Abstract The shear strength of composite secondary bonded single-lap joints was studied in this article. To optimize the adhesive thickness and ensure stable mechanical properties, an improved mold was applied. Based on this mold, a total of 15 specimens (180 samples) were examined and they were fabricated with various overlap lengths, curing pressures, adhesive thicknesses, ply angles, and surface treatment methods. The experimental results indicated that the improved mold not only significantly increased the uniformity of the adhesive thickness but also enhanced the shear strength of the joints and the shear strength was improved by approximately 13% compared to that of conventional methods. Moreover, the shear strength was decreased in specimens with increased overlap lengths and increased in samples with an increased curing pressure. Furthermore, the shear strength of the specimens was also affected by the adhesive thicknesses, ply angles, and surface treatment methods. The mechanisms can be ascribed to the effect of the fabrication method on the failure mode. A facile platform for optimizing these parameters is provided in this article. Based on this platform, the shear strength of the joints was enhanced to 33.5 MPa.

中文翻译：

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不同制造方法复合二次粘结单搭接接头的抗剪强度

摘要 本文研究了复合二次粘结单搭接接头的抗剪强度。为了优化粘合剂厚度并确保稳定的机械性能，应用了改进的模具。基于该模具，总共检查了 15 个样品（180 个样品），并使用不同的重叠长度、固化压力、粘合剂厚度、层板角度和表面处理方法制造了它们。实验结果表明，改进后的模具不仅显着提高了胶粘剂厚度的均匀性，而且增强了接头的剪切强度，剪切强度比传统方法提高了约13%。此外，随着重叠长度的增加，样品的剪切强度降低，而固化压力增加的样品的剪切强度增加。此外，试样的剪切强度还受粘合剂厚度、层板角度和表面处理方法的影响。这些机制可以归因于制造方法对失效模式的影响。本文提供了一个用于优化这些参数的简便平台。基于该平台，接头的抗剪强度提高到33.5 MPa。