Experimental Study on Rate-Dependent Constitutive Relations with Damage for Plastic-Bonded Explosives

Cyclic loading and unloading experiments and the uniaxial compressive experiment of plastic-bonded explosives (PBX) under different strain rate were performed by a universal material testing machine. The stress-strain curves of plastic-bonded explosives were obtained in different operating conditions. Based on the idea of combining phenomenological analysis and micro-statistical analysis, a damage evolution equation with damage internal variable and rate-dependent constitutive relations with damage for plastic-bonded explosives were given. The model was checked with the experimental data, and the relevant parameters of rate-dependent constitutive relations with damage were obtained. Experimental results indicate that the constitutive equation can describe mechanical properties of the PBX explosives at the linear elastic stage, strengthen stage, and strain softening stage. The constitutive relation is simple and requires less parameters to be determined. The damage variable defined by micro-crack density can be easily determined by mechanical testing.