Effect of Pre‐Strain Aging on the Microdamage Properties of Composite Solid Propellant

Abstract

Accelerated aging tests under pre‐strain were conducted on HTPB‐based composite solid propellant with the goal of investigating the effect of pre‐strain aging on its microdamage properties. The tensile fracture morphologies, stress‐strain curve and dissipative energy density of propellant samples were analyzed. Results showed that there was no obvious dewetting macroscopically when the pre‐strain was less than 9 %, but the pre‐strain can still cause microdamage of propellant interface. The microdamage of propellant interface can be characterized by the critical dewetting strain, corresponded to pre‐strain by a linear law. The bonding performance between HTPB propellant matrix and solid filler was mainly affected by aging temperature. There was a critical temperature TC, For the HTPB propellant investigated in this study, the TC is between 65 °C and 70 °C. When aging temperature is below TC, there was no significant decrease in the overall levels of dissipated energy density, but decrease began significantly when the aging temperature is above TC.

Analysis of thermomechanical coupled accelerated aging of HTPB propellants

“…HTPB propellants, distinguished by their stable mechanical properties and high energy efficiency, are extensively employed in contemporary high-performance solid rocket engines [4,[37][38][39][40][41][42]. As previously noted, the influence of external mechanical stresses on the aging behavior of HTPB propellants in such applications is significant.…”

“…For instance, Wang [37] examined the mechanical properties of HTPB propellants under varying aging durations and pre-strain conditions, subsequently developing a comprehensive stressstrain behavior model. Additionally, Zhou [38] discovered that the micro-damage characteristics of HTPB propellants under different pre-strain conditions are intricately linked to the aging temperature. These studies lay a crucial scientific groundwork for comprehending the aging behavior of HTPB propellants in complex environments subjected to external mechanical stresses.…”