A Nonlinear Ultrasonic Method for Detection and Characterization of Dewetting Damage in Solid Propellant

Abstract

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.

Prediction of Aging Performance of Particle-Filled Polymer Composites Based on RVE Model

“…With the increase in strain, nonlinearity appears due to the debonding of the particles and matrix. The point at which the slope experiences the maximum change is defined as a dewetting point [ 27 , 28 , 29 ]. The third stage is the matrix-bearing stage, during which the interface fails and the matrix bears the load.…”

A coda wave interferometry to characterize and evaluate the powder debonding damage of solid propellant: Experimental investigation and discrete element simulation

“…In order to achieve good ballistic performance, CSP needs to be filled with high volume fraction of solid powder, and its structural integrity needs to be maintained during storage conditions and ignition process after storage. The interface between solid filled powder and binder matrix is usually the weak link of propellant structural integrity, and its interface strength largely determines the mechanical properties of solid propellant (Lei et al., 2020; Pan et al., 2022). Under the action of external load, the solid powder will be debonded and separated from the surrounding matrix, which is the main form of damage for solid propellant (Ma et al., 2019; Zhi et al., 2012).…”