This paper presents the stress distribution of the damaged butt joint of steel plate using CFRP laminates when the flange in tension zone of steel box girder is welded by butt welding. When CFRP sheets are patched on tension flange of steel-box girder, the stress distribution of a vertical and normal direction on damaged welding part is shown as parameters such as a variation of the thickness of adhesive, the overlap length with steel, and the modulus of elasticity of CFRP sheets. For the study, we wrote the computer program using the EAS(Enhanced assumed strain) finite element method for plane strain that has a very fast convergency and exact stress for distorted shape.

ABSTRACT
 1. 서 론
 2. EAS 유한요소법
  2.1 변분법
  2.2 변형률-변위 관계
  2.3 응력-변형률 관계
  2.4 요소강성
  2.5 응력회복(Stress Recovery)
 3. 해석 예 및 결과분석
  3.1 해석모델
  3.2 예비해석 및 해석 매개변수 선정
  3.3 강재와의 접착길이의 영향
  3.4 접착제의 두께( t a )의 영향
  3.5 CFRP 강도 변화의 영향
 4. 결 론
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