Finite element analysis of prestressed concrete beams considering realistic cable profile

Cable profile plays a very important role in the stress analysis of prestressed concrete (PC) structures. Cable thrust on concrete is related to its curvature. Actual cable profile is a smooth curve which may have varying curvature along the span. To simplify the analysis, cable profile is generally modeled by parabola as it produces constant curvature. But profile, thus modeled, becomes discontinuous at supports. If cable profile, to maintain continuity, is modeled by higher order polynomial, it results in a very zigzag shape. In order to overcome these difficulties, in this study, cable profile is modeled by B-spline. Two dimensional finite element analysis of PC beams is carried out and results are compared with those obtained by other reported models. It is found that there is considerable variation in stresses. Hence for accurate design, realistic cable profile should be accounted.