researchondeflectionofstrengtheningconcretebeamwithprestressedcfrpsheets-外文文献(编辑修改稿)

researchondeflectionofstrengtheningconcretebeamwithprestressedcfrpsheets-外文文献(编辑修改稿)内容摘要：

ngthening of CFRP sheets； crI — converted second moment of cracking section after the strengthening of CFRP sheets； . Displacement generated by the prestressed steel Under the prestress of steel strands, the moment of inertia of prestressed concrete members should adopt that of the pretension stage. The displacement is calculated according to the following formula: ∫= dsIEMMncpexpeδ （ 4） In which， peM — bending moment caused by existing pretension of steel strands at any section x； nI — moment of inertia of the members at the stage of longitudinal steel strands pretension； . Displacement generated by prestressed CFRP sheets Under CFRP sheets prestress, the moment of inertia of prestressed concrete members should take the converted second moment of area at the strengthening stage. The displacement is calculated according to the following formula: ∫= dsBMMcrcfexcfeδ （ 5） In which， cfeM —— bending moment caused by CFRP sheets existing pretension at any section x； 3. Analysis of rigidity Rigidity 0B andcrB are decided by 0I andcrI . The paper is to derive the calculation method of prestressed CFRP strengthening concrete box girders’ section 0I and crI under the premise that the depth of the tensile area is covered by the web (as shown in ). According to Reference [5], the members work with cracks. At the tensile area the concrete fails and transforms the tension on it to the longitudinal reinforcement which at this stage does not yield and the pressive stress of the concrete takes the shape of triangle. With the CFRP sheets, the sectional area of the steel bar and CFRP sheets should be converted into the concrete sectional area wh。