C/SiC与TC4层合结构的斜侵彻破坏行为和机理

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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

超高速飞行器在高马赫数飞行时，气动热导致其局部表面达到 1000‰ 以上的高温，这些局部高温区域通常采用耐高温表面层（C/SiC、C/C、SiC/SiC 等）和金属底衬层（钛合金、镍基合金等）的层合结构[1-2]。（剩余15838字）