双轴动态压缩下C/SiC复合材料的破坏行为及能量吸收

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Failure behavior and energy absorption of C/SiC composites under biaxial dynamic compression

YANG Wenfa’， ZHU Zhiwu*1，2，LI Tao1，² （1. School of Mechanics and Aerospace Engineering，Southwest Jiaotong University，Chengdu 611756; 2.Sichuan Province Key Laboratory of Advanced Structural Material Mechanial Behavior and Service Safety，Chengdu 611756）

Abstract：Carbon fiber reinforced silicon carbide ceramic matrix composites （C/SiC）have extensive applications in the aerospace field.During theirservice，thismaterial oftenbears biaxial or even multi-biaxial dynamic loads.However，researchonthemechanicalbehaviorofthismaterialunderbiaxialdynamiccompressionisstillscarce.UsingbiaxialelectromagneticHopkinsonbars toconduct dynamiccompressiontests with diferentloading ratios（theratioofbiaxial loads），a geometric model ofthe microstructure of C/SiC composites wasconstructedandnumerical simulations were carriedout.The failure behaviorand energy absorptionof thismaterial under biaxial dynamiccompresionwereanalyzed.The distribution pater of micro-pores in the sample has a significant influence on thecrack propagation path，strength，and energy absorption ofthe material.Whentheloading ratioincreases fromO（uniaxial）to1（equal biaxialratio），the stresspeaksof the matrix，transverse fiber bundles，and longitudinal fiber bundles increase by 112.8 % ， 25.6% ，and 251 % respectively，resulting inasequential transformationof thefailure modeof thematerial from fiber fracture，fiberfracture + delaminationfailure，anddelaminationfailure，accompaniedbyachange paternof energyabsorptionrate fromO.398 toO.438and then to 0.407.

Keywords： C/SiC composites；biaxial dynamic compression；failure behavior；energy absorption

1引言

二维编织碳纤维增强碳化硅陶瓷基复合材料（C/SiC）具有高比强度、高比刚度、低密度以及耐高温等优异性能[1，2]，被广泛应用于飞行器鼻锥、前缘以及发动机热结构部件[3，4]。（剩余11688字）