Manufacturer-Dependent Variations in Peg–Plate Contact Area and Their Impact on Friction Sensitivity Testing

Abstract. Friction sensitivity testing is essential for evaluating the safety of energetic materials, as it assesses their reactivity to inevitable mechanical stimuli encountered during handling and processing. However, variations in experimental data due to differences in testing conditions remain a major challenge associated with this method. The authors’ previous study investigated the influence of the type of porcelain plates and pegs, which hold the explosive sample and apply friction, on the results of friction sensitivity tests. As a result, the contact area formed between the peg and the plate under an applied load was found to differ among three types of consumables supplied by different manufacturers. This indicates that, even under the same applied load, the pressure acting on the sample varies depending on the consumables. When the surface roughness of the plates is comparable, differences in the contact area, rather than surface roughness, can be regarded as one of the dominant factors causing variations in the friction sensitivity test results. In this study, the factors responsible for the differences in the contact area were investigated by examining the geometries of the peg and plate. In addition, the deformation behavior of the contact surfaces was investigated by observing the surface conditions of the consumables before and after testing.