報告書番号

384027

タイトル（和文）

鉄筋コンクリートスラブの衝撃応答特性および有限要素法による解析

タイトル（英文）

IMPACT BEHAVIOR OF REINFORCED CONCRETE SLABSSUBJECTED TO HARD PROJECTICAL AND ITS ANALYSIS BY FEM

概要 （図表や脚注は「報告書全文」に掲載しております）

我国の原子力発電所格納施設は，地震荷重や仮想事故時の圧力，温度上昇などの荷重条件を考慮して設計が行われている。本研究はそのような荷重条件下で設計された鉄筋コンクリート製構造物が保有している衝撃荷重に対する余裕度の検証を目的として実施している。本報告は，鉄筋コンクリート構造物の基本的な構成要素である鉄筋コンクリートスラブによる衝撃実験を行い，衝撃応答特性を実験的に明らかにするとともに，飛来物の貫入深さ，裏面剥離限界および貫通限界の算定式を提案した。さらに，有限要素法による衝撃応答解析法は，鉄筋コンクリートスラブの衝撃現象を解析するのに著しく有効であることを明らかにした。

概要 （英文）

THIS PAPER PRESENTS A METHOD THAT CAN BE USED TO EVALUATE THE OVERALL DYNAMIC RESPONSE AND LOCAL BEHAVIOR OF REINFORCED CONCRETE STRUCTURES SUCH AS THE CONCRETE CONTAINMENT VESSEL IN THEEVENT OF IMPACT LOADING DUE TO HARD PROJECTILES. A SUMMARY OF THE RESULTS IS SHOWN BELOW. (1)THE RC SLABS STRUCK BY THE HARD PROJECTILE ARE DAMAGED BY THE PUNCHING SHEAR. THE MAXIMUM IMPACT FORCE IS CONSIDERABLY LARGER THAN THE STATIC ULTIMATE CAPACITY OF THE PUNCHING SHEAR. (2)THE PENETRATION DEPTH OF RC SLABS IS PROPORTIONAL TO A SQUARE OF IMPACT VELOCITY.IN OTHER WORDS,PENETRATION DEPTH DEPENDS UPON KINETIC ENERGY.MOREOVER,THE MODIFIED NDEC FORMULA WHICH IS WIDELY USED TO CALCULATE PENETRATION DEPTH GIVES REMARKABLY CONSERVATIVE VALUES THAN THAT OBTAINED FROM EXPERIMENTAL RESULTS.ACCORDINGLY,AN EMPIRICAL FORMULA WHICH IS ABLE TO GET MORE EXACT VALUE CONSIDERING THE INFLUENCE OF CONCRETE STRENGTH AND THE THICKNESS OF SLAB WAS DERIVED FROM TEST DATA. (3)REINFORCED CONCRETE STRUCTURES MUST BE SUFFICIENTLY THICK IN ORDER TO PREVENT AGAINST THE DAMAGE OF THE REAR FACE SCABBING OR COMPLETE PERFORATION DUE TO IMPACT LOAD.EMPIRICAL FORMULAE FOR NONDEFORMABLE SOLID CYLINDRICAL PROJECTILE WERE SUGGESTED. (4)AS FOR THE STRAIN OF REINFORCING BARN THE LOWER PORTION OF THE SLABS,A CHARACTERISTICS IN RESPONSE ARE THAT COMPRESSIVESTRAIN IMMEDIATELY AFTER IMPACT IS GENERATED.THIS PHENOMENON CAN BE EXPLAINED BY THE AID OF PROPAGATION OF STRESS WAVES. (5)IT IS MADE CLEAR THAT THE TRANSIENT STRAIN-TIME HISTORIES CALCULATED BY THE FEM-PROGRAM ARE RELATIVELY IN GOOD AGREEMENT WITH EXPERIMENTAL RESULTS.THE CHARACTERISTICS OF CONCRETE AND REBAR IN THE ANALYSIS ARE NONLINEAR STRESS-STRAIN RELATION,STRAIN HARDENING UNDER MULTIAXIAL STRESS CONDITION,AND STRAIN RATE EFFECT.

報告者

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