A Nonlinear Ultrasonic Method for Detection and Characterization of Dewetting Damage in Solid Propellant
A Nonlinear Ultrasonic Method for Detection and Characterization of Dewetting Damage in Solid Propellant
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DOI：
10.1002/prep.202200079
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发表时间：
2022-07-20
影响因子：
1.8
通讯作者：
Chu, Xi-Hua
中科院分区：
文献类型：
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作者：
Pan, Yu;Qu, Wen-Zhong;Chu, Xi-Hua
固体推进剂在载荷作用下的脱湿损伤是影响固体推进剂本构性能的关键因素，它会削弱固体火箭发动机装药的结构完整性。其演化过程的定量表征一直是一个非常活跃的研究领域。本文提出了一种非线性超声（NLU）方法来实时研究和监测固体推进剂的非线性动态响应。将表征脱湿损伤的NLU参数用频率峰值、传播距离等物理量表示，并在不同应变下对圆棒固体推进剂试件进行拉伸试验。定义了初始去湿点、特征去湿点和特征去湿速率来表征去湿性能。结果表明，随着拉伸过程的发展，非线性非线性参数不断变化，在初始脱湿损伤点处，非线性参数急剧增加。通过对实验数据的分析，提出了表征非线性单元参数随应变变化规律的经验公式，该公式能很好地拟合不同应变率下的实验数据。此外，还进行了相关的数值仿真，仿真结果验证了该方法的可行性。
The dewetting damage of solid propellant under loading is a key factor affecting the constitutive properties of solid propellant, and it will weaken structural integrity of solid rocket motor charge. The quantitative characterization of its evolution process has always been a very active research field. In this study, a nonlinear ultrasonic (NLU) method is proposed to investigate and monitor in real-time the nonlinear dynamic response of solid propellant. The NLU parameter, which can evolve dewetting damage, is expressed by some physical quantities such as the frequency peak, the propagation distance and so on, and is recorded at different strain in the tensile tests of the round rod solid propellant specimens. Then, the initial dewetting point, characteristic dewetting point and characteristic dewetting rate are defined to characterize the dewetting performance. The results show that NLU parameter changes continuously with the evolution of tensile process and increases sharply at the initial dewetting damage point. By analyzing the data, an empirical formula characterizing the variation law of NLU parameter with strain is proposed, which is well fitted to the experimental data under different strain rates. In addition, relevant numerical simulation is carried out, and the simulation results verify the feasibility of the NLU method.