非线性超声技术检测TATB基PBX微损伤

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。

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

Aiming at the problem of initial damage and fatigue damage for polymer bonded explosive (PBX), the nonlinear ultrasonic 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 coefficients of the TATB-based PBX specimens with obvious interfacial damage are obviously higher. There is a certain relevance between 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.