碳纤维布加固高强度钢筋混凝土梁的短期挠度分析

根据在役钢筋混凝土梁的受力特点,采用有限元软件建立梁的分离式有限元模型,对梁加固和加载全过程进行模拟,综合比较分析了一次加载和二次加载对加固梁挠度的影响。4根梁的模拟计算结果比较显示,有限元方法有较好的精度。建立了适于工程设计的加固梁的挠度计算公式,计算结果与进一步的非线性有限元分析结果表明,粘贴碳纤维布可有效地提高高强度钢筋混凝土梁的抗弯刚度,并能延缓裂缝的扩展;数值模拟值与计算值有较好的一致性;建立的分离式有限元模型较真实地反映了梁的受力情况,由此得出的荷载-挠度关系曲线较真实地反映了梁的变形规律,为工程设计提供了可参照的方法。

ANALYSIS OF SHORT-TIME DEFLECTION OF HIGH STRENGTH REINFORCED CONCRETE BEAMS STRENGTHENED WITH CARBON FIBER SHEET

According to the characteristic of the force bearing of the reinforced concrete beams in commission,the software was adopted to establish the separate finite element model of the beams,and the strengthened beams and the whole process of loading were simulated,and the effects of first and secondary loading on the deflection of strengthened beams were surveyed.The comparison between the simulation results and the calculation results of four beams showed that the proposed method was a precise numerical tool.The formulas for calculating the short-time deflection of the strengthened beams were established for engineering design.The calculation results and the results of further non-linear finite element analysis showed that the stiffness of the high strength reinforced concrete beams could be improved effectively by using bonded carbon fiber sheet,and the development of crack could be delayed.The numerical calculation values correspond well with the theoretical values.The established separate finite element model could truly reflect the force bearing of the beams.Therefore,the load-deflection relation curves resulted from the numerical calculation truly reflect the deformation rule of the beams.They provided good reference for engineering design.