Papers - HIBINO, Yo

EFFECTS OF COLUMN-TO-BEAM STRENGTH RATIO ON SEISMIC ENERGY DISTRIBUTION IN STEEL FRAME STRUCTURES Reviewed

Yo HIBINO and Toshikatsu ICHINOSE

Journal of Structural Engineering   Vol. 51B   page： 277-284   2005.3

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Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)  

This paper presents a numerical study on the column-to-beam strength ratio that affects the seismic energy dissipation of beams and columns in fish-bone-type steel moment frames. The major parameters are number of stories, strengths of columns and beams, and ground motions. The seismic energy dissipation is classified into two categories: energies contributing to story mechanism and total mechanism. The following conclusions are obtained: (1) It is suitable for the column-to-beam strength ratio to be defined by the total of the strength of the beams and columns at a node for evaluating the seismic response; (2) As the column-to-beam strength ratio increases from 1 to 1.3, the energies contributing to story mechanism decreases significantly in the most cases.

New Method for Estimating Seismic Response of Frame Structures Considering Collapse Mechanism Reviewed

Yo HIBINO, Hisashi UMEMURA, Toshikatsu ICHINOSE

Proceedings of the 13th World Conference on Earthquake Engineering     page： 2357   2004.8

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)  

For seismic performance-based design, it is important to evaluate structural performance for various seismic excitations. The absorbed energy in a structure, which is closely related to the seismic damages, can be an index to evaluate a building by performance. The energy attributed to the total and collapse mechanisms were evaluated for RC and steel frame structures under 84 ground motions and were
compared each other to study energy demand on structure. The maximum drifts gained by dynamic response analyses were compared with the cumulative plastic story drifts evaluated from energy. Then, a factor which indicates the relationships between cumulative plastic story drifts and dynamic responses were obtained. The estimation method was presented using the factor and its applicability was evaluated.

EVALUATION OF SEISMIC RESPONSE FOR BUILDINGS USING STORY-SHEAR-SAFETY FACTOR BASED ON ENERGY PRINCIPLE Reviewed

Yo Hibino, Nanako Marubashi, Hisashi Umemura, Toshikatsu Ichinose

Proceedings of the ninth East Asia-pacific conference on Structural Engineering and Construction     page： VID-97-VID-102   2003.12

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Authorship：Lead author   Language：English   Publishing type：Research paper (international conference proceedings)  

It is important to estimate the response of buildings under earthquakes from the viewpoint of life reservation and risk management. This paper presents a method to estimate the story drifts of both RC and steel buildings using a story-safety factor (SSF) based on the energy concept. In this paper, the method was verified by dynamic response analyses of RC and steel structures with various conditions. The method predicted the mean of story drifts well irrespective of the differences in the models used.

PROBABILISTIC ESTIMATION OF SEISMIC RESPONSE OF BUILDINGS CONSIDERING UNCERTAINTY OF COLLAPSE MODE Reviewed

Nanako Marubashi, Yo Hibino, Hisashi Umemura, Toshikatsu Ichinose

Proceedings of the ninth East Asia-pacific conference on Structural Engineering and Construction     page： MCS-1-MCS-6   2003.12

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Language：English   Publishing type：Research paper (international conference proceedings)  

This paper estimates the effect of strength deterioration on the seismic response of reinforced concrete (RC) structures with a weak story. Strength deteriorates because of partial failure or the P-delta effect. In particular structures with weak stories tend to collapse accompanied by strength deterioration. The story with strength deterioration cannot consume much cumulative plastic energy, thus exhibiting large-scale deformations. We predicted the capacity of the cumulative plastic energy of the story through the number of reversed cycles of shear force. The numbers of reversed cycles are related to the duration of the input ground motions. Therefore, we selected ground motions with various durations while the coefficient of strength degradation is selected as a structural parameter. And we examined the seismic response of structures with a weak story. The structures are designed using the "story-shear-safety factor" which represents the capacity against story collapse. As a result, the relation between the duration and the reversed cycle was formulated. We then proposed an effective method to predict the capacity of cumulative plastic energy by using the formula.

DEVELOPMENT OF EDUCATIONAL SOFTWARE FOR STRUCTURAL MECHANICS Reviewed

Naoya WAKITA, Yo HIBINO, Tomoharu HAYASE, Toshikatsu ICHINOSE

Journal of Architecture and Building Science   ( 17 ) page： 525-530   2003.6

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Language：Japanese   Publishing type：Research paper (scientific journal)  

Computer software for structural mechanics was developed to improve education of structural mechanics. A new lecture style was proposed using this software and accompanying manuals. This software visualizes mechanics including bending moment, axial or shear force and so on. Each student can easily understand these concepts through virtual experiment on computer changing the location or the magnitude of force as if he or she was loading forces on a real structure. Results of questionnaire proved that this software is effective for studying structural mechanics.