Evaluation of gun propelling charge performance during the life cycle by statistical utilization of data collected in test and troop gun firings

摘要

The dissertation was intended to improve the quality and safety of gun propelling charges during their life cycle. The approach in three case studies was the evaluation of gun propelling charge performance by the statistical utilization of the results collected in artillery gun test firings and conscript practice troop firings. The interior ballistics branch needs to adjust to the new demands for weapon systems. The literature review shows that the actual interdisciplinary challenges entail the development of new, more energetic but less sensitive and toxic gun propellant compositions, the development of high loading density charge constructions, enhancing the knowledge about the ignition event, research on heat transfer in the gun barrel and barrel wear and further development of mathematical modeling. Primarily due to firing safety it is essential to be able to measure correct pressure values during the ignition and combustion of gun propelling charges in test firings. A discrepancy was detected in the maximum pressure levels measured by using two different pressure measurement methods in the interior ballistic test firings. This problem has been resolved by the development of a new dynamic calibration methodology for the crusher gauge pressure elements. The calibration methodology developed was verified and implemented (Case I). The acceptance control must provide a reliable baseline for the assessment of the performance of gun propelling charges. Quality defects were found in several recently produced 155-mm gun propelling charge lots. The reasons for the poor performance of the procedure for determining gun propelling charge weight were ascertained by applying multivariate analysis methods in new ways to the data set consisting of 155 mm charge weight establishment and uniformity test firing results (Case II). It was found possible to improve the test procedure. The chemical and physical changes occurring during the life cycle of gun propelling charges may impair their safety and performance. It is essential to be aware of such changes as early as possible in the life cycle of the gun propelling charge type. Thanks to new technology, the acquisition of information on ammunition performance is no longer limited to the test firings. The new surveillance system developed and implemented enables the utilization of conscript practice field artillery troop firings for performance data collection of gun propelling charges (Case III).