A Research Procedure for Examining the Dynamic Properties of Multi-Wire Springs used in NR-30 Guns

The article presents a concept of the procedure for researching the dynamic properties of the multi-wire springs used in NR-30 guns. The aim of the research was to check the possibilities of determining the limit values of the flexibility of the multi-wire springs for the NR-30 gun, as well as to verify the obtained research results using those from range and static tests (after long compression). While verifying the method (selected measurements of 4 springs with varying degrees of wear), static and dynamic compression tests were performed on a spring mounted on a gun on specially prepared testing stations. The description of the data measurement and acquisition method applied should be considered an important element of the description of a testing station. Based on the obtained research results, it has been inferred that, during the striker’s backward movement, wave phenomena likely transpire in the spring. Force value fluctuations taking place during the spring’s movement are visible in the obtained diagrams. The dynamic and static test results (on springs with varying degrees of wear) allowed the authors to evaluate the impact of a multi-wire spring’s wear on the value of its force of interaction with the automation elements of an NR-30. Based on the data obtained, the assumptions for the method of evaluating multi-wire springs’ durability and using it to evaluate the suitability of a given spring type for use according to its technical state, have been elaborated. The final determination of the limit values of the springs’ parameters requires further research using a station with an ammunition belt encumbrance emulator, as well as emulation of the overloads of the kinematic arrangement of the gun while airborne.