粘钢加固预应力混凝土梁抗弯承载力及变形的简化计算方法

在模型试验和有限元分析的基础上,首先分析了粘贴钢板厚度和梁侧粘钢高度、有效预应力大小、初始损伤程度等参数对预应力混凝土梁粘钢抗弯性能的影响.在基本假设基础上,分别推导了U型粘钢加固预应力混凝土梁的抗弯极限承载力和变形的简化计算公式.结果表明:梁侧面粘贴钢板高度不超过梁高的1/3比较适宜,有效预应力和初始损伤不会改变明显其极限承载力,建立的简化公式计算结果与实测结果及有限元分析结果吻合较好.

Simplified calculation methods of flexural load-carrying capacity and deformation of prestressed concrete beams strengthened with U-shape steel plates

Based the experimental study and nonlinear analysis, the parameter numerical analysis were conducted to investigate the flexural performances of the prestressed reinfroced concrete (PRC) beams strengthened with U-shaped steel plates. The parameters, such as thickness of steel plate, heigth of the sided- plate, initial damage degree, and different level of effective prestressing were taken account to analyze their effect on the flexural strengthening. Based on some assumptions, the simplified calculation formulas of ultimate load-carrying capacity and flexural rigidity of PPC beams strengthened with U-shaped steel plates were proposed. The results indicate that the height of the sided- plate may not exceed one-third of the heigth of the beam. The increment of initial damage degree and the decrement of level of effective prestressing may not reduce the ultimate load-carrying capacity of the strengthened PPC beams obviously. The calculation results from the proposed formulas correlate very well with those from testing and ninlinear analysis.