论文部分内容阅读
从光纤Bragg光栅(FBG)反射中心波长随碳纤维增强塑料复合材料(CFRP)拉伸试件表面应变变化敏感特性的角度,详细研究了拉伸过程中FBG中心波长的拉伸变化速率(即CFRP的宏观弹性模量)与复合材料内部断裂饱和状态的相关性和断裂瞬间试件表面的应变波响应特性,即:在拉伸过程中,CFRP拉伸试件的宏观弹性模量随着内部断裂的发生而不断减小,且在试件出现明显应力松弛状态前趋于平稳;应力松弛状态出现时,断裂区域表面接收的应变波响应略大于其他区域。通过设计相应排布形式,将FBG与CFRP断裂监测相结合,提出了一种基于FBG传感的CFRP断裂分阶段监测方法。该方法中传感探头直接与CFRP试件耦合,测量及传导光路全光纤化,可实现对CFRP断裂状态的绝对监测。
From the perspective of FBG reflection center wavelength with the sensitivity of surface strain of CFRP tensile specimens, the change of tensile rate of FBG central wavelength (ie, Macroscopic elastic modulus) and the internal fracture saturation state of the composite material and the moment of fracture surface strain wave response characteristics, namely: in the tensile process, CFRP tensile specimen macro-elastic modulus with the internal fracture Occurred and decreased continuously, and appeared to be stable before the specimen appeared significant stress relaxation state. When the stress relaxation state occurred, the response of strain wave received on the fracture surface was slightly larger than that of other regions. By designing the corresponding arrangement form and combining the FBG and CFRP fracture monitoring, a monitoring method of CFRP fracture based on FBG sensing is proposed. In this method, the sensing probe is directly coupled with the CFRP test piece to measure and conduct the optical fiber all-fiber, so as to realize the absolute monitoring of the fracture state of the CFRP.