预应力筋线型及预应力内荷载的分布规律

针对二次抛物线不能准确反映预应力筋实际线型特点的事实,提出了采用三次样条插值函数作为预应力筋的布筋线型函数,并在理论上确定了预应力筋反弯点的空间几何位置·根据预应力内荷载的特点,推导了预应力内荷载的计算方法,并应用这种函数精确地确定了预应力内荷载的分布规律·同时,设计了单层单跨预应力钢筋混凝土框架结构,对试件进行了实测,并结合大型ANSYS有限元分析程序进行数值模拟研究·试验结果和ANSYS有限元数值模拟结果相互吻合,验证了预应力筋的线型为三次样条插值曲线及预应力内荷载的分布规律为曲线函数的结论·

Behavior of Tendon Profile and Distribution of Prestressed Internal Load

A cubical spline interpolation function is put forward to show the tendon profile of prestressed bars because the tendon profile can't be accurately expressed by the quadric parabola. With the cubical spline, the spatial location of tendon's inflexion and the way to calculate prestressed internal load are both given theoretically and the nonlinear distribution of prestressed internal load is revealed. In addition, two samples of prestressed RC frames of single floor and span are tested with a numerical simulation done by ANSYS. The results of experiments and numerical simulation are very near. Thus, a conclusion is drawn that the tendon profile shows a cubical spline interpolation curve and that the prestressed internal load is distributed nonlinearly.