報告書番号

U92061

タイトル（和文）

有限要素法による免震用積層ゴムの大ひずみ解析法の開発

タイトル（英文）

FINITE ELEMENT METHOD FOR LARGE STRAIN ANALYSIS OF LAMINATED ELASTOMER BEARING FOR SEISMIC ISOLATION

概要 （図表や脚注は「報告書全文」に掲載しております）

積層ゴムの終局時の力学特性評価を目的に混合法を用いた３次元ＦＥＭ解析プログラムの開発を行った。本解析プログラムは２７節点のアイソパラメトリック要素を採用し，比較的少ない要素数で高精度の計算結果が得る事が可能である。また，ゴムの圧縮性も考慮でき，要素のゆがみが大きくなった場合に有効なリメッシュ機能を有している。１要素を大変形させた際の計算結果は理論解と非常に良く一致し，積層ゴムの軸方向載荷時の挙動を解析した結果は既存の汎用コード（ＡＢＡＱＵＡＳ）等に比べ実験結果と良い一致を見た。せん断試験結果に対してはせん断ひずみで４００％を越える大変形まで追従可能な事が確認された。

概要 （英文）

A COMPUTER CODE BASED ON THE MIXED FINITE ELEMENT METHOD WAS DEVELOPED FOR THREE-DIMENSIONAL LARGE-STRAIN ANALYSES OF LAMINATED ELASTOMERS INCLUDING NONLINEAR BULK STRESS VS. BULK STRAINRELATIONSHIPS,AND REMESHING FOR EXCESSIVE DISTORTION. THE VARIABLE NODE ELEMENT WAS USED WITH 27 MAXIMUM NODE NUMBERS FOR DISPLACEMENT AND FOUR PRESSURE. FIRST,THE DISPLACEMENTS AND PRESSURES WERE CALCULATED USING SINGLE ELEMENTS UNDER VARIOUS LOAD CONDITIONS. THE RESULTS WERE COMPARED WITH RIGOROUS SOLUTIONS AND AGREEMENTS FOR UP TO 6 DIGITS WERE OBTAINED. NEXT,LAMINATED ELASTOMERS SUBJECTED TO AXIAL LOADINGS WERE ANALYZED USING BOTH THE PRESENT CODE AND THE ABAQUS CODE;THE RESULTS WERE COMPARED WITH THE EXPERIMENTAL RESULTS. THE AGREEMENT OF THE PRESENT CODE WITH THE EXPERIMENTED RESULTS WAS BETTER THAN THAT OF THE ABAQUS CODE MAINLY DUE TO THE ABILITY TO HANDLE A WIDER RANGE OF MATERIAL PROPERTIES. LASTLY,SHEARING TESTS OF LAMINATED ELASTOMERS WERE SIMULATED. THE RESULTS WERE IN GOOD AGREEMENT WITH THE EXPERIMENTAL ONES FOR UP TO 400% SHEAR STRAIN.

報告者

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