Experimental Investigation of Impact and Friction Sensitivities of AP/Al/HTPB Propellant (19 wt.% Al): A Physical Hardening and Passive Defense Approach for Production Infrastructure
1
Assistant Professor, School of HSE, Imam Hossein Comprehensive University, Tehran, Iran
2
Researcher, School of HSE, Imam Hossein Comprehensive University, Tehran, Iran
Abstract
Building upon a previous study concerning the physical, mechanical, and ballistic properties of an AP/Al/HTPB composite propellant (19 wt% aluminum), the present research focuses on the experimental assessment of its mechanical sensitivity, specifically impact and friction sensitivity. The primary objective is to quantitatively establish the No-Go Limit in accordance with military and industrial safety standards to ensure operational security. This investigation specifically evaluates the influence of formulation parameters, including the R-ratio, curing agent type, and AP particle size distribution, on the sensitivity profiles of high-aluminum-content propellants. Impact test results indicate that this property is predominantly governed by the bulk mechanical properties of the polymer network; reducing the R-ratio significantly enhanced ductility, leading to a 33% reduction in impact sensitivity. Conversely, switching the curing agent from DDI to IPDI resulted in increased sensitivity. Friction sensitivity, however, exhibited a distinct behavior, primarily controlled by the surface chemistry and physical characteristics of the solid particles, where smaller AP particles correlated with higher sensitivity. These findings definitively confirm the lack of direct correlation between impact and friction sensitivities. From a passive defense perspective, the established No-Go Limits (force ranges of 85-95 N and 72-83 N) serve as a critical foundation for risk management protocols aimed at hardening production facilities, securing storage, and mitigating secondary explosions in vital transportation arteries. Such quantitative data facilitate the formulation of rigorous safety standards to reduce the vulnerability of sensitive infrastructure to mechanical stimuli.
Keshvari, A., & taghavi, S. R. (2025). Experimental Investigation of Impact and Friction Sensitivities of AP/Al/HTPB Propellant (19 wt.% Al): A Physical Hardening and Passive Defense Approach for Production Infrastructure. Passive Defense, (), -.
MLA
Abdolrahman Keshvari; seyed reza taghavi. "Experimental Investigation of Impact and Friction Sensitivities of AP/Al/HTPB Propellant (19 wt.% Al): A Physical Hardening and Passive Defense Approach for Production Infrastructure", Passive Defense, , , 2025, -.
HARVARD
Keshvari, A., taghavi, S. R. (2025). 'Experimental Investigation of Impact and Friction Sensitivities of AP/Al/HTPB Propellant (19 wt.% Al): A Physical Hardening and Passive Defense Approach for Production Infrastructure', Passive Defense, (), pp. -.
VANCOUVER
Keshvari, A., taghavi, S. R. Experimental Investigation of Impact and Friction Sensitivities of AP/Al/HTPB Propellant (19 wt.% Al): A Physical Hardening and Passive Defense Approach for Production Infrastructure. Passive Defense, 2025; (): -.
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