Two mechanical induced fracture behaviors for RDX crystalline ensembles and bulk single crystal at mesoscale are presented in this paper. First, the particles facture/crush behaviors of 5 types RDX ensembles sourced from commercial lot and ICM developed high quality lots were investigated. The measured fluctuation amplitudes of re-crystallized is about 2.4 MPa, which is much higher than that of commonly used RDX, say, 1.2MPa, and D-RDX bears the highest fluctuation amplitude of 4.4 MPa, it means that D-RDX has the highest allowable failure stress and its quality has been well improved compared to the rest of the samples. Second, the indentation induced factures of a bulk single RDX crystal was also be studied using instrumental microindenter. The regular pop in or fracture/slip was firstly reported. The elastic limits or fracture initiation stress which is related to the plastic deformation was calculated as 465 MPa that is far below the hardness of 550MPa. The mean fluctuation fracture stress during loading period is estimated approximately 10MPa. It is found that the fluctuation of the compression relates closely to the coherence strength of single particle of RDX and, that the fluctuation amplitude of D-RDX ensemble induced by compression could be 6.6MPa if excluding the void effect, which seems close to the mean fluctuation fracture stress in microindentation.
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