预弯复合梁开裂后的正截面强度

Strength of Cross Section after Preflexed Composite Beam Cracks

本文根据跨度为4.0m的预弯复合梁在一次性加载破坏过程中实测的梁挠度、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、截面几何形心随作用荷载的移动规律,从而提出了预弯复合梁一次性加载破坏过程中,一期混凝土开裂状态时的刚度和强度实用计算式。

Based on the relation between the deflection, the strain and the applied load measured during oneshot loading on a preflexed composite beam with the span of 4.0m , rules of the rigidity attenuation and the movement of sectional center of gravity of the beam after its cracking with applied load are obtained. Therefore, the practical formulas of rigidity and strength of the first-stage concrete in the process of one -shot loading on the preflexed composite beam are presented.