and Carter method underestimated measured ones.. |
| 40. | Hiromu Kakuya, Takashi Shiraishi, Shigeo Yoshida, Tomoaki Utsunomiya, Iku Sato, Experimental results of floating platform vibration control with mode change function using full-scale spar-type floating offshore wind turbine, Wind Engineering, https://doi.org/10.1177/0309524X17737336, 42, 3, 230-242, 2017.10. |
| 41. | Masataka Nakagawa, Koji Gotoh, Koji Murakami and Tomoaki Utsunomiya, A Study on the Wear Performance of the Mooring Chain for Floating Wind Turbine, Proceedings of the 31st Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures, Osaka, Japan, 25-28 September 2017, 2017.09. |
| 42. | Takaaki Takeuchi, Tomoaki Utsunomiya, Kimihiro Toh, Koji Gotoh, Development of Wear Estimation Method for Mooring Chain of Floating Structures, Proceedings of the 31st Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures, Osaka, Japan, 25-28 September 2017, 2017.09. |
| 43. | Ristiyanto Adiputra, Tomoaki Utsunomiya, Preliminary Design of an 100 MW Ocean Thermal Energy Conversion (OTEC) Power Plant in Indonesia, Proceedings of the 31st Asian-Pacific Technical Exchange and Advisory Meeting on Marine Structures, Osaka, Japan, 25-28 September 2017, 2017.09. |
| 44. | Koji Gotoh, Koji Murakami, Masataka Nakagawa and Tomoaki Utsunomiya, Wear Performance of the Mooring Chain Used in Floating Wind Turbines, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62195, 2017.06. |
| 45. | Tomoaki Utsunomiya, Kinji Sekita, Katsutoshi Kita and Iku Sato, Demonstration Test for Using Suction Anchor and Polyester Rope in Floating Offshore Wind Turbine, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62197, 2017.06. |
| 46. | Tomoaki Utsunomiya, Iku Sato, Osamu Kobayashi, Takashi Shiraishi and Takashi Harada, Numerical Modelling and Analysis of a Hybrid-Spar Floating Wind Turbine, Proceedings of the ASME 2017 36th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2017-62578, 2017.06. |
| 47. | T. UTSUNOMIYA, K. GOTOH, K. KITA, I. SATO, H. TAKANO, T. IWASHITA, At-sea Demonstration Test for Cost-reduction of Mooring System for Floating Wind Turbine, Proceedings of WWEC2016, 2016.11. |
| 48. | K. GOTOH, K. MURAKAMI, M. NAKAGAWA, T. UTSUNOMIYA, Experimental Study on the Wear Performance of the Mooring Chain, Proceedings of 7th PAAMES and AMEC2016, 2016.10. |
| 49. | T. UTSUNOMIYA, I. SATO, O. KOBAYASHI, T. SHIRAISHI, T. HARADA, Design and Installation of a Hybrid-Spar Floating Wind Turbine Platform, Proceedings of the ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering, 10.1115/OMAE2015-41544, 2015.05. |
| 50. | Tomoaki Utsunomiya, Takashi Shiraishi, Iku Sato, Etsuro Inui, Shigesuke Ishida, Floating offshore wind turbine demonstration project at Goto Islands, Japan, OCEANS 2014 MTS/IEEE Taipei Conference: Oceans Regeneration OCEANS 2014 - TAIPEI, 10.1109/OCEANS-TAIPEI.2014.6964595, 2014.11, Offshore wind energy resources in Japanese EEZ (Exclusive Economic Zone) are now considered to be huge. In order to utilize the huge amount of energy located in relatively deep water areas, Ministry of the Environment, Japan has kicked-off the demonstration project on floating offshore wind turbine (FOWT). The project will continue for six years beginning from 2010fy to 2015fy. In the project, two FOWTs have been installed. The first FOWT mounts a 100kW wind turbine of downwind type, and the length dimensions are almost half of the second FOWT (so called as 1/2 scale model). The second FOWT mounts a 2MW wind turbine of downwind type, and called as a full scale model. The FOWTs consist of PC-steel hybrid spar (which is cost-effective) and are moored by three mooring chains. The half scale model was installed at the site on 11 June 2012 as the first grid-connected FOWT in Japan. The half scale model was attacked by very severe typhoon Sanba (1216), the greatest tropical typhoon in 2012 in the world. The behavior during the typhoon attack, including the measured environmental data and the FOWT responses is introduced. The installation of the full scale model has also successfully been made. The installation at the site completed on 18 October 2013; as the first multi-megawatt FOWT in Japan. The installation procedures and current status are also presented.. |
