Performance Modeling of a Pyrotechnically Actuated Pin Puller

Abstract

An analytical model was developed to understand the physics and predict the functional performance of a pin puller. The formulated model is based on one-dimensional gas dynamics for an ideal gas. Resistive forces against pin shaft movement were measured in quasi-static mechanical tests, the results of which were incorporated into the model. The expansion chamber pressure and the pin shaft displacement were measured from an actual firing test and compared to the model prediction. The gas generation rate was adjusted by a correction factor, and the heat transfer rate was obtained through parametric analysis. The validity of the model is assessed for additional firing tests with different amounts of pyrotechnic charge. This model can provide knowledge on how the pin puller functions, and on which design parameters contribute the most to the actuation of the pin puller. Using this model, we estimate the functional safety factor by comparing the energy generated by the pyrotechnic charge to the energy required to accomplish the function.

Performance Optimization of a Split-Type Low-Shock Separation Bolt

“…The heat loss rate is empirically assumed to be 120 J∕s [4]. In a very small initial volume, the energy efficiency, η p , can be varied due to incomplete combustion and interaction with the inner surface of the chamber.…”

“…Therefore, it would be very useful to predict the separation behaviors and performance by a mathematical model. A few researchers have studied mathematical models of devices using a pressure cartridge especially for the pin puller [2][3][4][5] and the pyrotechnic valve [6,7], which are based on simple piston mechanism. However, only a few analytical studies on the separation behavior of lowshock separation bolts with a complex mechanism have been reported.…”

Concept of Unburning Ratio and Combustion Modeling of ZPP and BKNO3 in Pyroshock‐Reduced Separation Nut

“…To simulate pyrotechnic mechanical devices that are actuated by pressure, many studies have been done to model the combustion of single explosive charge such as cyclotetramethylene tetranitramine (HMX) [3][4][5][6], and zirconium potassium perchlorate (ZPP) [7][8][9][10][11][12][13]. However, for many pyrotechnics, ZPP is used as the initiating explosive and boron potassium nitrate (BKNO 3 ) is used as the main charge explosive.…”

Functional Reliability Estimation of Pin Pullers Based on a Probit Model

“…. Jang et al [2] 과 Lee et al [3] 은 핀풀러의 작동을 6 개의 상미분 방정식을 통하여 성능 모델링(performance modeling)하였으며, 특히 Lee et al [3] 은 Kort et al …”