Deformation and failure of polymer bonded explosives under diametric compression test

Abstract

The tensile deformation and failure of polymer bonded explosives (PBXs), a particulate composite, is studied in this paper. Two HMX-based PBXs with different binder were selected for study. A diametric compression test, in which a disc-shaped specimen is loaded diametrically, was chosen to generate tensile failure in the materials. The quasi-static tensile properties and the tensile creep properties were studied by using conventional displacement transducers to measure the lateral strain along the horizontal diameter. The whole-field in-plane creep deformation was measured by using the technique of high resolution moiré interferometry. Real time microscopic examination was conducted to monitor the process of deformation and failure of PBXs by using a scanning electron microscope equipped with a loading stage. A manifold method (MM) was used to simulate the deformation and failure of PBX samples under the diametric compression test, including the crack initiation, crack propagation and final cleavage fracture. The mechanisms of deformation and failure of PBXs under diametric compression were analyzed. The diametric compression test and the techniques developed in this research have proven to be applicable to the study of tensile properties of PBXs. q

Technique for Combined Dynamic Compression–Shear Testing of PBXs

“…PBXs exhibit mechanical properties similar to those of rock, with small failure strains and compressive strengths, which are much higher than tensile strengths [25]. The maximum shear-based failure criterion is widely used to predict the failure of brittle materials [16,25,26]. We assume the failure of the specimens obeying the maximum shear-based failure criterion.…”

Macro-Micro Mechanical Behavior of a Highly-Particle-Filled Composite Using Digital Image Correlation Method

“…The mechanical properties of PBX subjected to a range of conditions are important criteria to determine a safe working life. The study on the mechanical properties and the failure mechanisms of PBX has drawn much attention in recent years [1][2][3][4][5][6][7][8][9]. Low strengths and safety concerns bring additional difficulties in preparing samples and conducting mechanical tests of PBX.…”

Adhesive properties of some fluoropolymer binders with the insensitive explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

“…Bower et al showed that thermomechanical properties such as glass transition temperature (T g ) and extensibility, as well as surface wettability of the binder, are critical for explosive performance and safety [2]. It has been posited that the most common, and limiting, mode of failure in plastic-bonded explosives under thermal or mechanical loads is crack formation and subsequent propagation along explosive crystal-binder interfaces [3][4][5][6]. For example, the mechanical properties of several PBXs were investigated by Palmer et al, revealing that even the most robust material failed by interfacial cracking at tensile stresses as low as 6.8 MPa [6].…”