【作者】 郑国梁；

【导师】 胡白香；

【作者基本信息】 江苏大学 ， 结构工程， 2007， 硕士

【摘要】 本文在对国内外碳纤维布加固钢筋混凝土梁和未加固钢筋混凝土梁动力特性研究统计分析的基础上，参照试验结果，对钢筋混凝土梁利用碳纤维布加固前后的损伤程度及损伤位置与钢筋混凝土梁固有频率之间的关系进行了有限元模拟分析。具体进行了以下几个方面的工作：(1)根据试验构件，建立了钢筋混凝土梁的有限元模型，在无损伤状态下，对素混凝土梁、钢筋混凝土梁和碳纤维布加固钢筋混凝土梁的各阶固有频率进行了有限元计算，并与试验结果对比，研究了无损伤状态下不同混凝土梁固有频率的关系，并根据结果，验证模型的正确性。(2)利用有限元方法，分别计算了碳纤维布加固钢筋混凝土梁和未加固钢筋混凝土梁的开裂荷载，并以此荷载为幅值，对碳纤维布加固钢筋混凝土梁进行了动力谐响应分析，研究了其开裂荷载与结构固有频率之间的关系；同时研究了梁出现初始损伤(刚刚开裂状态)时和无损伤状态时，其固有频率的变化。(3)研究了碳纤维布加固钢筋混凝土梁和未加固钢筋混凝土梁在不同荷载阶段(即不同损伤阶段)损伤程度与固有频率之间的关系，与试验值进行对比，并在简支梁弯曲振动基本频率求解公式的基础上，通过归纳推导，提出了基于动力测试数据的结构损伤识别方法。(4)利用有限元程序ANSYS建立了84个损伤梁的模型，包括42个碳纤维布加固钢筋混凝土梁和42个未加固钢筋混凝土梁，利用缺口模拟损伤，通过变化缺口的高度和位置，模拟钢筋混凝土梁损伤的程度和损伤位置，根据ANSYS模态分析计算的结果，系统研究了模型梁不同损伤程度加固前后和不同损伤位置加固前后的结构损伤与固有频率之间的关系。(5)对理论分析、试验研究和有限元模拟得出的主要结论进行了详细阐述，并对结构损伤检测和碳纤维布加固提出了研究展望。更多还原

【Abstract】 According to the statistically analyzing on the dynamic behavior of reinforced concrete beam and strengthen beam with CFRP at domestic and abroad. Contrast to the experimental results, the finite element analysis and simulation have been carried out to study the relation of frequency and damage degree ,damage location of the beam.The details are as following:(1) According to test component, build the finite element model, at undamaged situation, finite element analysis have been done for the frequency of concrete beam and reinforced concrete beam and CFRP strengthened reinforced concrete beam .A comparison is made between the experimental results and simulation results, proved the accuracy of the finite element model.(2) Finite element method is made to calculate the cracking load of reinforced concrete beam and CFRP strengthened beam, and take this load as breadth value, make a dynamic harmonic analysis of the CFRP strengthened reinforced concrete beam to research the relationship between the cracking load and structural frequency. At the same time, study the structural frequency variation of the beam between first crack situation and no damage situation.(3)Research the relationship between the damage degree and frequency of the CFRP strengthened concrete beam at the different load situation, and make a comparison with the test solution, on the basis of these, conclude the fundamental formula which can solve the bend vibration frequency, bring forward a structure damage identify method based on dynamic test data.(4)Set up 84 models of damaged beams by the finite element program ANSYS, including 42 CFRP strengthened beams and 42 without strengthening beams, the gap simulate damage, through change the height and location of the gap to simulate damage degree and damage location of the reinforced concrete beam. Based on the solution of ANSYS modal analysis, systematically research the relationship between the structural damage location and damage degree with the frequency of the modal beam.(5)Finally, expatiated the main conclusion of the theoretic analysis and test study and finite element simulation. Bring forward the research expectation for structural damage detection and CFRP strengthening.更多还原