复合材料胶粘修复界面的载荷传递仿真优化

胶接修复工艺是飞机结构修理的重要工艺之一,为了研究胶黏工艺对修复效果的影响规律,探索最佳的工艺参数,本文建立胶粘修复的三维模型,利用ANSYS Workbench有限元软件对胶粘修复界面载荷传递进行分析,讨论补片材料、补片厚度、胶层剪切模量和胶层厚度对胶接修复的影响。仿真结果证明补片材料为硼/环氧树脂时,胶粘失效风险最小;补片较厚时,胶接修复效果好,但补片过厚会削弱胶接修复的效果;胶黏剂剪切模量越大越有助于损伤区域的修复,工程应用中建议选用剪切模量较高的胶黏剂;胶层较厚时会增大胶层发生缺陷的概率从而减弱修复效果,建议合理选取厚度较小的胶层。最后提出修复界面的表面处理、复合材料端部的溢胶以及倒角处理均有益于修复结构的载荷传递,缓和胶粘界面应力水平,降低胶层失效的风险。

Simulation Optimization for Load Transfer of Composite Bonding Repair Interface

Composite bonding repair was one of the important processes for aircraft structural repair and the scientific bonding process design was an important factor to ensure the repair effect of aircraft damage structure.In order to study the influence of adhesive technology on repair and explore the best bonding process parameters,the finite element model was established to analyze the load transfer behavior of composite bonding repair interface by ANSYS workbench.The material and thickness of the patch,shear modulus and thickness of adhesive layer were taken to discuss the effect on bonding repair.The simulation results show that when the patch material is boron epoxy resin,the risk of adhesive failure is the smallest.When the patch is thicker,the effect of bonding repair is good,but too thick patch will weaken the effect of bonding repair.The larger shear modulus of the adhesive,the better the repairing of the damaged area.It is suggested to choose adhesive with high shear modulus in engineering application.The thicker layer will increase the probability of defects in the layer so as to weaken the repair effect.Therefore it is suggested to select the layer with minimum thickness reasonably.At last, the surface treatment of the repair interface,the glue overflow at the end of the composite material and the chamfering treatment are all beneficial to the load transfer of the repaired structure,to ease the stress of the adhesive interface and to reduce the risk of layer failure.