Department of Civil Engineering, Gangneung-Wonju National University, Gangneung, South Korea.
Sci Prog. 2021 Jul-Sep;104(3):368504211029451. doi: 10.1177/00368504211029451.
Fatigue of composite materials is a very complex phenomenon, to date a numerous research effort is being spent on it. Because of deficiencies in study of flexural fatigue performance basalt fiber reinforced polymer (BFRP), the main objective of this work is to investigate the flexural fatigue performance of BFRP. The laminates of 4.0 mm average thickness were fabricated using the vacuum infusion technique. Three different stress levels of (162.90, 122.24, and 81.44) MPa were considered. A failure criterion was considered to be a 20% stiffness reduction of flexural fatigue test. Also, the stiffness reduction zones in the history of fatigue specimen were investigated. The failure mode of specimen at 20% reduction stiffness was inspected. The Weibull distribution function was used to obtain the failure probabilities and scatter. The S-N curve of composite laminates was constructed using five specimens at each number of cycles. This study indicated that under fatigue loading, the stiffness degradation process of composite materials was divided into three stages: the first is the high rate of stiffness degradation at the first few thousand cycles. The second stage then takes place with slow gradual stiffness degradation, which covers a sizeable portion of the component life. Finally, more grave types of damage occur, like fiber fracture, and induce complete material failure.
复合材料的疲劳是一种非常复杂的现象,迄今为止,人们为此付出了大量的研究努力。由于对玄武岩纤维增强聚合物(BFRP)的弯曲疲劳性能研究不足,本工作的主要目的是研究 BFRP 的弯曲疲劳性能。采用真空灌注技术制造了平均厚度为 4.0mm 的层压板。考虑了(162.90、122.24 和 81.44)MPa 三个不同的应力水平。将 20%的刚度降低视为弯曲疲劳试验的失效准则。此外,还研究了疲劳试件历史中的刚度降低区。检查了刚度降低 20%的试件的失效模式。使用威布尔分布函数获得失效概率和分散度。使用五个试件在每个循环次数上构建复合材料层压板的 S-N 曲线。本研究表明,在疲劳载荷下,复合材料的刚度退化过程分为三个阶段:第一阶段是在前几千个循环中刚度的快速下降。然后进入第二阶段,刚度缓慢逐渐下降,这占据了组件寿命的很大一部分。最后,更严重的类型的损伤发生,如纤维断裂,并导致完全的材料失效。