基于三维有限元模型的弹翼胶接结构胶层应力分析

摘要

目前对复合材料胶接修理结构中胶层的模拟多采用二维平面单元,不能有效模拟胶层在外载荷作用下的真实应力状态.考虑某飞行器弹翼修理时形成的复合材料双面胶接结构承受载荷后处于三维应力状态的情况,建立了该修理结构的三维有限元模型,计算出单向拉伸条件下胶层的剪应力,并与Hart-Smith解析解进行对比.分析结果表明三维有限元模型正确、合理.利用所建立的模型分析胶层的剪应力和剥离应力的分布特点,得出胶层破坏的失效顺序,为胶接修理结构的承载能力分析以及结构改进提供参考依据.%At present, the simulation of the adhesive layer in the composite adhesive repair structure mostly adopts a two-dimentional planar element, which cannot effectively simulate the true stress state of the adhesive layer under the action of the external load. A three-dimensional finite element model is established for analyzing the three-dimensional stress state of adhesively bonded composite repair structures. The adhesive shear stress is calculated under uniaxial tensile loading condition, and compared with the Hart-Smith analytical solutions to validate the effectiveness of the present model. It is indicated that the finite element computation results correlate very well with those of the analytical solutions. The distributions of the adhesive shear stress and the peel stress, as well as the mechanism of the failure mode of the adhesive, are analyzed based on the finite element model. The present model and the analytical approaches may help the investigation of the load-bearing capacity of the patched structure and improve the design accordingly.