摘要
为了研究玄武岩纤维(BF)增强环氧树脂单向复合材料在不同环境温度下的拉伸疲劳性能,进行了一系列试验测试和寿命预测。首先,通过静态拉伸试验获得了它在室温下的强度极限σ_(m);然后,在三个环境温度(室温、50℃和70℃)下分别进行四个应力水平(75%σ_(m)、70%σ_(m)、65%σ_(m)和60%σ_(m))的拉-拉疲劳试验,测得了相应应力水平下的疲劳寿命,获得了相关的疲劳刚度数据;最后,基于指数形式的S-N曲线预估了其在不同环境温度条件下的疲劳极限。结果表明:同一环境温度下,玄武岩纤维复合材料疲劳寿命随着应力水平降低呈规律性增加;相同应力水平下,其疲劳寿命随着温度的升高呈明显降低趋势,且随着温度增加,疲劳破坏断口纤维拔丝明显增多;在拉-拉疲劳的初始阶段,温度越高,刚度退化越明显,退化速率越大;比较发现,室温条件下玄武岩纤维复合材料疲劳性能优于玻璃纤维复合材料。
In order to study the tensile fatigue properties of basalt fiber(BF)reinforced epoxy unidirectional composites at different ambient temperatures,a series of experimental tests and life prediction were carried out.Firstly,the maximum failure stressσ_(m) at room temperature was obtained by static tensile test.Then,the tensiontension fatigue tests with stress levels of 75%σ_(m),70%σ_(m),65%σ_(m) and 60%σ_(m) were carried out at three ambient temperatures(room temperature,50℃,and 70℃),respectively,and the corresponding fatigue life cycles and obtained relevant fatigue stiffness data were achieved at different stress levels.Finally,the fatigue life at different ambient temperatures were estimated according to the exponential S-N curve.The results show that the fatigue life of basalt fiber composite increased with the decrease of stress level under the same temperature.The fatigue life decreased significantly with the increase of temperature under the same stress level,and the fiber-drawing of fatigue fracture increased dramatically with the increase of temperature.In the initial stage of tension-tension fatigue,the higher the temperature,the more obvious the stiffness degradation and the greater the degradation rate.The comparison analysis show that the fatigue properties of basalt fiber composites is better than that of glass fiber composites at room temperature.
作者
赵古先
曹升虎
张健
ZHAO Gu-xian;CAO Sheng-hu;ZHANG Jian(Department of Engineering Mechanics,Xi'an University of Technology,Xi'an 710048,China)
出处
《复合材料科学与工程》
CAS
北大核心
2022年第3期104-109,共6页
Composites Science and Engineering
关键词
单向玄武岩纤维复合材料
温度
拉-拉疲劳
S-N曲线
寿命预测
unidirectional basalt fiber composites
temperature environment
tension-tensile fatigue
S-N curve
life prediction
