非线性超声技术检测TATB基PBX微损伤

Detection of Micro-damages in TATB-based Polymer Bonded Explosive by Nonlinear Ultrasonic Technique

针对高聚物粘结炸药(PBX)初始损伤及疲劳损伤问题,利用自行建立的非线性超声测试装置,对模压成型的两种密度三氨基三硝基苯(TATB)基PBX圆柱形试样及其在压缩疲劳过程中的非线性超声参量进行了测试,用断貌分析和计算机断层扫描(CT)验证了非线性超声检测结果。结果表明,与内部初始损伤程度较低的TATB基PBX试样相比,内部存在明显界面损伤的TATB基PBX试样的非线性超声系数明显偏高,非线性超声系数与TATB基PBX初始损伤程度之间有一定的相关性;在TATB基PBX试样疲劳加载至即将产生微裂纹时,非线性超声系数急剧增加并在产生宏观裂纹时达到极值,显示非线性超声参量可监测TATB基PBX疲劳损伤发展过程;TATB基PBX初始损伤程度不同其疲劳损伤速度和发展过程也不尽相同。

Aiming at the problem of initial damage and fatigue damage for polymer bonded explosive(PBX),the nonlinear ultra-sonic parameters of two kinds of triamino trintrobenzene(TATB)-based PBX cylindrical specimens with different density formed by compression molding and these specimens in the process of compressive fatigue were tested by self-established nonlinear ultrasonic testing device.The nonlinear ultrasonic testing results were verified by fracture surface analysis and computer tomography(CT)testing.Compared with TATB-based PBX specimens with less initial interfacial micro-damage degree,the nonlinear ultrasonic co-efficients of the TATB-based PBX specimens with obvious interfacial damage are obviously higher.There is a certain relevance be-tween the nonlinear ultrasonic coefficient and the initial damage degree of TATB-based PBX.When the microscopic crack is nearly generated in the TATB-based PBX,the nonlinear ultrasonic coefficient increases sharply and reaches maximum,revealing that the nonlinear ultrasonic parameters can monitor the fatigue damage developing process.There is a certain difference in fatigue damage rate and developing process for TATB-based PBX specimens with different initial micro-damage degree.