Lambros Research Among Fatigue Journal’s Most Downloaded

A paper by Aerospace Engineering at Illinois Prof. John Lambros and his collaborators has been among the International Journal of Fatigue’s 20 most downloaded papers over the past year.

The paper, “High Resolution Digital Image Correlation Measurements of Strain Accumulation in Fatigue Crack Growth,” was the work of Lambros, Mechanical Science and Engineering (MechSE) graduate students Wael Abuzaid and Jay Carroll, and MechSE Prof. Huseyin Sehitoglu.

The work uses a novel ultra-high-resolution digital image correlation technique to measure the plastic strain fields accumulated near a crack tip during fatigue loading (i.e., repeated loading at sub-critical load levels) in a nickel-based superalloy called Hastelloy X.

The paper presents experiments that provided the first sub-grain level, full-field measurements of plastic strain accumulation near a growing fatigue crack. The spatial resolution of these DIC measurements was unprecedented for the large area covered. The strain measurements, which were related to microstructural information obtained through electron backscatter diffraction, shed considerable light on the fatigue crack growth process in polycrystalline metals at the grain level.

The Air Force Research Laboratory funded the work, which was part of the Midwest Structure Science Center operating at Illinois from 2006 to 2013.