| Project/Area Number |
07650670
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Nihon University |
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Principal Investigator |
TOSAKA Nobuyoshi Nihon University, Professor, 生産工学部, 教授 (00059776)
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| Project Period (FY) |
1995 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | Inverse Problem / Finite Element / Boundary Element / Filter Theory / Defect Identification / Damage Detection / Elastic Body / 弾性体 / カルマンフィルタ / 射影フィルタ / 構造損傷同定 / 非定常熱伝導 / 内在欠陥 / 円形欠陥 / 弾性定数 |
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| Research Abstract |
1.Novel Solution Procedure for Inverse Problems
From view-point of computational mechanics, noval solution procedures to solve various inverse problems in structure are proposed. These procedures are a combination of the finite element method or the boundary element method to solve numerically continuous fild and the filtering algorithms based on the Wiener filter or the projection filter to estimate the unknown state vector.
Especially, for complicated inverse problems, two step solution procedure to be expected more efficiency is also proposed. The first step analysis is performed to guess some apriori information on the unknowns and the second analysis to identify the unknowns is subsequently performed with use of the obtained apriori information.
2.Application to Various Inverse Probelms
Applicability and effectiveness of the procedures are demonstrated with numerical simulations on the following problems.
(1)Indetification of Spatial Distribution of Material Constants
The solution procedure can be applied to identification analysis of spatial distribution of elastic constants (Young's modulus and Poisson's ratio) in elastic body with use of displacement components measured on the boundary.
(2)Defect(s) Identification
The procedure can be applied to identification of unknown defect in elastic field or in thermal field. Especially, numerical simulation is carried out for identification of a circular defect in a two dimensional body by using transient temparature measured at several boundary points as additional information. The unknown plural defects in elastic body can be identification from the measured displacement components by using effectively two step solution procedure.
(3)Damage Detection
The procedure is applied to a structural damage detection problems. Both location and stiffness on damage in the unit-linked floating structure can be defected with natural frequencies of structure.
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