为了全面了解复合材料的固化特性,在对碳纤维增强树脂基复合材料固化变形进行数值仿真分析的基础上,将自行设计的光纤Bragg光栅(FBG)传感器埋入复合材料中,实时在线监测复合材料固化过程中温度和应变的演变。预浸料铺层方式为[011/9011],分别在层合板0°和45°方向的典型位置埋入FBG温度和应变传感器,采用热模压方式固化成型复合材料层合板,并对成型后的层合板进行连续2次降温处理,实时记录固化过程中FBG传感器中心波长的变化。结果表明:在相同的温度条件下,复合材料在第1次降温初始阶段的压应变绝对值明显小于在第2次降温初始阶段的压应变绝对值,表明复合材料在第1次降温过程中仍在进行FBG传感器可检的"后固化"反应;此外,层合板变形的FBG传感器监测数据与有限元模拟结果吻合良好。因此,采用内埋FBG传感器的方法能够实时监测复合材料固化过程,为更全面地分析复合材料固化特性提供了一种可靠有效的方法。
In order to fully understand the curing properties of composites,on the basis of the numerical simulation and analysis for the curing induced deformation of carbon fiber reinforced resin matrix composites,self-designed fiber Bragg grating(FBG)sensors were embedded in the composite to real time on-line monitor the temperature and strain evolutions during the curing process of composite.The stacking sequence of prepreg was [011/9011].The FBG temperature and strain sensors were embedded in the typical positions of the laminate along 0°and 45°directions,respectively.The composite laminate was cured and molded by hot molded pressing method,and two continuous cooling stages were conducted on the laminate after molding.The changes for central wavelength of FBG sensors during the curing process are recorded in real-time.The results show that the absolute value of the composite compression strain at the first cooling early stage is obviously less than the absolute value of the compression strain at the second cooling early stage under the same temperature conditions,which indicates that the composite still proceeds the"post curing"reaction which can be detected by FBG sensors at the first cooling stage.Besides,the deformation monitoring data of FBG sensors for laminates match well with the finite element simulation results.Therefore,using the method of embedded FBG sensors can monitor the curing process of composites real-time,which provides a reliable and effective method for analyzing the curing characteristics of the composites more comprehensively.