Multimodal nondestructive evaluation of internal surfaces of holes in steel structures

The innovation is fusion of data from optical and magnetic methods using novel model-based tools. The focus is high resolution defect imaging in the presence of corrosion/pitting for gun barrel evacuator holes and bores. Phase I demonstrated feasibility on simulated pits with notches and gun barrels with rifling. Phase II will mature data fusion algorithms, taking advantage of high resolution optical imaging capabilities and reliable eddy current crack detection. A handheld, light-weight practical solution will be demonstrated in Phase II. A critical challenge is the reality that optical methods cannot detect tight cracks, although they can provide high resolution imaging of open cracks. This is especially true in the presence of corrosion products and surface contamination. It is essential to include a reliable crack detection method, such as the JENTEK MWM-Array, which is uniquely capable of detecting tight surface and sub-surface cracks. In addition, the MWM-Array feasibility to map surface pitting was demonstrated in Phase I. Geometric registration of the magnetic and optical images enables rescaling and correction of crack detection data in the presence of pits and general corrosion. Together, fusion of magnetic and optical data will substantially enhance the Army’s capability to maintain and sustain gun barrel assets.