PDF(Pubmed)
Abstract：
The curing of epoxy resin is a complex thermo-chemical process that is difficult to monitor using existing sensing systems. We monitored the curing process of an epoxy resin by using long-period fiber gratings. The refractive index of the epoxy resin increases during the curing process and can be measured to determine the degree of curing. We employed long-period fiber gratings that are sensitive to the refractive index of an external medium for the measurement of refractive index changes in the resin. We observed that the resonances of long-period fiber gratings increased their depth with the increased refractive index of the resin, which was well described by our simulation taking the coupling to radiation modes into account. We demonstrated that the degree of cure can be estimated from the depth of the grating resonances using a phenomenological model. At the same time, long-period fiber gratings are sensitive to temperature variations and internal strains that are induced during curing. These factors may affect the measurements of curing degree and should also be addressed.
摘要：
环氧树脂的固化是一个复杂的热化学过程，难以使用现有的传感系统进行监测。我们通过使用长周期纤维光栅来监测环氧树脂的固化过程。环氧树脂的折射率在固化过程中增加,并且可以测量以确定固化程度。我们采用了对外部介质折射率敏感的长周期光纤光栅来测量树脂的折射率变化。我们观察到，随着树脂折射率的增加，长周期光纤光栅的共振深度增加，我们的模拟很好地描述了这一点，考虑了与辐射模式的耦合。我们证明了可以使用现象学模型从光栅共振的深度估算固化程度。同时,长周期光纤光栅对固化过程中引起的温度变化和内部应变敏感。这些因素可能会影响固化程度的测量，也应加以解决。