| 51. | T. UTSUNOMIYA, S. YOSHIDA, H. OOKUBO, I. SATO, S. ISHIDA, Dynamic analysis of a floating offshore wind turbine under extreme environmental conditions, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4025872, 136, 2, 020904, 2014.03, [URL]. |
| 52. | K. SHIBANUMA, T. UTSUNOMIYA, S. AIHARA, An explicit application of partition of unity approach to XFEM approximation for precise reproduction of a priori knowledge of solution, International Journal for Numerical Methods in Engineering, 10.1002/nme.4593, 97, 8, 551-581, 2014.02. |
| 53. | Hajime Mase, Tomohiro Yasuda, Nobuhito Mori, Tracey H.A. Tom, Ai Ikemoto, Tomoaki Utsunomiya, Analysis and forecasting of winds and waves for a floating type wind turbine, 34th International Conference on Coastal Engineering, ICCE 2014 Proceedings of the 34th International Conference on Coastal Engineering, ICCE 2014, 2014.01, The floating type wind turbine demonstration project has been promoted in Japan. In 2012, a 1:2 scale model was installed off Kabashima Island in Nagasaki Prefecture. And a year later, a full scale model was installed. For the design of the wind turbine's floating body, winds, waves and other parameters were analyzed. For the construction and daily management, a prediction system was developed and the predictions and observations of winds and waves were compared and the agreement between them was good.. |
| 54. | Tomoaki Utsunomiya, Shigeo Yoshida, Soichiro Kiyoki, Iku Sato, Shigesuke Ishida, Dynamic response of a spar-type floating wind turbine at power generation, ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2014 Ocean Space Utilization; Professor Emeritus J. Randolph Paulling Honoring Symposium on Ocean Technology, 10.1115/OMAE2014-24693, 2014.01, In this paper, dynamic response of a Floating Offshore Wind Turbine (FOWT) with spar-type floating foundation at power generation is presented. The FOWT mounts a 100kW wind turbine of down-wind type, with the rotor's diameter of 22m and a hub-height of 23.3m. The floating foundation consists of PC-steel hybrid spar. The upper part is made of steel whereas the lower part made of prestressed concrete segments. The FOWT was installed at the site about 1km offshore from Kabashima Island, Goto city, Nagasaki prefecture on June 11th, 2012. Since then, the field measurement had been made until its removal in June 2013. In this paper, the dynamic behavior during the power generation is presented, where the comparison with the numerical simulation by aero-hydroservo- mooring dynamics coupled program is made.. |
| 55. | Tomoaki Utsunomiya, Iku Sato, Shigeo Yoshida, Hiroshi Ookubo, Shigesuke Ishida, Dynamic response analysis of a floating offshore wind turbine during severe typhoon event, ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2013 ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering, OMAE 2013, 10.1115/OMAE2013-1061, 2013.12, In this paper, dynamic response analysis of a Floating Offshore Wind Turbine (FOWT) with Spar-type floating foundation is presented. The FOWT mounts a 100kW downwind turbine, and is grid-connected. It was launched at sea on 9th June 2012, and moored on 11th for the purpose of the demonstration experiment. During the experiment, the FOWT was attacked by severe typhoon events twice. Among them, Sanba (international designation: 1216) was the strongest tropical cyclone worldwide in 2012. The central atmospheric pressure was 940 hPa when it was close to the FOWT, and the maximum significant wave height of 9.5m was recorded at the site. In this paper, the dynamic responses of the platform motion, the stresses at the tower sections and the chain tensions during the typhoon event, Sanba (1216), have been analyzed, and compared with the measured data. Through the comparison, validation of the numerical simulation tool (Adams with SparDyn developed by the authors) has been made.. |
