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EN
In order to improve the safety properties of molecular perovskite energetic materials, ammonium perchlorate-based molecular perovskite ((H2DABCO)[NH4(ClO4)3], DAP)/graphene composite was prepared and characterized. Molecular perovskite DAP was prepared via a molecular assembly strategy by the facile one-pot reaction of triethylenediamine (TEDA, DABCO), perchloric acid, and ammonium perchlorate, and the DAP/graphene composite was fabricated by mechanical mixing with 10 wt.% graphene. The results demonstrated that impact sensitivity (>120 cm), friction sensitivity (25%) and electrostatic spark sensitivity (7.04 J) of the DAP/graphene composite was less sensitive than raw DAP (impact, friction and electrostatic spark sensitivity: 112.3 cm, 45%, and 5.39 J, respectively), due to the composite desensitization mechanism of graphene. This work may offer new ideas for the design and fabrication of insensitive molecular perovskite-based energetic composites.
EN
2,4-Dinitroanisole (DNAN) has excellent properties as a replacement for 1,3,5-trinitrotoluene (TNT) in melt-cast explosives, and the polymeric modifier used is critical to the mechanical modification of the DNAN/RDX energetic composite. In our research, the typical polymeric modifier acrolein-pentaerythritol resin (APER) was successfully added experimentally to the DNAN/RDX system, and the effects of interfacial interactions on the mechanical properties of these polymers in reinforcing the DNAN/RDX energetic composites were investigated by molecular dynamics simulations, scanning electron microscopy (SEM) and mechanical testing. The results showed that strong attractive interactions exist between the polymer and the explosives, wherein van der Waals forces were found to play the main role. The morphological micro-images also showed tight binding between the polymer/explosive interfaces, which supported the calculated strong interfacial interactions. The mechanical tests confirmed that adding the polymers can obviously reinforce the mechanical strength and toughness of DNAN/RDX systems. The above observations revealed that the cooperative effects of the APER polymer can help to reinforce the interfacial interactions and mechanical properties of DNAN/RDX composites, which is of importance in the formulation and mechanical evaluation of advanced energetic composites.
EN
This article deals with a non-classical scale transition devoted, in the long-run, to the prediction of the nonlinear mechanical behavior of energetic composites. A geometrical and kinematical schematization of the microstructure is defined as a conspicuous starting point for further localization-homogenization procedure. Thus, salient information on the morphology and some intraphase heterogeneity are taken into account. The first results obtained in a finite strain context for a three-dimensional periodic microstructure are compared to the finite element solution. Furthermore, the ability of the methodology to deal with viscohyperelasticity in a direct manner is illustrated. This is a significant step towards efficient mastery of the scale transition for viscoelastic aggregates, whose inherent characteristic lies in space/time local interactions and relative "long-memory" effect.
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