Drilling glass fiber reinforced polymer matrix (GFRP) composites typically causes burrs, splintering, and microcracks within the GFRP structure, as well as delamination, fiber pull‐out, and thermal degradation of the polymer matrix. Designing and manufacturing molded‐hole GFRP components, as opposed to drilling, has recently been proposed as a promising method for overcoming the issues associated with drilling, for which there is limited research. Specifically, the mechanical response of molded‐hole GFRP has not been fully addressed in the literature. In the present study, molded and drilled GFRP composites with epoxy matrix were fabricated by hand lay‐up, and then the samples were analyzed utilizing experimental and numerical analysis techniques. Stress and strain analyses of GFRP samples were performed in Ansys Transient Structural Analysis. Although the fiber orientations of the layer geometries [0°/90°] and 3D models were the same, an additional layer was defined in the direction of the fiber orientation [45°/−45°] of molded‐hole composites to simulate the fiber accumulation effect. Experimental findings revealed that the flexural strength of molded composites was 12% greater than that of drilled composites. According to the numerical analysis, 98.7% proximity was achieved between the experimental and numerical results. Thus, the present study has provided numerical modeling to understand the flexural strength of molded composites for the first time, which will contribute to the increased use of molded composites in numerous applications in the fields of aerospace, automotive, and marine.Highlights Drilled‐ and molded‐hole GFRP composites were produced by hand lay‐up. Flexural properties of the composites were examined via 4P bending tests. Flexural strength of molded composites was higher than that of drilled ones. 98.7% proximity was achieved between the experimental and FEM results. A unified FEM method is proposed for the molded‐hole composites.

中文翻译：

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钻孔和模压孔玻璃纤维增​​强聚合物基体 (GFRP) 复合材料的实验和数值分析

对玻璃纤维增​​强聚合物基体 (GFRP) 复合材料进行钻孔通常会导致 GFRP 结构内出现毛刺、碎裂和微裂纹，以及聚合物基体分层、纤维拔出和热降解。与钻孔相比，设计和制造模制孔 GFRP 部件最近被认为是克服钻孔相关问题的一种有前景的方法，但目前对此的研究有限。具体而言，模孔 GFRP 的机械响应尚未在文献中得到充分解决。在本研究中，通过手糊法制造了具有环氧树脂基体的模制和钻孔 GFRP 复合材料，然后利用实验和数值分析技术对样品进行了分析。在 Ansys 瞬态结构分析中对 GFRP 样品进行应力和应变分析。尽管层几何形状 [0°/90°] 和 3D 模型的纤维取向相同，但在模制孔复合材料的纤维取向 [45°/−45°] 方向上定义了一个附加层来模拟纤维堆积作用。实验结果表明，模制复合材料的弯曲强度比钻孔复合材料高 12%。根据数值分析，实验结果与数值结果之间的接近度达到98.7%。因此，本研究首次提供了数值模型来了解模制复合材料的弯曲强度，这将有助于模制复合材料在航空航天、汽车和船舶领域的众多应用中的使用增加。 钻孔和模压孔 GFRP 复合材料是通过手糊工艺生产的。 通过 4P 弯曲试验检查复合材料的弯曲性能。 模制复合材料的弯曲强度高于钻孔复合材料。 实验结果与 FEM 结果之间达到 98.7% 的接近度。 针对模孔复合材料提出了一种统一的有限元方法。