C/SiC與TC4層合結(jié)構(gòu)的斜侵徹破壞行為和機理

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Oblique penetration failure behavior and mechanisms of C/SiC and TC4 layered structures

CHENG Ran，LI Tao，ZHU Zhiwu * （School of Mechanics and Aerospace Engineering， Southwest Jiaotong University， Sichuan Province Key Laboratory of Advanced Structural Materials Mechanical Behavior and Service Safety，Chengdu 611756）

Abstract：Toinvestigatethemesostructural response，failure modes，and failure mechanismsof thelayered structurecomposed of composite material （C/SiC）and titanium aloy（TC4）during oblique penetration，aswell as theirdependenceon penetration velocityandobliquity，experimentaland numerical studies wereconductedontheoblique penetrationof spherical projectiles into this structure at velocities ranging from 35O to 550 m/sand obliquity angles between 30° and 60° . Amesoscopicmodel ofthe C/SiCcompositewas developed，incorporating microvoids，a SiC matrix，and transverse/longitudinal fiber bundles.The Hashin criterion was employed to assess damage in thecomposite material.During penetration，the strong attenuation efectofC/SiConshock waves prevented spalltiononthebackofthe target.DelaminationandfiberfractureoccurredinthecentralregionoftheC/SiCfrontplate，formingcracksthatpropagatedobliquelytowardtherear.SignificantbendingdeformationoftheTC4rearplateonlyoccurreduponcontact with the projectile，eventuallyleading toperforation.Thepenetrationfailure modesofthislayered structureincludefiberbundlefracture，microvoidcolapse，internal delamination ofthecomposite，andinterfacedelaminationbetween C/SiCandTC4.Asthepenetrationvelocityincreases，the riseinshearstresscausesthefailuremodeoftheC/SiCcompositetoshiftfromdelaminationtofibershearfracture，withan increase in the inclinationangleand propagationdistance of obliquecracks.Asthe penetration obliquity increases，theout -of-plane velocitycomponent of the projectile decreases，reducing the bending deformation of the TC4 rear plate.Meanwhile，theinitiationof interfacedelaminationbetween C/SiCandTC4isdelayed，butthedelaminationareaincreases. Keywords： C/SiC and TC4 layered structure；oblique penetration；failure mode；failure mechanisms

1引言

超高速飛行器在高馬赫數(shù)飛行時，氣動熱導(dǎo)致其局部表面達到 1000‰ 以上的高溫，這些局部高溫區(qū)域通常采用耐高溫表面層（C/SiC、C/C、SiC/SiC 等）和金屬底襯層（鈦合金、鎳基合金等）的層合結(jié)構(gòu)[1-2]。（剩余15838字）