摘要
为探究复合材料结构在火灾条件下的力学响应,建立考虑基体热解和纤维软化效应的复合材料热-拉伸响应模型,通过多维数组运算对非线性方程组进行求解,研究高温下玻璃纤维/乙烯基酯复合材料的拉伸性能变化规律、预测玻璃纤维/乙烯基酯复合材料在不同拉伸载荷和单侧热流工况下的失效时间。结果表明:建立的非线性热-拉伸性响应模型,能够有效预测乙烯基酯及玻璃纤维/乙烯基酯复合材料在单侧恒定热流下的拉伸性能。通过模型预测曲线可知,玻璃纤维/乙烯基酯复合材料拉伸强度随温度的下降主要分为两个阶段:第一阶段为其在玻璃化转变温度附近快速下降;第二阶段为材料基体完全玻璃化转变后,玻璃纤维/乙烯基酯复合材料拉伸强度的缓慢下降。另外,随着拉伸载荷的增加,玻璃纤维/乙烯基酯复合材料失效时间迅速缩短,且失效时间随拉伸载荷变化情况在不同热流密度下具有相同的趋势。在相同拉伸应力下,热流密度的下降可延长材料的失效时间。在80%室温强度的拉伸应力下,层合板在10 kW/m^(2)下的失效时间较75 kW/m^(2)延长了300 s。在10 kW/m^(2)条件下,施加拉伸应力低于50%室温强度时,层合板在长时间内不会发生失效。
To explore the mechanical response of composites under fire conditions,a thermal-tensile response model for polymer composites considering matrix pyrolysis and fiber softening effects was developed.Nonlinear equations were solved using multidimensional array operations to research the variation of tensile performance of glass fiber/vinyl ester composites at high temperature and to predict the failure time under different tensile loads and one-sided heat flux conditions.The results indicate that the developed nonlinear thermal-tensile response model can effectively predict the tensile behaviour of vinyl ester and glass fiber/vinyl ester composites under unilateral steady heat flux.The results calculated using the model show that there are two distinct phases during the decrease of the tensile strength of glass fiber/vinyl ester composites with temperature decreasing:the first phase features a rapid decrease near the glass transition temperature,while the second phase shows a gradual decline following the complete glassy transition of the matrix.Furthermore,the failure time of the glass fiber/vinyl ester composites significantly decreases with increasing tensile load,displaying a consistent trend across different heat flux densities.Under constant tensile stress,the reduction in heat flux density can extend failure time of composites.Specifically,at the tensile stress of 80%of room temperature strength,the failure time of the laminate at 10 kW/m^(2)is extended by 300 seconds compared to 75 kW/m^(2).Additionally,at 10 kW/m^(2),when the tensile stress is less than 50%of the room temperature strength,the laminate will not fail for a long time.
作者
李翰
曾繁瑞
魏鹏
冯振宇
LI Han;ZENG Fanrui;WEI Peng;FENG Zhenyu(College of Safety Science and Engineering,Civil Aviation University of China,Tianjin 300300,China;Key Laboratory of Civil Aircraft Airworthiness Technology,Civil Aviation Administration of China,Tianjin 300300,China)
出处
《航空材料学报》
CAS
CSCD
北大核心
2024年第4期150-157,共8页
Journal of Aeronautical Materials
基金
中央高校基本科研基金项目(3122022056)。
关键词
玻璃纤维/乙烯基酯复合材料
高温拉伸性能
失效时间
热响应
数值计算
fiberglass/vinyl ester composites
high temperature tensile properties
failure time
thermal response
numerical calculation
