【摘要】 对SiC_f/TC17复合材料开展室/高温纵向拉伸试验，研究不同温度的拉伸性能，通过断口形貌分析阐释断裂机制，建立本构模型描述其拉伸行为。结果表明：SiC_f/TC17的断裂强度随着温度升高而降低，同时应力应变曲线的非线性段增加；室温（25℃）的断裂机制主要是反应层断裂和纤维随机断裂，而高温下出现大规模的纤维拔出与界面脱黏、基体韧性断裂和多纤维断裂；不同强度预测模型的结果表明：25℃下材料的断裂模式以局部承担载荷为主，而高温更符合全局承担模型；所提出的耦合纤维累积损伤的本构模型很好地模拟了25℃和450℃的应力应变曲线。最后基于试验所得拉伸性能，开展了叶环结构的应力应变分析和静强度校核，在典型服役温度下，叶环结构具有较高的强度储备系数。更多还原

【Abstract】 Longitudinal tensile tests were carried out on SiC_f/TC17 composites at room/high temperature to investigate the tensile behaviors.The damage evolution and failure mechanisms were revealed based on microscopic fracture morphology analysis.Afterwards,a constitutive model was developed to describe the tensile behaviors of SiC_f/TC17 composites.The results showed that the ultimate tensile strength of SiC_f/TC17 composites decreased with the increasing temperature,while the nonlinear segment of the stress-strain curve increased.The major failure mechanisms at room temperature (25℃)lied in multiple fractures of the interfacial reaction layer and random breakage of weak fibers,whereas large-scale interface debonding and fiber pullout,matrix cracking and fiber breakage were more common at high temperatures.The results of different strength-predicted models demonstrated that the failure mode of SiC_f/TC17 composites at 25℃was controlled by local loading sharing,while the high-temperature ultimate tensile strength was more consistent with the global loading sharing model.The stress-strain curve of SiC_f/TC17 composites was simulated by the proposed constitutive model with coupling fiber cumulative damage.The simulation results exhibited a trend similar to that of the experimental data at 25℃and450℃.Finally,based on the tensile properties obtained from the tests,finite element stress-strain analysis and static strength calibration of the TMCs blade-ring structure were carried out.The result indicated tha the blade-ring structure exhibited a significantly elevated strength reserve factor at the typical service temperature.更多还原