L-281 Lifing Approaches and Ageing Algorithms
August 2022Kevin Jaansalu (TSO Materials Technology), Matthew Ferran (TSO Munition Systems)
An algorithm describes a process within a system. For lifing algorithms, the system is defined by the national approach to munition life management. From different national approaches, four different lifing systems are proposed and each system is described along with the level of information required for the algorithm to function. Any munition lifing algorithm must take into account different modes of failure of energetic and non-energetic materials, including rupture, fatigue, thermomechanical fatigue, as well as changes in properties and composition due to chemical effects. Many examples from the literature on modelling these different modes are presented.
The aim of these lifing algorithms is to extend munition service life: as more certainty is gained about actual exposure and its effect on material properties, the duration of service of a munition can be increased with confidence. Additional examples demonstrate that effort must also be expended to understand the effects of data precision, uncertainty, and accelerated testing.