一、前言预应力混凝土受弯构件设计,主要包括选择截面尺寸,确定预应力的大小和位置,以保证构件上任一点在任何阶段的应力均处于允许范围之内。但传递预应力阶段和全部使用荷载阶段的允许拉压应力不同。 十几年来,人们提出了多种预应力混凝土 Preface Prestressed concrete flexural members design, including the choice of cross-sectional size, determine the size and location of prestress, to ensure that any point in the component at any stage of the stress are within the allowable range. However, the allowable tensile and compressive stresses are different between the pre-stressed stage and the full used load stage. For more than a decade, many types of prestressed concrete have been proposed