Damage Progression in Fuze Assemblies Subjected to High-G Mechanical Shock Using X-Ray Digital Volume Correlation

Field extracted electrical assemblies, subjected to harsh environments including storage, and transportation may have often sustained degradation in their material properties and physical structure, without exhibiting external signs of damage. The lack of macro-indicators of damage makes the quantification of sustained damage and the remaining useful life challenging for assessment of the reliability makes quantification of accrued damage and remaining useful life much difficult. The operation environment requires survivability under high-g loads often in excess of 10,000g-100,000g. The need of non-destructive test methods for determination of the internal damage and the assessment of expected operational reliability under the presence of accrued damage from prolonged storage is extremely desirable. While a number of non-destructive test methods such as x-ray, and acoustic imaging exist in the state-of-art — they are limited to the acquisition of imaging of the internal damage state without the ability of conducting measurement of deformation under the action of environment loads. There is scarcity of literature on studying progressive damage to the physical structure of fuze components when subjected to high g shocks. Previously, researchers have studied the reliability of fuze subjected to high-temperature and high-g mechanical shocks, measured redundancy and reliability of fuze electronics through prediction of failure rates and MTTF using MIL-HDBK-217F standard, and performed on fault diagnosis. In this paper, a full-field deformation measurement technique has been presented to monitor damage in key components of the fuze after exposure to multiple high G shocks. Fuze assembly has been subjected to 30,000g mechanical shock until failure. The fuze assembly is CT scanned at regular intervals and the scan data is compared to the pristine scan data to compute physical deformations and damage sustained during the mechanical shock event.