论文部分内容阅读
为研究Kevlar 49芳纶纤维布增强环氧树脂复合材料在中等应变率和不同温度耦合作用下的力学响应和断裂行为,首先,利用MTS液压伺服高速机在不同初始应变率(25、50、100、200s-1)和温度(-25、0、25、50、100℃)下对芳纶纤维增强复合材料(AFRP)进行单向动态拉伸测试;然后,采用Weibull分析模型量化了拉伸强度在不同应变率和温度下的离散程度。结果表明:在相同温度(25℃)下,随着应变率的增加,弹性模量和拉伸强度均先增大(初始应变率介于25~50s-1范围内)后减小(初始应变率介于50~200s-1范围内),极限应变则呈现出相反的变化趋势,而韧性随应变率的变化幅度不大;在相同初始应变率(25s-1)下,与在25℃下的情况相比,温度的升高或降低均会造成弹性模量的降低,在温度为100℃时,极限应变显著增加,而拉伸强度和韧性均不会随温度的变化而发生明显改变。对AFRP断裂形态进行的对比分析表明不同试验条件下AFRP的断裂形态基本相同,均呈现出较为平整的断裂面。所得结论可为AFRP在极端载荷和环境作用下的理论研究和应用提供依据。
In order to study the mechanical response and fracture behavior of Kevlar 49 aramid fiber reinforced epoxy resin composites under medium strain rate and different temperature coupling effects, firstly, using MTS hydraulic servo high speed machine under different initial strain rates (25, 50, 100 , 200s-1) and temperature (-25, 0, 25, 50, 100 ℃) for the uniaxial dynamic tensile testing of aramid fiber reinforced composites (AFRP) Dispersion at different strain rates and temperatures. The results show that both the elastic modulus and the tensile strength first increase (the initial strain rate ranges from 25 to 50 s-1) and then decrease with the increase of the strain rate at the same temperature (25 ℃) Rate ranged from 50s to 200s-1), the ultimate strain showed the opposite trend, but the change of ductility with strain rate was insignificant. Under the same initial strain rate (25s-1) Compared with the case of temperature rise or decrease will cause a decrease in elastic modulus, the temperature at 100 ℃, the ultimate strain increases significantly, but the tensile strength and toughness will not change significantly with the temperature changes. The comparative analysis of AFRP fracture morphology shows that fracture morphology of AFRP is basically the same under different experimental conditions, showing relatively flat fracture surface. The conclusion can provide theoretical basis for the theoretical research and application of AFRP under the action of extreme load and environment.