CFRP预浸料由于优异的力学性能、工艺实施性强等特点,常用来修复受损的航空金属构件,然而由于金属、胶层和补片的物理化学性质差异,成型后在贴补区域往往会引发固化残余应力并产生变形,对贴补结构承载性能造成影响。本文针对残余应力和固化变形的影响开展研究,设计了钛合金损伤构件CFRP单面贴补修复的拉伸试验,同时建立了从共固化胶接到准静态拉伸的多阶段数值分析方法。通过试验与仿真结果的综合分析,厘清了固化阶段胶层应变演化行为,比较了拉伸阶段应力应变曲线和损伤失效形式,探究了固化工艺对拉伸性能的影响规律。结果发现,固化过程胶层应变可分为五个阶段,且仿真与试验误差不超过20%;拉伸过程考虑残余应力和固化变形的多阶段模拟方法,与试验所得应力应变曲线更吻合,极限拉伸应力误差仅为1.39%,且仿真反映的各材料破坏形式与试验相同;在固化工艺方面,减缓升温速率、延长保温时间,有助于补片和胶层固化度提高、模量增加,并且使得承载方向上钛合金母板的拉应力降低、压应力升高,最终令结构表现出更优异的拉伸性能。
Due to its excellent mechanical properties and strong process feasibility, CFRP prepreg is commonly used to repair damaged aero-space metal components. However, the differences in physicochemical properties between the metal, adhesive layer, and patch often induce curing residual stresses and deformation in the bonded area after forming, which can affect the load-bearing performance of the repaired structure. This study investigates the effects of residual stress and curing deformation. Tensile tests were designed for single-sided CFRP patch repairs on damaged titanium alloy components, and a multi-stage numerical analysis method was estab-lished, covering the process from co-curing bonding to quasi-static tensile loading. Through comprehensive analysis of experimental and simulation results, the strain evolution behavior of the adhesive layer during the curing stage was clarified, the stress-strain curves and damage failure modes during the tensile stage were compared, and the influence of curing processes on tensile perfor-mance was explored. The results show that the strain in the adhesive layer during curing can be divided into five stages, with a simu-lation error of less than 20% compared to experimental data. The multi-stage simulation method, which accounts for residual stress and curing deformation, yields stress-strain curves that align more closely with experimental results, achieving an error of only 1.39% in ultimate tensile stress. Additionally, the failure modes of different materials observed in the simulation matched those in the experiments. Regarding curing processes, reducing the heating rate and extending the dwell time improved the curing degree and modulus of the patch and adhesive layer. This also reduced tensile stress and increased compressive stress in the titanium alloy sub-strate along the loading direction, ultimately enhancing the overall tensile performance of the structure.