We study the indentation of a free-standing lipid membrane suspended over a nanopore on a hydrophobic substrate by means of molecular dynamics simulations. We find that in the course of indentation the membrane bends at the point of contact and the fringes of the membrane glide downward intermittently along the pore edges and stop gliding when the fringes reach the edge bottoms. The bending con...

An approximate two-dimensional model for indentation of blunt objects into various types of rigid-perfectly plastic cohesive-frictional material is derived. Particular emphasis is placed on considering indentation as a process involving evolution of the boundary of material displaced by the indenter. Force-penetration relationships are obtained by an incremental approach utilizing key kinematic...

Novel techniques for characterizing and assessing the properties of Ni-base superalloys are becoming increasingly important to the accelerated development of new structural alloys and the advancement of physics-based mechanical property models. Instrumented indentation techniques have long served as a useful approach for probing the mechanical response of a wide range of engineering materials. ...

PURPOSE To evaluate the lens edge interaction with the ocular surface with different edge designs using optical coherence tomography and to examine the effect of lens power on the lens edge interactions. METHODS Four types of silicone hydrogel lenses with different edge designs (round-, semi-round-, chisel-, and knife-edged) at six different powers (+5.0, +3.0, +1.0, -1.0, -3.0, and -5.0 diop...

Indentation techniques for assessing fracture toughness are attractive due to the simplicity and expediency of experiments, and because they potentially allow the characterization of both local and bulk fracture properties. Unfortunately, rarely have such techniques been proven to give accurate fracture toughness values. This is a concern, as such techniques are seeing increasing usage in the s...

Foreign object damage (FOD) occurs when hard, millimeter-sized objects such as gravel or sand and even the pieces of the engine components are ingested into aircraft jet engines. Particles impacting blades produce small indentation craters which can become sites for fatigue crack initiation, severely limiting the lifetime of the blade. In this study, the impact on the edge of a thin plate is in...

The atomic force microscope (AFM) has found wide applicability as a nanoindentation tool to measure local elastic properties of soft materials. An automated approach to the processing of AFM indentation data, namely, the extraction of Young's modulus, is essential to realizing the high-throughput potential of the instrument as an elasticity probe for typical soft materials that exhibit inhomoge...

BACKGROUND AND OBJECTIVES Mechanical indentation has been shown to increase light transmission through turbid tissue. In this study, we investigated the effects of localized indentation on the optical properties of ex vivo porcine skin specimens by dynamically monitoring diffuse reflectance spectra, light transmission, and applied load while controlling tissue thickness. STUDY DESIGN/METHODS ...

A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse nite element analysis This item was submitted to Loughborough University's Institutional Repository by the/an author. A hybrid approach to determining cornea mechanical properties in vivo using a combination of nano-indentation and inverse nite element analysis. A hybrid app...

Indentation creep tests were performed on an Al-5.3mol% Mg solid-solution alloy to examine whether mechanical properties can be extracted accurately from a testpiece, as small as a rice grain. A conical diamond indenter was pressed into a test surface with a constant load F at temperatures ranging from 0.60 to 0.65 Tm (Tm: the absolute liquidus temperature). When the representative flow stress ...