非线性阶段预应力次弯矩概念及其在弯矩调幅中的应用

发布时间：2019-04-17 08:17

【摘要】：非线性阶段次弯矩的演化,以及承载力极限状态下是否考虑次弯矩的问题一直存在争议。为解决这一问题,拓展了预应力次弯矩的概念,使其能够适用于非线性阶段。运用变刚度法数值模拟了初始次弯矩(M2)与弹性最大荷载弯矩(Me)之比为0.15~0.36的15根有黏结预应力混凝土两跨连续梁。基于拓展后的次弯矩概念,提出了以混凝土受压区相对高度、初始次弯矩与弹性最大荷载弯矩之比为影响参数的有黏结预应力混凝土连续梁弯矩调幅公式。采用已有文献中受压区相对高度为0.35的试验梁比较了所提公式和现有的弯矩调幅公式。设计制作受压区相对高度为0.18的两跨预应力混凝土连续梁,获取单调加载下支座反力数据,检验了内力重分布程度较大时所提公式的效果。结果表明,给出的弯矩调幅公式的计算结果偏于安全,且更接近试验结果。
[Abstract]:The evolution of nonlinear secondary bending moment and the question of whether the secondary bending moment is considered under the limit state of bearing capacity have been controversial. In order to solve this problem, the concept of prestressing secondary bending moment is extended so that it can be applied to the nonlinear stage. The variable stiffness method is used to simulate 15 bonded prestressed concrete two-span continuous beams with the ratio of initial secondary bending moment (M2) to elastic maximum load bending moment (Me) of 0.15 脳 0.36. Based on the extended concept of secondary bending moment, a moment modulation formula of bonded prestressed concrete continuous beam is proposed, which is based on the relative height of concrete compression zone and the ratio of initial secondary bending moment to elastic maximum bending moment. The proposed formula and the existing bending moment amplitude modulation formula are compared with the experimental beam with the relative height of the compression zone of 0.35 in the literature. A two-span prestressed concrete continuous beam with a relative height of 0.18 is designed and fabricated. The data of support reaction under monotonic loading is obtained and the effect of the proposed formula is tested when the internal force is redistributed. The results show that the calculated results of bending moment amplitude modulation formula are more safe and closer to the experimental results.
【作者单位】：同济大学建筑工程系;深圳市建筑设计研究总院有限公司;
【基金】：国家自然科学基金项目(51178328) 高等学校博士学科点专项科研基金项目(20100072110053)
【分类号】：TU378

【共引文献】