| 56. | T. UTSUNOMIYA, H. MATSUKUMA, S. MINOURA, K. KO, H. HAMAMURA, O. KOBAYASHI, I. SATO, Y. NOMOTO, K. YASUI, At-sea experiment of a hybrid spar for floating offshore wind turbine using 1/10-scale model, Journal of Offshore Mechanics and Arctic Engineering, ASME, 10.1115/1.4024148, 135, 3, 034503, 2013.08. |
| 57. | Ishida, S., Kokubun, K., Nimura, T., Utsunomiya, T., Sato, I., Yoshida, S., AT-SEA EXPERIMENT OF A HYBRID SPAR TYPE OFFSHORE WIND TURBINE, PROCEEDINGS OF THE ASME 32ND INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING - 2013 - VOL 8, 10.1115/OMAE2013-10655, V008T09A035, 2013.06. |
| 58. | Utsunomiya, T., Sato, I., Yoshida, S., Ookubo, H., Ishida, S, DYNAMIC RESPONSE ANALYSIS OF A FLOATING OFFSHORE WIND TURBINE DURING SEVERE TYPHOON EVENT, PROCEEDINGS OF THE ASME 32ND INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARCTIC ENGINEERING - 2013 - VOL 8, 10.1115/OMAE2013-10618, V008T09A032, 2013.06. |
| 59. | Utsunomiya, T., Yoshida, S., Ookubo, H., Sato, I., Ishida, S., DYNAMIC ANALYSIS OF A FLOATING OFFSHORE WIND TURBINE UNDER EXTREME ENVIRONMENTAL CONDITIONS, PROCEEDINGS OF THE ASME 31ST INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARTIC ENGINEERING, VOL 7, 10.1115/OMAE2012-83985, 559-568, 2012.07. |
| 60. | Kokubun, K., Ishida, S., Nimura, T., Chujo, T., Yoshida, S., Utsunomiya, T., MODEL EXPERIMENT OF A SPAR TYPE OFFSHORE WIND TURBINE IN STORM CONDITION, PROCEEDINGS OF THE ASME 31ST INTERNATIONAL CONFERENCE ON OCEAN, OFFSHORE AND ARTIC ENGINEERING, VOL 7, 10.1115/OMAE2012-83993, 569-575, 2012.06. |
| 61. | K. SHIBANUMA, T. UTSUNOMIYA, Evaluation on reproduction of priori knowledge in XFEM, Finite Elements in Analysis and Design, 10.1016/j.finel.2010.11.007, 47, 4, 424-433, 2011.04. |
| 62. | Tomoaki Utsunomiya, Hidekazu Matsukuma, Shintaro Minoura, Kiyohiko Ko, Hideki Hamamura, Osamu Kobayashi, Iku Sato, Yoshihisa Nomoto, Kentaro Yasui, On sea experiment of a hybrid SPAR for floating offshore wind turbine using 1/10 scale model, ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2010 ASME 2010 29th International Conference on Ocean, Offshore and Arctic Engineering, OMAE2010, 10.1115/OMAE2010-20730, 529-536, 2010.12, This study aims at development of a cost-effective floating offshore wind turbine. The proto-type model considered herein is composed of 1) 2MW horizontal-axis wind turbine (HAWT) of down-wind type, 2) steel mono-tower with 55m hub height above sea level, 3) steel-prestressed concrete (PC) hybrid SPAR-type foundation with 70m draught, and 4) catenary mooring system using anchor chains. In order to demonstrate the feasibility of the concept, on-sea experiment using a 1/10 scale model of the prototype has been made. The demonstrative experiment includes 1) construction of the hybrid SPAR foundation using PC and steel as same as the prototype, 2) drytowing and installation to the on-sea site at 30m distance from the quay of the Sasebo shipbuilding yard, 3) generating electric power using a 1kW HAWT, and 4) removal from the site. During the on-sea experiment, wind speed, wind direction, tidal height, wave height, motion of the SPAR, tension in a mooring chain, and strains in the tower and the SPAR foundation have been measured. Motion of the SPAR has been numerically simulated and compared with the measured values, where basically good agreement is observed.. |
