OBJECTIVES/METHODS From a materials scientist's perspective, dental materials used for tooth repair should exhibit compatible mechanical properties. Fulfillment of this criterion is complicated by the fact that teeth have a hierarchical structure with changing mechanical behavior at different length scales. In this study, nanoindentation with an 8 microm spherical indenter was used to determine...

In this article, we present a quantitative stiffness imaging technique and demonstrate its use to directly map the dynamic mechanical properties of materials with nanometer-scale lateral resolution. For the experiments, we use a ‘‘hybrid’’ nanoindenter, coupling depth-sensing nanoindentation with scanning probe imaging capabilities. Force modulation electronics have been added, enhancing instru...

The introduction of certain controlled gradients in plastic properties is known to promote resistance to the onset of damage at contact surfaces during some tribological applications. Gradients in composition, microstructure and plastic properties can also be deleterious to contact-damage resistance in some situations. In order to realize such potentially beneficial or deleterious effects of pl...

The mechanics governing the lateral cracks that form when a hard object plastically penetrates a ceramic is presented. The roles of indentation load, penetration depth, and work of indentation are all highlighted, as are the influences of the mechanical properties of the material. A closed form solution for cracking induced by expansion of a two-dimensional cavity is used to bring out essential...

A methodology for interpreting instrumented sharp indentation with dual sharp indenters with different tip apex angles is presented by recourse to computational modeling within the context of finite element analysis. The forward problem predicts an indentation response from a given set of elasto-plastic properties, whereas the reverse analysis seeks to extract elasto-plastic properties from dep...

This paper describes a method for evaluating material properties of multi-layered system and functional gradient materials from data obtained from indentation testing. The measurement data collected from the penetration force-depth curves is employed for identifying elastic moduli of thin films and functional gradient materials. An axisymmetric indentation problem is first analyzed on the basis...

The atomic force microscopy (AFM) has been widely used to measure the mechanical properties of biological cells through indentations. In most of existing studies, the cell is supposed to be linear elastic within the small strain regime when analyzing the AFM indentation data. However, in experimental situations, the roles of large deformation and surface tension of cells should be taken into co...

Results are reported from two molecular-dynamics simulations designed to yield insight into the engineering of nanometre-scale structures. The first is the initial stages of the indentation of a silicon substrate by an atomically-sharp diamond tip. Up to an indentation depth of approximately 0.6 nm the substrate responds elastically and the profile of the disturbed region of the substrate norma...

The main goal of this work is to determine values of elastic constants of orthotropic, transversely isotropic and cubic materials through indentation tests on thin layers bonded to rigid substrates. Accordingly, we first use the Stroh formalism to provide an analytical solution for generalized plane strain deformations of a linear elastic anisotropic layer bonded to a rigid substrate, and inden...

Over the past decade, many computational studies have explored the mechanics of normal indentation. Quantitative relationships have been well established between the load–displacement hysteresis response and material properties. By contrast, very few studies have investigated broad quantitative aspects of the effects of material properties, especially plastic deformation characteristics, on the...