Mesoscale Simulation to Study Constitutive Properties of TATB/F2314 PBX

Abstract

Material Point Method (MPM) mesoscale simulation was used to study the constitutive relation of a polymer bonded explosive (PBX) consisting of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and a fluorine polymer binder F2314. The stress-strain variations of the PBX were calculated for different temperatures and different porosities, and the results were found to be consistent with experimental observations. The stress-strain relations at different temperatures were used to develop the constitutive equation of the PBX by using numerical data fitting. Stress-strain data for different porosities were used to establish the constitutive equation by fitting the simulation data to an improved Hashion-Shtrikman model. The equation can be used to predict the shear modulus and bulk modulus of the PBX at different densities of the sample. The constitutive equations developed for TATB/F2314 PBX by MPM mesoscale simulation are important equations for the numerical simulations of the PBX at macroscale. The method presented in this study provides an alternative approach for studying the constitutive relations of PBX.

Preparation of μ-HMX/C-Based Composite Energy Composite Microspheres by Microdroplet Technology

“…where v is the settling velocity (cm/s), K is the Stokes coefficient, which is related to the morphology of the solid phase particles, g is the gravitational acceleration (cm/s 2 ), r is the particle size of the suspended particles (cm), δ s is the relative density of the suspended particles (g/cm 3 ), δ is the density of the environment (g/cm 3 ), η is the viscosity of the system (Pa•s), η 0 is the viscosity of the liquid phase (Pa•s), f is the concentration of the solid phase in the suspension system (g/mL), and f c is the maximum concentration of solid phase that can be added to the suspension system (g/mL). From the equation, it can be seen that with the increase of solid phase concentration, the concentration of the suspension system is gradually increased, and the settling velocity of the suspended particles decreases.…”

“…As a core component of military equipment, energy-containing materials have been transformed from high performance to practicality and safety, and safety has become an important criterion for measuring the performance of weapons. Improved formulation and passivation treatment is one of the important methods to improve the safety of weapons. − High-energy ammonium nitrate explosives 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) are widely used as the main charge of conventional weapons combat sections, but they suffer from problems such as irregular crystal morphology, nonuniform size distribution, and crystal defects . In the continuous production process, the morphology size and crystal quality of explosives are usually affected by factors such as the mixing efficiency of raw materials, which makes it difficult to obtain high-quality crystal products .…”

Multiscale numerical investigation of ratchet growth damage effects in PBX 9502

“…Previous mesoscale simulations have modeled PBX materials with finite elements to characterize the behavior between the grains and binder [13][14][15][16] and have modeled interfaces between crystal grains as being comprised of polymer binder [15,17,18]. However, the extent to which the binder can cover the grain interfaces is not well understood [1,15,19].…”

A General Temperature-Dependent Stress–Strain Constitutive Model for Polymer-Bonded Composite Materials

“…The need to incorporate temperature effects into the deformation behavior of PBMs has been identified in several experimental studies on a variety of materials, for example, EDC37 in the temperature range of −65 C to 60 C by Williamson et al [ 20 ], Rowanex between −60 C and 60 C by Walley et al [ 21 ], HTPB at low temperatures by Chen et al [ 22 ], short carbon-fiber-reinforced polyether-ether-ketone (SCFR/PEEK) composites between 20 C and 235 C by Zheng et al [ 23 ], epoxy mortar at temperature between 80 C to 210 C by Vecchio et al [ 24 ], nanoparticle/epoxy nanocomposites between 23 C to 53 C by Unger et al [ 25 ], and many others [ 26 , 27 ]. Several models have been reported to describe the mechanical responses of PBM under different temperatures, including the elastic–plastic fracture-mechanism-based model using the glass-transition temperature ( ) as a piecewise knot point with a total number of 39 parameters [ 28 ], temperature-dependent mesoscale interface-based model [ 29 ], and the temperature-dependent visco-hyperelastic model [ 30 ]. Models based on the concept of temperature correction factor and its variants have been seen, for example, in [ 31 , 32 ].…”

“…Experimental evidence indicates that the mechanical behaviors of PBMs under tension and compression are quite different, and the stress–strain behavior under tension and compression may be described separately [ 20 , 21 , 28 ]. The aforementioned models in [ 29 , 30 , 31 ] were established for a single mode, and their applicability to the other mode is unknown. Other models such as the one reported in [ 28 ] and its variants requires a dozen parameters, demanding much more testing data for parameter calibration, which may not be realistic in all cases.…”