Kurt E. Johanns

TL;DR: In this paper, a simple stochastic model is developed to determine the pop-in load and maximum shear stress at popin in nanoindentation experiments conducted with spherical indenters that accounts for recent experimental observations of a dependence of these parameters on the indenter radius.

TL;DR: In this paper, an aberration corrected scanning transmission electron microscope was used to study the defect structures in as-grown and pre-strained single crystal Mo alloy fibers, which were found to be defect free over large lengths while the highly prestrained (16%) fibers had high defect densities that were uniform throughout.

TL;DR: In this paper, the authors focus on the potential sources of experimental error in the context of nanoindentation experiments performed in the time and frequency domains and draw attention to these potential sources to motivate experimental verification in a manner that will enhance accuracy and enable future breakthroughs in the application of nanoinventation to viscoelastic solids.

TL;DR: In this paper, a cohesive zone model is applied to a finite element (FE) scheme to simulate indentation cracking in brittle materials, and the authors show that the principles of linear-elastic fracture mechanics can be applied when indentation cracks are long in comparison to the size of the cohesive zone.

TL;DR: In this paper, as-grown and pre-strained single-crystal molybdenum-alloy fibers were tested in tension and compression conditions, and a wide scatter of yield strengths between 1 and 10 GPa was observed.