竖向及水平荷载下预应力框架调幅的模拟分析

Analysis of Moment Modulation with Simulated Concrete Frame under Vertical and Horizontal Load

根据曲率力法编制的非线性程序,模拟了十八榀单层单跨有粘结预应力混凝土框架,通过改变框架梁截面相对受压区高度、次弯矩以及加载方式等因素,初步阐明了影响有粘结预应力混凝土框架内力重分布和弯矩调幅的因素及规律。总弯矩调幅系数随着相对受压区高度ξ的增大而减小;同时当ξ较大时,次弯矩将有助于调幅能力的提高。有粘结预应力混凝土框架既承受水平荷载又承受竖向荷载时,在破坏端的总弯矩调幅系数比相同结构只承受竖向荷载的总弯矩调幅系数要大,竖向承载力则可能减小。

In this paper, by means of the nonlinear analysis program on basis of the curvature-force method, 18 one-story and one-span bonded pre-stressed concrete frames are simulated. Among the frames, the factors, including the relative height of compressive zone of section, secondary moment and types of load application are taken into account. Then, some conclusions are achieved about the redistribution of internal force and the modulation of moment for bonded pre-stressed concrete frames. The total coefficient of modulation of moment is reduced with increase of the height of compressive zone of the section (ξ). The effect of secondary moment on redistribution of moment is enhanced with larger ξ.The total coefficient of modulation of moment in the failure section for the bonded pre-stressed concrete frame under horizontal load and vertical load is larger and the ultimate vertical load may be less than that of the same frame applying vertical load.