Determination of JWL Equation of State Parameters of Explosives Using Cylinder Expansion Test

Several types of equations are used for modeling the relationship among the state parameters of explosives and computer implementation is mostly needed for predicting the behavior of explosives. During modeling of detonation characteristics of explosives in simulations, Jones-Wilkins-Lee (JWL) equation of state (EOS) is widely used. The parameters of JWL EOS are not always available for newly developed explosive compositions. In this study, cylinder expansion test has been utilized to determine parameters. Cylinder expansion tests have been performed for different Polymer Bonded Explosives (PBX) and TNT with the designed setup and JWL EOS parameters are obtained. Gurney constants are also derived by post-processing the test results. Pressure - specific volume ratio curves for these explosives are compared with the curves available in literature and seen that the results are close for similar compositions. Parameters are also verified with the comparison of open area blast measurement results with numerical simulation.