用弯矩曲率法分析预应力钢-混凝土组合梁的钢索受力状态

由于体外预应力组合梁在受力过程中预应力钢束的长度发生较大幅度的变化,所以必须考虑预应力钢束在受力过程中应力的变化。作者提出的弯矩曲率法能够较好地模拟预应力组合梁的受力过程,能以较少的计算工作量有效地计算梁在极限状态的应力及变形,准确地计算出预应力钢束的应力变化。与用有限元进行分析计算相比可知:用有限元计算时,在进入塑性阶段以后,每级荷载的计算时间大约为 1 h,并且计算有可能不收敛;而采用弯距曲率法计算大约只需3 min左右(极限荷载的计算大约需要20 min),且没有不收敛的现象发生。

Analysis of Prestressed Composite Steel-Concrete Beams by Moment Curvature Method

The length of prestressed tightwire changes markly when external prestressed composite steel-concrete beams are subjected to the force, so the change of the stress in external prestressed tightwire must be considered. The moment curvature method was presented to simulate the loading process of the composite steel-concrete beam. By using the method, it effectively calculate the stress and deformation of the beam at the ultimate state with less calculation effort and accurately get the stress changes in the prestressed tightwire. Using finite element method, the calculating time for each grade loading is about 1h, and the results may be not convergent, but using proposed moment curvature method, it only spend 3 min and without the occurrence of non-convergent phenomenon.