金属裂纹板复合材料单面胶接修补结构应力分析

Stress analysis of one-sided adhesively bonded composite repair of cracked metallic plate

考虑金属裂纹板复合材料单面胶接修补结构的几何非线性和边界条件,建立了考虑弯曲变形单面修补结构力学分析模型,计算出承受面内载荷时修补结构的弯矩和挠度,将补片自由端和金属板裂纹处的弯矩作为胶层应力控制微分方程的边界条件,推导出剪应力和剥离应力的解析解,及裂纹张开位移的表达式,并与有限元数值结果进行对比。分析结果表明,胶接修补结构应力分析理论模型和相关简化假设合理、正确。利用所建立的解析模型研究了金属裂纹复合材料单面胶接修补结构的应力分布特点及胶层主导破坏模式的失效机制,为胶接修补结构的承载能力分析以及结构改进设计提供了一定的理论依据。

A stress analysis model involving geometric nonlinearity and boundary conditions was developed to characterize adhesive stress distribution of adhesively bonded composite repair structures.The bending moment and the transverse deflection under tensile load were calculated.The bending moment at the ends of the overlap was required as boundary conditions of the differential equations governing the adhesive stresses.The solutions for induced adhesive peel stresses and shear stress were obtained,and the displacement along the mid-plane of the cracked plate was calculated.The finite element analysis was conducted to validate the present closed-form solutions.The numerical results indicate that the analytical solutions and their simplifications correlate very well with the nonlinear finite element computations.The present mathematical techniques and analysis approaches are critical to the successful design,analysis and implementation of bonded repairs.