| 63. | C. M. Wang, T. Utsunomiya, S. C. Wee, Y. S. Choo, Research on floating wind turbines A literature survey, IES Journal Part A: Civil and Structural Engineering, 10.1080/19373260.2010.517395, 3, 4, 267-277, 2010.12, This article presents a literature survey of research and development on floating wind turbines. The various, proposed conceptual designs for floating platforms used for floating wind turbines are described and the working principles of these various floater concepts are outlined. This is followed by an overview of the research work that has been undertaken pertaining to floating wind turbine technology by several research institutes and the academic community. The research work undertaken to date is reviewed categorically according to the proposed floater concept (spar-buoy type, TLP type, semi-submersible type, pontoon type and others) as per sections 3-7. Based on the research work undertaken thus far, recommendations for future work are suggested.. |
| 64. | C. M. WANG, Z. Y. TAY, K. TAKAGI, T. UTSUNOMIYA, Literature review of methods for mitigating hydroelastic response of VLFS under wave action, Applied Mechanics Reviews, 10.1115/1.4001690, 63, 3, 030802, 2010.06. |
| 65. | E. P. BANGUN, C. M. WANG, T. UTSUNOMIYA, Hydrodynamic forces on a rolling barge with bilge keels, Applied Ocean Research, 10.1016/j.apor.2009.10.008, 32, 2, 219-232, 2010.04. |
| 66. | Carlos Alberto Riveros, Tomoaki Utsunomiya, Katsuya Maeda, Kazuaki Itoh, Response prediction of long flexible risers subject to forced harmonic vibration, Journal of Marine Science and Technology, 10.1007/s00773-009-0070-5, 15, 1, 44-53, 2010.03, Several research efforts have been directed toward the development of models for response prediction of flexible risers. The main difficulties arise from the fact that the dynamic response of flexible risers involves highly nonlinear behavior and a self-regulated process. This article presents a quasi-steady approach for response prediction of oscillating flexible risers. Amplitude-dependent lift coefficients are considered, as is an increased mean drag coefficient model during synchronization events. Experimental validation of the proposed model was carried out using a 20-m riser model excited by forced harmonic vibration at its top end. Large variations in the hydrodynamic force coefficients, a low mass ratio value, and synchronization events are the main features of the model presented in this article. Experimental validation was provided for the asymmetric, transverse, diagonal, and third vortex regimes.. |
| 67. | K. Shibanuma, H. Aoi, Tomoaki Utsunomiya, M. Sakano, Y. Natsuaki, Development of XFEM analysis code for simulation of fatigue crack propagation in steel structure, 5th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2010 Bridge Maintenance, Safety, Management and Life-Cycle Optimization - Proceedings of the 5th International Conference on Bridge Maintenance, Safety and Management, 2774-2781, 2010, In order to evaluate the behavior of a fatigue crack in the local part of large-scale civil engineering structure, we have implemented a fatigue crack simulation code based on the XFEM approximation into generalpurpose FEM analysis software. Using this simulation code, the behavior of a fatigue crack through thickness of a plate in a three dimensional structure can be quantitatively evaluated. The performance of the developed PU-XFEM code is evaluated through its applications to the numerical simulations of the fatigue crack propagation in the intermediate transverse beam of I-girder bridge and the orthotropic steel deck specimen using bulb rib. It is concluded that the developed PU-XFEM analysis code is useful for the quantitative evaluation on the path and rate of the fatigue crack propagation including the estimation of termination of crack propagation through thickness of a plate in a three dimensional structure.. |
| 68. | K. SHIBANUMA, T. UTSUNOMIYA, Reformulation of XFEM based on PUFEM for solving problem caused by blending elements, Finite Elements in Analysis and Design, 45, 11, 806-816, 2009.09. |
| 69. | Z. Y. TAY, C. M. WANG, T. UTSUNOMIYA, Hydroelastic responses and interactions of floating fuel storage modules placed side-by-side with floating breakwaters, Marine Structures, 22, 3, 633-658, 2009.07. |
| 70. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Dynamic response of oscillating flexible risers under lock-in events, International Journal of Offshore and Polar Engineering, 19, 1, 23-30, 2009.03. |
