Abstract：This paper presents experimental and finite element simulation investigation into the longitudinal compressive failure behavior of unidirectional carbon fiber reinforced aluminum matrix (UD-CF/Al) composites at room and elevated temperatures. First, UD-CF/Al composites with M40J carbon fibers as reinforcement and Al-10Mg alloy as matrix were prepared via the vacuum pressure infiltration process, and longitudinal compression tests were carried out at 25?℃ and 300?℃, respectively. Then, based on micromechanics, we develop a finite element model that incorporates fiber strength dispersion (Weibull distribution), initial fiber misalignment defects, interfacial damage evolution, and the elastoplastic mechanical behavior of the matrix. The effects of fiber strength dispersion on simulation accuracy, the influence of room and high temperatures on the compressive mechanical response, as well as the progressive damage evolution and corresponding failure mechanisms of the composites are systematically analyzed. The results demonstrate that the model accounting for fiber strength dispersion yields a macroscopic longitudinal compressive response that is in better agreement with experimental measurements, thereby significantly enhancing the accuracy of numerical predictions. At both room and elevated temperatures, the composite exhibits a typical progressive failure sequence: interfacial damage initiates first, followed by the emergence and development of matrix damage, and fiber kinking acts as the dominant final failure mechanism. Compared with room temperature, under high-temperature conditions, matrix softening and interfacial degradation lead to a significant decrease in the longitudinal compressive modulus and strength of the composite. Interfacial damage initiates earlier but propagates slowly, accompanied by relatively minor matrix damage. The fiber misalignment angle increases rapidly during the evolution process but remains small at the final failure state. Moreover, the composite is more prone to structural instability under high temperature, resulting in the formation of a wider kink band. This study provides a reliable numerical analysis approach and theoretical foundation for the structural design, mechanical performance evaluation, and reliability assessment of fiber-reinforced metal matrix composites serving in high-temperature environments.
2026, Vol. 47 
