The open-hole tension (OHT) properties and failure processes of three-dimensional (3D) woven composite plates with circular, racetrack, and square holes were investigated in this study through experiments and finite element (FE) modeling. Tensile tests were performed on unnotched and notched specimens and measured via digital image correlation (DIC) to record the full-field strain fields, while micro-computed tomography (micro-CT) was employed to obtain the fracture morphologies. To predict the OHT performance, stress concentration factor (SCF), and damage propagation processes of the notched specimens, progressive damage analysis based on the FE model of a macro-meso coupling model was implemented on three open-hole plates. It was found that the OHT strength of 3D woven composites was reduced by approximately 35% compared with that of the unnotched specimen, whereas the modulus remained almost unchanged. The hole shape significantly influenced the strain distributions but had no perceptible effect on the OHT strength. The SCF of the specimen with a circular hole was 36% higher than those cases of the racetrack and square holes. Moreover, the hole-edge stress concentrations were mainly distributed on the warp yarns and became a cause for early failure. The major failure modes near the hole edge were warp breakage and pull-out.

本研究通过实验和有限元 (FE) 建模研究了具有圆形、跑道和方孔的三维 (3D) 编织复合板的开孔张力 (OHT) 特性和失效过程。对无缺口和缺口试样进行拉伸测试，并通过数字图像相关 (DIC) 测量以记录全场应变场，同时采用显微计算机断层扫描 (micro-CT) 获取断裂形态。为了预测缺口试样的 OHT 性能、应力集中系数 (SCF) 和损伤传播过程，在三个裸孔板上实施了基于宏观 - 细观耦合模型的有限元模型的渐进损伤分析。结果表明，与无缺口试样相比，3D 编织复合材料的 OHT 强度降低了约 35%，而模量几乎保持不变。孔形状显着影响应变分布，但对 OHT 强度没有明显影响。圆孔试样的 SCF 比跑道和方孔试样的 SCF 高 36%。此外，孔边应力集中主要分布在经纱上，成为早期失效的原因。孔边缘附近的主要故障模式是经纱断裂和拉出。圆孔试样的 SCF 比跑道和方孔试样的 SCF 高 36%。此外，孔边应力集中主要分布在经纱上，成为早期失效的原因。孔边缘附近的主要故障模式是经纱断裂和拉出。圆孔试样的 SCF 比跑道和方孔试样的 SCF 高 36%。此外，孔边应力集中主要分布在经纱上，成为早期失效的原因。孔边缘附近的主要故障模式是经纱断裂和拉出。