| 71. | H. MATSUKUMA, T. UTSUNOMIYA, Motion analysis of a floating offshore wind turbine considering rotor-rotation, The IES Journal Part A: Civil and Structural Engineering, 1, 4, 268-279, 2008.10. |
| 72. | D. C. PHAM, C. M. WANG, T. UTSUNOMIYA, Hydroelastic analysis of pontoon-type circular VLFS with an attached submerged plate, Applied Ocean Research, 30, 4, 287-296, 2008.10. |
| 73. | E. P. BANGUN, T. UTSUNOMIYA, Analysis of hydrodynamic forces acting on a rolling body by using Navier-Stokes solver, Journal of Applied Mechanics, JSCE, 11, 1055-1062, 2008.09. |
| 74. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Modeling the response of flexible risers in the quasi-steady regime, Journal of Applied Mechanics, JSCE, 11, 1063-1070, 2008.09. |
| 75. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Damage detection in flexible risers using statistical pattern recognition techniques, International Journal of Offshore and Polar Engineering, 18, 1, 35-42, 2008.03. |
| 76. | C. M. WANG, T. UTSUNOMIYA, H. S. KOH, Heaving response of a large floating platform, The IES Journal Part A: Civil and Structural Engineering, 1, 2, 97-105, 2008.01. |
| 77. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Vibration-based damage detection in flexible risers using time series analysis, Structural Engineering/Earthquake Engineering, 24, 2, 62s-72s, 2007.12. |
| 78. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, CFD modeling of fluid-structure interaction for oscillating flexible risers, Journal of Applied Mechanics, JSCE, 10, 1099-1108, 2007.09. |
| 79. | C. M. WANG, T. UTSUNOMIYA, Research update: Pontoon-type very large floating structures, The Structural Engineer, The international journal of the Institution of Structural Engineers (IStructE), 85, 16, 15-17, 2007.08. |
| 80. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Vibration-based damage detection in flexible risers using time series analysis, Doboku Gakkai Ronbunshuu A, 63, 3, 423-433, 2007.07. |
| 81. | T. UTSUNOMIYA, T. OKAFUJI, Wave response analysis of a VLFS by accelerated Green's function method in infinite water depth, International Journal of Offshore and Polar Engineering, 17, 1, 30-38, 2007.03. |
| 82. | C. M. WANG, W. X. WU, C. SHU, T. UTSUNOMIYA, LSFD method for accurate vibration modes and modal stress-resultants of freely vibrating plates that model VLFS, Computers and Structures, 84, 31-32, 2329-2339, 2006.12. |
| 83. | T. UTSUNOMIYA, E. WATANABE, Fast multipole method for wave diffraction/radiation problems and its applications to VLFS, International Journal of Offshore and Polar Engineering, 16, 4, 253-260, 2006.12. |
| 84. | S. KIDA, T. UTSUNOMIYA, Analysis of the slowly varying drift force on a very large floating structure in multidirectional random seas, Journal of Marine Science and Technology, 11, 4, 229-236, 2006.12. |
| 85. | J.-F. BARIANT, T. UTSUNOMIYA, E. WATANABE, Elasto-plastic analysis of PC girder with corrugated steel web by an efficient beam theory, Structural Engineering/Earthquake Engineering, 23, 2, 257s-268s, 2006.10. |
| 86. | C. RIVEROS, T. UTSUNOMIYA, K. MAEDA, K. ITOH, Numerical scheme for dynamic response of deep-water risers, Journal of Applied Mechanics, JSCE, 9, 1149-1158, 2006.09. |
| 87. | E. WATANABE, T. UTSUNOMIYA, C. M. WANG, L. T. T. HANG, Benchmark hydroelastic responses of a circular VLFS under wave action, Engineering Structures, 28, 3, 423-430, 2006.02. |
| 88. | N. MAKIHATA, T. UTSUNOMIYA, E. WATANABE, Effectiveness of GMRES-DR and OSP-ILUC for wave diffraction analysis of a very large floating structure (VLFS), Engineering Analysis with Boundary Elements, 30, 1, 49-58, 2006.01. |
| 89. | C. MACHIMDAMRONG, E. WATANABE, T. UTSUNOMIYA, Analysis of corrugated steel web girders by an efficient beam bending theory, Doboku Gakkai Ronbunshu, 10.2208/jscej.2004.773_19, I-69, 773, 19-30, 2004.10. |
