ÐA general theory is presented for the axisymmetric indentation of piezoelectric solids within the context of fully coupled, transversely isotropic elasticity models. Explicit expressions for P±h curves are derived for spherical, conical as well as cylindrical punch indenter geometries in a manner that can be directly related to the experimental measurements. In addition, results for di€erent e...

It is well known that several ceramic materials develop an usual; and sometimes unique; combination of properties as a result of mixing different phases with similar expansion coefficients. Sometimes they are elastically stiff, have relatively low thermal expansion coefficients, good thermal and electrical conductivities, and are resistant to chemical attack. As this paper will show, their mech...

We present an approach for motion estimation from videos captured by depth-sensing cameras. Our method uses the technique of graph matching to find groups of pixels that move to the same direction in subsequent frames. In order to choose the best matching for each patch, we minimize a cost function that accounts for distances on RGB and XYZ spaces. Our application runs at real-time rates for lo...

The indentation process of pressing a Rockwell diamond indenter into inelastic material has been studied to provide a means for the analysis, simulation and prediction of Rockwell hardness tests. The geometrical characteristics of the spheroconical-shaped Rockwell indenter are discussed and fit to a general function in a self-similar way. The complicated moving boundary problem in Rockwell hard...

The study of indentation responses of rate-dependent (viscoplastic or creeping) solids has generally focused on the relationship between indentation hardness and an effective strain rate, which can be defined from a similarity transformation of the governing equations. The strain rate sensitivity exponent can be determined from the slope of a log-log plot of the hardness versus effective strain...

Instrumented indentation methods, which provide a continuous record of the variation of indentation load, P, as a function of the depth of penetration, h, into the indented specimen, have been the topics of considerable attention in recent years. Such interest can be attributed to the following possible applications of the methods. (1) Properties such as Young’s modulus, yield strength, and str...

To measure the hardness of a material, an indenter is pressed into the material and the deformation is measured. As we focus on Vickers hardness testing, our exercise is to compute the diagonal lengths of a square indentation. We especially investigate if it is possible to reconstruct the shape of the indentation by the use of the Shape-from-Focus method. We show that the shape information alon...

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...

We describe a technique using deep anterior lamellar keratoplasty (DALK) in 5 eyes that developed keratectasia after LASIK. The technique is based on surgical manipulation that allows visualization of the lamellar dissection depth using a posterior approach to reach the predescemetic space. The mirror effect, indentation effect, and folding effect were used to determine proximity to Descemet's ...

The nanoscale anisotropic elastic-plastic behavior of single-crystal aragonite is studied using nanoindentation and tapping mode atomic force microscopy imaging. Force-depth curves coaxial to the axis exhibited load plateaus indicative of dislocation nucleation events. Plasticity on distinct slip systems was evident in residual topographic impressions where four pileup lobes were present after ...