Research On The Nonlinear Ultrasonic Response Of Polymer Bonded Explosive Damage

Polymer bonded explosive(PBX)was a kind of heterogeneous poly phase composite material with highly packed explosive crystals,which would produce all kinds of initial damage inevitably during the manufacture process.The initial micro-interface damages of PBX parts would expand with heating and mechanical force,which would affect the usage-efficiency,detonation-safety and storage-reliability.The nonlinear ultrasonic testing device for study was established.The nonlinear ultrasonic testing technique for fatigue and creep damage of TATB-based PBX components was researched on.The nonlinear ultrasonic response behavior in fatigue and creep of PBX components was obtained.The experimental investigation showed that the nonlinear ultrasonic parameter responded evidently on the fatigue and creep evolution but the linear ultrasonic parameter such as gain and velocity didn't have evident response on it.The feasibility of monitoring the fatigue and creep damage of PBX by nonlinear ultrasonic was proved experimentally,which found a base to engineering applications such as damage identification,performance regression monitoring and lifetime prediction of the explosive parts.An experiment on the thermal shock damage of HMX-based PBX,TATB-based PBX and HMX+TATB-based PBX cylinder with different density and their evolution course in water under different temperature gradient(from ±10? to ±20?,±30?,±40?)by using nonlinear ultrasonic testing device.The nonlinear ultrasonic response behavior for thermal shock damage of HMX-based PBX,TATB-based PBX and HMX+TATB-based PBX cylinder specimen was obtained.The experimental investigation showed that the nonlinear ultrasonic parameter responded evidently on the thermal shock damage evolution,especially for HMX-based PBX.An experiment on the fatigue compression loading of TATB-based PBX cylinder and the damage evolution course by using nonlinear ultrasonic testing device.The nonlinear ultrasonic response behavior for fatigue damage,modulus of elasticity and their variation of TATB-based PBX cylinder specimen was obtained.The experimental investigation showed that the nonlinear ultrasonic parameter responded evidently on the fatigue damage evolution.Especially during the micro process of crack initiation,the nonlinear ultrasonic parameter changed by orders of magnitude,while modulus of elasticity changes no for than 15%.The research would offer technological support for evaluate fatigue damage,creep damage and thermal shock damage and deterioration of mechanical properties of PBX in storage.