摘要
为准确预测变厚度铺层夹层结构的固化变形,基于热-化学-结构多物理场耦合方法对AS4/8551碳纤维/环氧树脂复合材料-Nomex蜂窝夹层结构的固化过程进行数值模拟。考虑材料时变特性的影响,结合复合材料瞬时线弹性本构模型、细观力学理论和改进的Gibson等效理论建立起夹层结构三维有限元仿真模型,研究了结构在整个固化周期中的固化度场、温度场和应力-应变场的分布关系,并同已有的实验结果进行对比验证,最后通过解析模型分析预固化工艺对结构回弹变形的影响规律。结果表明:建立的有限元模型能够比较准确地反映结构固化过程,固化变形的平均预测误差为4.8%,最大预测误差不超过6.0%;变厚度铺层设计对较薄区域面板的固化应力影响较大,表现为沿厚度方向的向上剪切应力,在冷却阶段集中于结构端部并转化为结构翘曲;面板预固化处理削弱了固化放热和材料各向异性对夹层结构固化变形的影响,0.25预固化程度下结构最大变形的降低幅度达到14.78%。研究结果为复杂设计蜂窝夹层件制造精度的提升和工艺优化提供了重要参考。
To accurately predict the curing deformation of sandwich structures with variable thickness layup,a numerical simulation of the curing process of AS4/8551 carbon fiber/epoxy resin composite-Nomex honeycomb sandwich structure was conducted based on the thermal-chemical-structural multiphysics coupling method.Considering the influence of material time-varying characteristics,a three dimensional finite element model of sandwich structure was established by combining the transient linear elastic constitutive model of composites,micromechanics theory,and an improved Gibson equivalent theory.The distribution relationship between the curing degree field,temperature field,and stress-strain field of the structure throughout the entire curing cycle was studied.The simulation results were compared and validated against existing experimental data.Finally,the influence of pre-curing process on the structural rebound deformation was analyzed through the analytical model.The results show that the established finite element model can accurately reflect the curing process of the structure,with average prediction error of 4.8%and a maximum prediction error of no more than 6.0%for curing deformation.The variable thickness layup design has a significant impact on the curing stress of the thinner panel,resulting in upward shear stress along the thickness direction.During the cooling stage,these stresses concentrate at the ends of the structure and transforms into structural warping.The pre-curing preocess of the panels weakens the influence of curing heat release and material anisotropy on the curing deformation of the sandwich structure.At a pre-curing degree of 0.25,the reduction in maximum curing deformation reaches 14.78%.The research results provide important references for improving the manufacturing accuracy and optimizing the processes of complex designed honeycomb sandwich parts.
作者
徐景校
花宏亮
王玉魁
赵海涛
高晓初
李培智
陈吉安
XU Jingxiao;HUA Hongliang;WANG Yukui;ZHAO Haitao;GAO Xiaochu;LI Peizhi;CHEN Ji’an(School of Aeronautics and Astronautics,Shanghai Jiao Tong University,Shanghai 200240,China;AVIC Harbin Aircraft Industry Group Co.,Ltd.,Harbin 150066,China;School of Mechanical and Electrical Engineering,Harbin University of Technology,Harbin 150001,China)
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2024年第8期56-67,共12页
Journal of Harbin Institute of Technology
基金
国家自然科学基金(52075130)
黑龙江省“百千万”工程科技重大专项项目(2021ZX04A02)。
关键词
变厚度铺层
蜂窝夹层结构
多物理场耦合
数值模拟
预固化
variable thickness layup
honeycomb sandwich structure
multiphysics coupling
numerical simulation
pre-curing
