Open hole strength and damage behavior of GFRP and CFRP composites

IF 4.4 2区工程技术 Q1 ENGINEERING, MECHANICAL

Engineering Failure Analysis Pub Date : 2025-04-11 DOI:10.1016/j.engfailanal.2025.109584

Seçil Ekşi, Latif Salman, Muhammet Fatih Beşiroğlu, Muhammed Memişoğlu

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引用次数: 0

Abstract

Fiber-Reinforced Polymer (FRP) composites are increasingly attractive for advanced engineering applications. Notches in structural components are unavoidable in practical applications. Open circular holes, such as bolted connections, are an essential design feature. However, stress concentrations arise, the magnitude of which depends on the material anisotropy and the defect size in the plate. Precise evaluation tools are crucial for designing optimum, safe, lightweight structures. This study investigates the mechanical performance of open-hole Glass/Epoxy Composite (GFRP) and carbon/epoxy composite (CFRP) laminates experimentally and numerically. The effect of varying hole diameters, hole number, and fiber direction on mechanical properties and damage mechanism was investigated with tensile tests and finite element analyses. Higher strength values were obtained in the 0° fiber direction compared to 90° and 45°. The effect of the hole diameter on the tensile strength was enormous, and the strength values decreased as the hole diameter increased. It was observed that the number of holes in the fiber direction had much less effect on the stress–strain curves than the number of holes perpendicular to the fiber direction. The results showed that GFRP has lower notch sensitivity than CFRP because the strength reduction rate with hole size was lower. Open holes ’ Stress Concentration Factors (SCF) were determined with finite element analyses. Finite element analyses provided information about the initiation of damage. The normalized strength change curves according to the fiber direction, hole diameter, and hole number were obtained, and equations with a correlation coefficient of at least 90 % were developed according to these curves. Since notch sensitivity is higher in CFRP, the normalized strength is higher in GFRP than in CFRP. Failure analysis was performed for the GFRP composite with 6 mm holes. Tsai-Wu failure theory is utilized in the analysis to predict the damage evolution of open-hole composite laminates subjected to tension loads.

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GFRP和CFRP复合材料的裸眼强度和损伤行为

纤维增强聚合物（FRP）复合材料在先进工程应用中的吸引力与日俱增。在实际应用中，结构部件上的缺口是不可避免的。开圆孔（如螺栓连接）是一种基本的设计特征。然而，应力集中会产生，其大小取决于材料的各向异性和板中缺陷的大小。精确的评估工具对于设计最佳、安全的轻质结构至关重要。本研究通过实验和数值方法研究了开孔玻璃/环氧复合材料（GFRP）和碳/环氧复合材料（CFRP）层压板的机械性能。通过拉伸试验和有限元分析，研究了不同孔径、孔数和纤维方向对力学性能和损伤机制的影响。与 90° 和 45° 纤维方向相比，0° 纤维方向获得了更高的强度值。孔直径对拉伸强度的影响巨大，强度值随着孔直径的增加而降低。据观察，与垂直于纤维方向的孔数相比，纤维方向上的孔数对应力-应变曲线的影响要小得多。结果表明，GFRP 的缺口敏感性低于 CFRP，因为强度随孔尺寸的降低率较低。通过有限元分析确定了 "开孔 "应力集中因子（SCF）。有限元分析提供了有关损伤起始的信息。根据纤维方向、孔直径和孔数量获得了归一化强度变化曲线，并根据这些曲线建立了相关系数至少为 90% 的方程。由于 CFRP 的缺口敏感性较高，因此 GFRP 的归一化强度比 CFRP 高。对带有 6 毫米孔的 GFRP 复合材料进行了失效分析。分析中采用了蔡武失效理论，以预测受拉伸载荷作用的开孔复合材料层压板的损伤演变。

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来源期刊

Engineering Failure Analysis 工程技术-材料科学：表征与测试

CiteScore

7.70

自引率

20.00%

发文量

956

审稿时长

47 days

期刊介绍： Engineering Failure Analysis publishes research papers describing the analysis of engineering failures and related studies. Papers relating to the structure, properties and behaviour of engineering materials are encouraged, particularly those which also involve the detailed application of materials parameters to problems in engineering structures, components and design. In addition to the area of materials engineering, the interacting fields of mechanical, manufacturing, aeronautical, civil, chemical, corrosion and design engineering are considered relevant. Activity should be directed at analysing engineering failures and carrying out research to help reduce the incidences of failures and to extend the operating horizons of engineering materials. Emphasis is placed on the mechanical properties of materials and their behaviour when influenced by structure, process and environment. Metallic, polymeric, ceramic and natural materials are all included and the application of these materials to real engineering situations should be emphasised. The use of a case-study based approach is also encouraged. Engineering Failure Analysis provides essential reference material and critical feedback into the design process thereby contributing to the prevention of engineering failures in the future. All submissions will be subject to peer review from leading experts in the field.