【摘要】 热隔膜预成型过程中产生的面内纤维偏转缺陷影响着复合材料构件的安装与服役。系统揭示了热隔膜预成型过程中面内纤维偏转缺陷的形成机制及其热-速耦合影响规律。基于方框剪切夹具设计的面内纤维偏转测试平台，有效隔离了传统偏轴拉伸测试中因层间接触引起的面外干扰因素，实现了单向碳纤维/环氧树脂预浸料纯面内纤维偏转行为的精准表征。基于预浸料黏温本构模型，重点研究了25～120℃温度梯度及2～50 mm/min速度范围内面内纤维偏转的应变响应特性。试验结果表明：树脂基体动态黏度与纤维偏转抗力呈显著正相关；120℃时材料面内纤维偏转应力比25℃时下降约61.54%；预浸料面内纤维偏转应变速率敏感性影响偏转应力演化过程，高的偏转应变速率会促使面外屈曲提前发生；面内纤维偏转诱发的横向压缩应变场将触发压缩-偏转耦合失稳，导致预浸料面外褶皱和裂缝的产生。本研究为热隔膜预成型工艺参数优化提供了关键理论依据，也为建立温度-速率协同调控窗口奠定了科学基础。更多还原

【Abstract】 The in-plane fiber deflection defects generated by the hot diaphragm preforming process affect the installation and service of composite components. The formation mechanism of in-plane fiber deflection defects in the hot diaphragm preforming process and its thermal-velocity coupling influence law were systematically revealed. Based on the in-plane fiber deflection test platform designed by the frame shear fixture, the out-of-plane interference factors caused by inter-ply contact in the traditional off-axis tensile test are effectively isolated, and the accurate characterization of the pure in-plane fiber deflection behavior of unidirectional carbon fiber/epoxy resin prepreg was realized. Based on the viscosity-temperature constitutive model of prepreg, the strain response characteristics of in-plane fiber deflection under the temperature gradient of 25-120 ℃ and the rate range of 2-50 mm/min were studied. The experimental results show that the dynamic viscosity of the resin matrix is significantly positively correlated with the fiber deflection resistance. The in-plane fiber deflection stress at 120 ℃ decreases by approximately 61.54% compared with that at 25 ℃. The deflection strain rate sensitivity of in-plane fiber in prepreg affects the evolution process of deflection stress. The high deflection strain rate promotes the occurrence of out-of-plane buckling in advance. The transverse compressive strain field induced by in-plane fiber deflection will trigger the compression-shear coupling instability, resulting in the occurrence of out-of-plane wrinkles and cracks in the prepreg. A key theoretical basis for the optimization of hot diaphragm preforming process parameters was provided, and a scientific foundation for the establishment of temperature-rate coordinated control window was laid.更多还原