【作者】 谷有法；

【导师】 王海军； 孙海霞；

【作者基本信息】 沈阳工业大学 ， 结构工程， 2010， 硕士

【摘要】 碳纤维布作为一种新型的加固材料,使用越来越普遍。由于它具有轻质、高强、施工便利等优点,使得其在混凝土结构加固领域得到了大量应用。在理论分析中,对二次受力情况下碳纤维布加固钢筋混凝土梁的受弯性能进行了研究。根据分析,提出了在正截面承载力计算时CFRP应乘以强度折减系数ψ,并建立了正截面承载力计算表达式。在数值分析中,本文共对20根截面尺寸为150mm×300mm,长为2000mm的梁进行了数值模拟,其中2根为对比梁,6根为一次加固梁,12根为二次加固梁。混凝土强度等级为C30,主要变化参数为初始荷载、配筋率、CFRP加固层数及粘贴长度。模拟分析结果表明,加固后梁的正截面承载力和刚度都有了显著提高。加固梁的承载力与CFRP粘贴层数有很大的关系。CFRP粘贴层数越多,加固梁的承载力提高越大,但提高的幅度与粘贴层数并不是线性增长的,随着粘贴层数的增多增加的幅度越来越小。CFRP粘贴长度越长,对梁的承载力提高越大,但并不是越长越好。根据对结果的分析,本文认为当CFRP粘贴长度为纯弯段加两倍梁高范围内时加固效果更明显。最后,在理论分析、数值模拟及试验验证的基础上,给出了CFRP的强度折减系数值和正截面承载力计算表达式。更多还原

【Abstract】 Recently, a new composite material named Carbon Fiber Reinforced Plastic (CFRP) is becoming increasingly popular as a kind of reinforcement material. It is widely used in the field of reinforcement region of concrete structures because it has many advantages such as high tensile strength, high modulus of elasticity, lightweight, corrosion resistance and good workability.In the theoretical analysis,the flexural behavior of reinforced concrete(RC) beams reinforced by CFRP under quadratic loading are studied in this paper. According to analysis,the calculation expression of normal section bearing capacity of CFRP is set up, and it is put forward that strength reduction factorψshould be multiplied in the calculation of normal section bearing capacity of CFRP.In the numerical analysis, twenty simply supported beam specimens with the dimensions of 150mm×300mm×2000mm are investigated. Among them, there are two non-strengthened control beams and six RC beams reinforced with CFRP directly and twelve secondary-loading RC beams reinforced with CFRP. Concrete strength grade is C30,the main parameters is initial load,reinforcement ratio, CFRP layers and pasting length. The simulation analysis indicates that the normal section flexural bearing capacity and stiffness of beams are significantly increased after strengthened. CFRP sheet layers have effect on strengthening effect of beams, flexural bearing capacity of beams increase with the increase of CFRP sheet layers. However,the increase extent of them is not linear. Pasting length of CFRP is the longer, flexural bearing capacity increases the larger, but increase extent of the length has a reasonable scope. Analysis results show that when pasting length is the length of pure bending section plus twice the beam’s height, the strength effect is more obvious.Finally, based on theoretical analysis, numerical simulation and test verification, the strength reduction factor and the calculation expression of normal section bearing capacity of CFRP are given.更多还原