| 90. | C. M. WANG, Y. XIANG, E. WATANABE, T. UTSUNOMIYA, Mode shapes and stress-resultants of circular Mindlin plates with free edges, Journal of Sound and Vibration, 276, 3-5, 511-525, 2004.09. |
| 91. | K.-L. PARK, E. WATANABE, T. UTSUNOMIYA, Development of 3d elastodynamic infinite elements for soil-structure interaction problems, International Journal of Structural Stability and Dynamics, 4, 3, 423-441, 2004.09. |
| 92. | C. MACHIMDAMRONG, E. WATANABE, T. UTSUNOMIYA, Shear buckling of corrugated plates with edges elastically restrained against rotation, International Journal of Structural Stability and Dynamics, 4, 1, 89-104, 2004.03. |
| 93. | E. WATANABE, T. UTSUNOMIYA, C. M. WANG, Hydroelastic analysis of pontoon-type VLFS: a literature survey, Engineering Structures, 26, 2, 245-256, 2004.01. |
| 94. | E. WATANABE, T. UTSUNOMIYA, M. KURAMOTO, H. OHTA, T. TORII, N. HAYASHI, Wave response analysis of VLFS with an attached submerged plate, International Journal of Offshore and Polar Engineering, 13, 2, 190-197, 2003.09. |
| 95. | E. WATANABE, T. UTSUNOMIYA, Analysis and design of floating bridges, Progress in Structural Engineering and Materials, 5, 3, 127-144, 2003.09. |
| 96. | C. MACHIMDAMRONG, E. WATANABE, T. UTSUNOMIYA, An extended elastic shear deformable beam theory and its application to corrugated steel web girder, Journal of Structural Engineering, JSCE, 49A, 1, 29-38, 2003.04. |
| 97. | E. WATANABE, T. UTSUNOMIYA, N. YOSHIZAWA, Dynamic wave response analysis of floating bodies in the time-domain, Computational Structural Engineering, 2, 1, 43-50, 2003.01. |
| 98. | C. MACHIMDAMRONG, E. WATANABE, T. UTSUNOMIYA, Global elastic shear buckling analysis of corrugated plates with edges elastically restrained against rotation, Journal of Structural Engineering, JSCE, 48A, 1, 51-58, 2002.04. |
| 99. | Y. XIANG, C. M. WANG, T. UTSUNOMIYA, C. MACHIMDAMRONG, Benchmark modal stress-resultant distributions for vibrating rectangular plates with two opposite edges free, Computational Structural Engineering, 1, 1, 49-57, 2002.01. |
| 100. | C. M. WANG, Y. XIANG, T. UTSUNOMIYA, E. WATANABE, Evaluation of modal stress resultants in freely vibrating plates, International Journal of Solids and Structures, 38, 36-37, 6525-6558, 2001.09. |
| 101. | T. UTSUNOMIYA, R. EATOCK TAYLOR, Resonances in wave diffraction/radiation for arrays of elastically connected cylinders, Journal of Fluids and Structures, 14, 7, 1035-1051, 2000.10. |
| 102. | C. M. WANG, T. UTSUNOMIYA, E. WATANABE, On obtaining accurate stress resultants in vibration analysis of floating plate structures, Journal of the Institution of Engineers, Singapore, 40, 5, 31-42, 2000.09. |
| 103. | E. WATANABE, T. UTSUNOMIYA, A. KUBOTA, Analysis of wave-drift damping of a VLFS with shallow draft, Marine Structures, 13, 4-5, 383-397, 2000.07. |
| 104. | T. UTSUNOMIYA, R. EATOCK TAYLOR, Trapped modes around a row of circular cylinders in a channel, Journal of Fluid Mechanics, 386, 259-279, 1999.05. |
| 105. | E. WATANABE, T. UTSUNOMIYA, S. TANIGAKI, A transient response analysis of a very large floating structure by finite element method, Doboku Gakkai Ronbunshu, 10.2208/jscej.1998.598_1, I-44, 598, 1-9, 1998.07. |
| 106. | C. WU, T. UTSUNOMIYA, E. WATANABE, Harmonic wave response analysis of elastic floating plates by modal superposition method, Doboku Gakkai Ronbunshu, 10.2208/jscej.1997.556_43, I-38, 556, 43-52, 1997.01, [URL]. |
| 107. | C. WU, E. WATANABE, T. UTSUNOMIYA, An eigenfunction expansion-matching method for analyzing the wave-induced responses of an elastic floating plate, Applied Ocean Research, 17, 5, 301-310, 1995.10. |
| 108. | T. UTSUNOMIYA, H. NISHIZAWA, K. KANETA, Biaxial stress measurement using a magnetic probe based on the law of approach to saturation magnetization, NDT&E International, 24, 2, 91-94, 1991.04. |
| 109. | T. UTSUNOMIYA, H. NISHIZAWA, K. KANETA, Effect of stress on the law of approach to saturation magnetization in carbon steels, IEEE Transactions on Magnetics, 27, 3, 3420-3425, 1991.05. |
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