动载荷下固体推进剂损伤演化原位成像研究

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YUAN Yongxiang]，LIU Yuexun1， ZHAO Meng²， WANG Long， HOU Chuantao³， WANG Xuanjun²，WU Shengchuan1 （1.StateKeybratoryofilitViclestem，outhestJongUversityengduoichind; 2.ZhijianLaboratory，RocketForce UniversityofEngineering，Xi'an7oo25，Shaanxi， China; 3. Key Laboratory ofScience and Technology on Reliability and Environmental Engineering， Beijing Institute of Structure and Environment Engineering， Beijing 1Ooo76， China）

Abstract： Structural damages insolid propelants can lead to combustion anomalies and affect ballstic performance. Utilizing synchrotronradiation X-raycomputed tomography technologyandanin-situ mechanicalloading testsystem，themacro-meso structures ofnitrate esterplasticized polyether （NEPE）solid propelant wereobserved in-situ atcompressiveratesof 0.1，1.0， and 5.0mm/s .The compressive process employed an intermitent loading mode.With loading paused each time the preset displacement was reached to enablescaning imaging，therebycapturingthestateof the propelantat specific phases during compression.Follwing the in-situ imaging experiment，the tomographic images of the samples were processed through projection correction and phase recovery using PITRE and PITRE_BM software，followed by image bit-depth conversion to obtain8-bit2Dgrayscale slices.Through 3Dreconstruction，thetypical damagesand evolutionary behaviorsofthe solid propellant wereanalyzed，exploring the macroscopic deformationas wellasthe distribution and propagation pattemsof interalmicro-cracks.Resultsindicatethat most micro-cracksnucleateand growatthe interface between filedparticlesand the matrix， with meso-pore evolution being rate-dependent. Unlike the continuous damage growthunder tensile loading，the nucleation，growth，andclosureof poresoccursimultaneouslyduringcompresion.Under high-rateuiaxialcopressive loading，thesolidpropelantexibitscharacteristictrumpet-shapeddeformation，withspatiallydistributedcrackspriarily located around the propellant.Macroscopic surface damage results from micro-crack propagation betwee near-surface particlesandthematrix，withrackpropagationrelatedtothespatiallocationoffiledparticles.Transversalandaxialcrack propagation modes existunderdynamiccompressveloading，withthe transitionfromverticall tohorizontallyorientedcracks in the matrix leading to crack closure.

Keywords：solid propellant;in-situ dynamiccompression;damage rate-related behavior; internal damage evolution; synchrotron radiation 3D tomography

固体推进剂是一种典型的非均相颗粒增强复合材料，广泛用于先进航空航天装备动力系统[1-4]。（剩余14490字）