纤维增强树脂基复合材料结构件的残余应力问题是制约其在航空航天、汽车和建筑领域大规模应用的关键问题.复合材料固化过程中温度场和固化度场的非均匀性是引起残余热应力和固化收缩应力的重要因素.为了探讨纤维复合材料结构件在固化成型过程中固化工艺温度、热传导系数、对流换热系数及结构件厚度对固化均匀性的敏感程度,采用数值模拟分析了这4个关键参数对温度场和固化度场均匀性的影响规律.模拟结果表明:升高固化工艺温度,复合材料温度场的非均匀性增大,固化度场的非均匀性减小;增大对流换热系数和热传导系数,复合材料温度场和固化度场的非均匀性减小;增加复合材料结构件的厚度,复合材料温度场和固化度场的非均匀性增大.在此基础上,应用Morris全局灵敏度分析方法对4个关键参数对复合材料固化均匀性的影响程度进行定量分析,得到固化均匀性的影响因素按灵敏程度由大到小的顺序为:结构件厚度、热传导系数、固化工艺温度、对流换热系数.
Residual stress problem in fiber reinforced resin matrix composite structures is a key issue to restrict their large-scale applications in aerospace, automobile and architecture fields. Non-uniformity of temperature and curing degree fields during curing process of composites is an important factor in causing residual thermal stress and curing shrinkage stress. In view of investigating the sensitive degree of curing process temperature, thermal conduc- tivity coefficient, convective heat transfer coefficient and thickness of structure to curing uniformity during curing process of fiber composite structures, the influence rule of the [our key parameters on uniformity of temperature and curing degree fields was analyzed by numerical simulation. The simulation results show that the non-uniformity of the temperature field of composites increases and the non-uniformity of the curing degree field decreases when raising the curing process temperature; the non-uniformity of the temperature and curing degree fields both decrease when increasing convective heat transfer coefficient and thermal conductivity coefficient; the non-uniformity of the temperature and curing degree fields increase when increasing the thickness of composite structure. On these basis, the influence degree of the four key parameters on curing uniformity of composites was quantized by Morris global sensi- tivity analysis method. The sensitive degree order of curing uniformity corresponding to the four key parameters from high to low is as follows: thickness of structure, thermal conductivity coefficient, curing process temperature, convective heat transfer coefficient.