传统的反应注塑成型固化变形仿真研究往往忽略充模阶段的影响,难以真实反映实际工艺全过程.以某汽车车门下饰件外板简化模型为研究对象,考虑了双环戊二烯充模流动阶段的流体传热和固化反应,在傅里叶热传导方程和固化反应方程中引入对流项,建立了热-化-流-固耦合数学模型.利用COMSOL Multiphysics软件分模内和脱模两阶段模拟了外饰件的温度场、固化度场、应力应变场.对比计及充模阶段和忽略充模阶段的模拟结果,研究发现充模结束时刻温度场和固化度场已处于不均匀分布状态,Z向最大位移分别为29.5 mm和35.5 mm,两者相差16.9%.充模模温越大,两种模拟结果的差值越大.文章提出的计及充模影响的仿真过程更贴近反应注塑成型实际工艺过程.
Traditional research on solidification deformation simulation of reaction injection molding often overlooks the impact of the filling stage and cannot truly reflect the entire process of the actual process.The simplified model of an automobile door lower trim panel is taken as the research object,and the fluid heat transfer and curing reaction of dicyclopentadiene in the filling flow stage are considered.The convection term is introduced into the Fourier heat conduction equation and the curing reaction equation,and the thermal-chemical-fluid-solid coupling mathematical model is established.COMSOL Multiphysics software is used to simulate the temperature field,curing degree field,and stress-strain field of other decorative components in two stages:in mold and demolding.Comparing the simulation results considering the filling stage and neglecting the filling stage,it is found that the temperature field and curing degree field are already in an uneven distribution state at the end of filling,with the maximum displacement in the Z direction being 29.5 mm and 35.5 mm,respectively,with a difference of 16.9%.The higher the mold filling temperature,the greater the difference between the two simulation results.The simulation process taking into account the influence of mold filling proposed in the article is closer to the reaction injection molding process.