MORITA Chihiro

写真a

Title

Professor

Field of expertise (Grants-in-aid for Scientific Research classification) 【 display / non-display

  • Structural engineering/Earthquake engineering/Maintenance management engineering

 

Papers 【 display / non-display

  • A HBM approach for temperature and heat flux convection–diffusion equations and nonlinear problems

    Zhao Y., Huang M., Tang J., Ouyang X., Morita C.

    Nuclear Engineering and Design   342   115 - 127   2019.02  [Refereed]

    Joint Work

     View Summary

    © 2018 Elsevier B.V. Solving convection diffusion equation is widely required in many fields of science, technology and engineering. The calculation is usually difficult and time-consuming. In this paper, a highly efficient method, the half boundary method (HBM), is proposed to solve the convection diffusion equation. The main idea of HBM is to reduce the order of the convection–diffusion equations by introducing a new variable and constructing the relations of the variables between the nodes inside the area and the nodes on half of the boundaries. Using the relations, the temperature and heat flux at any point can be calculated simultaneously, after obtaining the variables on the half of the boundaries. Because the unknown variables exist on only half of the boundaries, the computing matrix is reduced to only second order regardless of the number of nodes, the internal storage in the HBM is even less than that required in the finite volume method, making the HBM extremely fast and efficient. The validity and accuracy of the proposed method are investigated. Numerical studies for steady and unsteady, as well as nonlinear convection–diffusion equations, were carried out. The results show that HBM is more accurate than the finite volume method under identical grids conditions.

    DOI

  • ESTBLISHMENT OF MICHIMORI TRAINING COUSE FOR DEVELOP INFRASTRUCTURE MAINTENANCE ENGINEERS AND EFFORTS TO UTILIZE MICHIMORI CERIFIED PERSONS

    MATSUDA Hiroshi, NAKAMURA Shozo, MORITA Chihiro, OKUMATSU Toshihiro, TAKAHASHI Kazuo

    Journal of Japan Society of Civil Engineers, Ser. F4 (Construction and Management)   73   I_21 - I_32   2017.12  [Refereed]

    Joint Work

     View Summary

    &nbsp;Nagasaki University Infrastructures Lifetime-Extending Maintenance Research Center is striving to train infrastructure maintenance engineers. In 2008, Nagasaki University opened a MICHIMORI training course to nurture experts in the maintenance and management of roads ahead of the rest of the country.<br>&nbsp;We have developed a curriculum for MICHIMORI training courses for infrastructure maintenance and management for civil engineers and have continued human resource development. Until now, the activities of MICHIMORI certified people were mainly volunteers. In 2015, MICHIMORI training course was approved by the Ministry of Land, Infrastructure and Transport. It was recognized as qualification for infrastructure maintenance. In addition, the range of activities expanded.<br>&nbsp;In this paper, we summarized the implementation system of MICHIMORI training course, curriculum, achievement evaluation standards, number of trainees etc. In addition, we report the future policy of MICHIMORI certified persons.

    DOI CiNii

  • QUESTIONNAIRE SURVEY ON ACTIVITIES AND INTENTIONS OF MICHIMORI CERTIFIED PERSONS AND REFLECTION TO THE MICHIMORI TRAING UNIT

    TAKAHASHI Kazuo, MATSUDA Hiroshi, NAKAMURA Shozo, MORITA Chihiro

    Journal of Japan Society of Civil Engineers, Ser. F4 (Construction and Management)   73   I_10 - I_20   2017.12  [Refereed]

    Joint Work

     View Summary

    &nbsp;In 2008, Nagasaki University opened a MICHIMORI training course to nurture experts in the maintenance and management of roads ahead of the rest of the country. It is a collaborative consortium of construction industry, the university and local government. We develop human resources necessary for infrastructure maintenance management.<br>&nbsp;In April 2015, the number of MICHIMORI certified people reached approximately 200. The activities, uses and intentions of MICHIMORI certified persons have not been specifically articulated so far. Based on this questionnaire survey, we gained understanding of the current status of activities as a MICHIMORI certified person, activities as a specialized engineer, obtaining information on MICHIMORI, self-evaluation as a MICHIMORI certified person.<br>&nbsp;We surveyed the situation of the MICHIMORI training course and clarified the issues. Also, based on the results of the questionnaire survey, we will review our future MICHIMORI training course.

    DOI CiNii

  • OPTICAL FULL-FIELD INSPECTION METHOD OF STEEL FATIGUE CRACKING DUE TO THERMAL LOAD WITHOUT REMOVING COATING FILM

    MATSUDA Hiroshi, KOGANEMARU Satoshi, KUSANO Kazutoshi, ITO Yukihiro, MORITA Chihiro

    Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))   72   I_643 - I_652   2017.01  [Refereed]

    Joint Work

     View Summary

    In recent years, the occurrence case of fatigue crack has been an increase steel piers and steel deck, etc. in the road bridge. Depending on the site of the fatigue crack occurs, the crack is progress, cause brittle fracture. As a result, fatigue cracks will be a significant impact on the safety of the bridge. Therefore, finding them early, it is important to perform appropriate repair. This study is intended to develop a measurement method for detecting fatigue cracks. In this measurement method, first, by heating the steel members to open and close the cracks, and distortion difference before and after heating is measured using a digital image correlation method. This measurement method is a new detection method of crack defects of the steel member that does not require removal of the coating.

    DOI CiNii

  • Free vibration analysis of stepped rectangular plates resting on non-homogeneous elastic foundations

    Huang M., Sakiyama T., Matsuda H., Morita C.

    Engineering Analysis with Boundary Elements   50   180 - 187   2015.01  [Refereed]

    Joint Work

     View Summary

    © 2014 Elsevier Ltd. A Half Boundary Method (HBM) is proposed for analyzing the free vibration problem of rectangular plates with stepped thickness resting on non-homogeneous elastic foundations. The unknown quantities of the method exist only on half of the boundary. The non-homogeneous elastic foundation discussed here consists of two-segment elastic Winkler foundation. The fundamental differential equations are established for the bending problem of the plate on elastic foundations. The Green function, which is obtained by transforming these differential equations into integral equations and using numerical integration, is used to establish the characteristic equation of the free vibration. The effects of the modulus of the foundation, the stepped thickness and aspect ratio on the frequency parameters are considered. By comparing the present numerical results with those previously published, the efficiency and accuracy of the present method are investigated.

    DOI

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Presentations 【 display / non-display

  • Human resource development of bridge inspection engineers in Miyazaki

    Chihiro MORITA  [Invited]

    International Symposium on Infrastructure Maintenance and Management in Asia  2019.03  -  2019.03