环氧树脂灌封结构固化行为数值模拟和工艺优化

依据实验测试获得E51环氧树脂的固化动力学和力学性能参数，针对特定尺寸的E51树脂灌封结构，将数值模拟与实验方法相结合，优化树脂的常温固化工艺为“二阶段”中高温固化工艺。首先采用数值模拟方法，分别比较第一段保温平台和第二段保温平台不同温度幅值和固化时间对结构内部的温度、固化度和应变的影响，优选固化工艺参数；然后基于光纤布拉格光栅(FBG)监测技术，对优选和原始固化工艺曲线的结构内部的固化温度和应变进行实时在线监测，结果表明了数值模拟的可行性，显示了通过数值仿真优选固化工艺曲线的可靠性；最后实验测试比较优选工艺和原始工艺曲线下制造的E51树脂浇注体性能，结果显示优选工艺制造的树脂浇注体的拉伸强度、压缩屈服强度、弯曲强度和冲击强度相比原始工艺制作的试样分别提高了3.9%、1.5%、14.5%和16.2%。 

Numerical simulation on cure behavior and optimization on cure cycle for encapsulation structure of epoxy resin

This paper aims at optimizing the cure cycle of specific encapsulation structures composed of E51 resin from room temperature cure cycle to medium-high “two-phase” cure cycle by means of combination of numerical simulation and experimental testing on the basis of experimentally obtained parameters of cure kinetics and mechanical properties for E51 epoxy resin. The numerical method was firstly adopted to simulate the effects of temperature magnitude and curing time in the first and second dwelling phase to internal temperature, degree of cure and strain of structure during curing to optimize the process parameter. Then the internal temperature and strain of the structure were real-time recorded using Fiber Bragg Grating (FBG) monitoring technique, and the corresponding results reveal the validity of numerical simulation, which demonstrates the reliability of the approach of optimizing the cure cycle using numerical simulation. Lastly, the properties of the casting body specimens of E51 resin manufactured with optimized and original cure cycle were compared, and the results show that the tensile strength, compressive yield strength, flexural strength and impact strength for the specimens manufactured with optimized cure cycle increase by 3.9%, 1.5%, 14.5% and 16.2% compared with the specimens manufactured with original cure cycle, respectively.