基于光纤—碳纤维测试技术的CFRP预应力梁的损伤监测研究

发布时间：2018-03-16 16:13

本文选题：碳纤维复合材料　切入点：光纤光栅传感器　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着时代发展和科技进步,工程建设的规模越来越大,数量越来越多,由此引发的结构的损伤和破坏等问题亟待解决,结构健康监测应运而生,尤其近几年来,结构智能健康监测日渐兴起。碳纤维复合材料(Carbon Fiber Reinforced Polymer,CFRP)具有质量轻、强度高、耐疲劳、自感知等特性,光纤光栅传感器(Fiber Bragg Grating,FBG)具有测量精度高,抗干扰,电绝缘性好,耐腐蚀等特性,基于CFRP和FBG的以上特性,碳纤维复合材料和光纤光栅传感器在结构智能健康监测中的研究和应用已经成为当前的热点。本文在国家自然科学基金项目“基于碳纤维材料的预应力混凝土结构自感知特性及其应用研究(51478209)”的资助下,主要研究了结合两种不同特性的自感知智能材料形成功能互补的复合式传感器件对普通混凝土结构和预应力混凝土结构的损伤监测,主要研究内容如下:(1)设计制作了FBG-CFRP传感元件,并对传感元件进行了拉伸测试,测定了元件的应变、电阻和FBG传感器的波长,分析了传感元件电阻变化率-应变、波长-应变之间的关系,结果表明:在小荷载阶段,传感元件的电阻变化率和应变变化之间近似满足线性关系,线性拟合度达到0.95以上;传感元件中的FBG传感器的传感性能未发生改变,应变灵敏度都保持在1.2pm/??,线性拟合相关系数都在0.9998以上。(2)将FBG-CFRP传感元件埋入三组普通钢筋混凝土梁中,对混凝土梁进行了三分点加载试验,测定了传感元件的电阻、应变,观察了混凝土梁的开裂以及破坏过程,分析了传感元件电阻变化率-荷载、应变-荷载之间的关系,研究了应变突变和混凝土梁开裂之间的关系,结果表明:FBG-CFRP传感元件可对普通混凝土梁的荷载、应变、损伤等进行监测。(3)将FBG-CFRP传感元件埋入后张拉法浇筑的无粘结式CFRP预应力梁中,对预应力梁进行了三分点加载试验,测定了传感元件的电阻、应变,观察了预应力梁的开裂及破坏过程,分析了传感元件电阻-荷载、电阻变化率-荷载、应变-荷载之间的关系以及CFRP预应力筋的应变-荷载关系,研究了应变突变与预应力梁开裂之间的关系,结果表明:FBG-CFRP传感元件的测试结果与实际预应力梁的损伤及破坏过程相符。
[Abstract]:With the development of the times and the progress of science and technology, the scale and quantity of engineering construction is becoming larger and larger, the damage and damage of structure caused by this problem need to be solved urgently, and structural health monitoring emerges as the times require, especially in recent years. Carbon Fiber Reinforced Polymeric carbon fiber reinforced polymer (CFRP) has the characteristics of light weight, high strength, fatigue resistance, self-sensing and so on. Fiber Bragg Grinding Fiber Bragg grating (FBG) sensor has high measurement accuracy, anti-interference and good electrical insulation. Corrosion resistance, etc., based on the above characteristics of CFRP and FBG, The research and application of carbon fiber composites and fiber Bragg grating sensors in structural intelligent health monitoring has become a hot topic at present. The National Natural Science Foundation of China "Prestressed concrete junction based on carbon fiber material" The study of Self-sensing and its applications (51478209) ", The damage monitoring of ordinary concrete structures and prestressed concrete structures by composite sensing devices with complementary functions formed by two kinds of self-sensing intelligent materials with different characteristics is studied. The main research contents are as follows: (1) the FBG-CFRP sensor element is designed and fabricated, and the strain, resistance and wavelength of the FBG sensor are measured by the tensile test of the sensor element, and the rate of change of the resistor of the sensor element is analyzed. The relationship between wavelength and strain shows that at the stage of small load, the linear relationship between the change rate of resistance and strain of sensor element is approximately linear, and the linear fitting degree is more than 0.95; The sensing performance of the FBG sensor in the sensor element has not changed, and the strain sensitivity is maintained at 1.2 pm / r? ? The linear fitting correlation coefficients are all above 0.9998. The FBG-CFRP sensing elements are embedded in three groups of ordinary reinforced concrete beams. The three-point loading test is carried out on the concrete beams, and the resistance and strain of the sensing elements are measured. The cracking and failure processes of concrete beams are observed. The relationship between resistance change rate and load and strain load of sensing elements is analyzed, and the relationship between strain mutation and cracking of concrete beams is studied. The results show that the FBG-CFRP sensing element can be used to monitor the load, strain and damage of the ordinary concrete beam. The FBG-CFRP sensing element is embedded in the unbonded CFRP prestressed beam, and the three-point loading test is carried out on the prestressed beam. The resistance and strain of the sensing element are measured, the cracking and failure process of the prestressed beam are observed, and the resistance-load, resistance change rate and load of the sensing element are analyzed. The relationship between strain and load and between strain and load of CFRP tendons is studied. The results show that the measurement results of the FBG-CFRP sensor are consistent with the damage and failure process of the prestressed beam.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU37

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