预弯复合梁在反复荷载作用下正截面强度的试验研究

• 作 者: 竺存宏
• 机 构: 交通部天津水运工程科学研究所
• 出 处: 建筑结构学报
• 发表日期: 1995年01期
• 关键词: 复合梁 反复荷载作用 预弯 正截面 梁的挠度 足尺试验 截面惯性矩 砼梁 试验梁 跨中挠度

本文根据跨度为１２．０ｍ的预弯复合梁（即预应力劲性砼梁）足尺试验结果，观察梁在反复荷载作用下裂缝发生、发展及闭合规律，测定梁的挠度、截面应变与作用荷载的关系，得出了预弯复合梁开裂后刚度随作用荷载的衰减规律，有效截面的几何形心随作用荷载的移动规律，从而得出预弯复合梁开裂后刚度及强度的实用计算式。它与国外现行规范相比，物理概念明确，计算结果更接近梁开裂后的实际工作状态。

In this paper, according to the full-scale test results of a pre-bent composite beam with a span of 12.0 m, the occurrence, development and closure of cracks under repeated loadings are observed, and the deflection, cross-section strain and effect of the beam are measured. Based on the relationship between loads, the law of attenuation of pre-bent composite beams after cracking is obtained, and the law of movement of geometric centroids of effective cross-sections with applied loads is derived. Thus, a practical formula for the post-cracking stiffness and strength of pre-bent composite beams is obtained. . Compared with the current foreign norms, the physical concept is clear and the calculation results are closer to the actual working state after the cracking of the beam.