The uniaxial deformation of polycrystals are modelled using three incremental rate-insensitive micro-mechanic models; the Taylor model, the Sachs model and Hutchinson’s self-consistent model. The predictions of the two rigid plastic upperand lower-bound models (Taylor and Sachs) are compared with the predictions of the elastic-plastic self-consistent model. As expected, the results of the self-...

A new technique for measuring the elastic-plastic properties of porous thin films by means of nanoindentation is proposed. The effects of porosity on indentation hardness and modulus are investigated through finite element analyses based on the Gurson model for plastic deformation of ductile porous materials. Intrinsic mechanical properties of the thin film are obtained by eliminating both subs...

TiAlN/Al2O3 multilayers with different Ar/N2 ratios were deposited on Si substrates in different N2 partial pressure by magnetron sputtering. The crystalline and multilayer structures of the multilayers were determined by a glancing angle X-ray diffractometer (XRD). A nanoindenter was used to evaluate the hardness, the elastic modulus and scratch scan of the multilayers. The chemical bonding wa...

A combined scanning force and tunneling microscope is used to study the plastic deformation of a connective neck of nanometer dimensions formed by cohesive bonding between metal tip and substrate after contact. The applied force and conductance of the neck are measured simultaneously during the deformation process, which proceeds in alternating elastic and yielding stages. From these data the Y...

In the study we experimentally examine the influence of elastic properties and surface morphology on the inter-particle friction of natural soil grains. The experiments are conducted with a custom-built micromechanical apparatus and the database is enhanced by testing engineered-reference grains. Naturally-occurring geological materials are characterized by a wide spectrum of mechanical propert...

attempts have been made for the first time to produce a friction material with thermal sensitive modulus by the inclusion of combined plastic/rubber properties of thermoplastic elastomers (tpe) as viscoelastic polymeric materials into the formulation for the purpose of increasing the damping behavior. in order to evaluate the viscoelastic parameters such as loss factor (tan δ) and elastic modul...

Objective(s): One of the main constraints of collagen hydrogel scaffolds for using in tissue engineering is mechanical weakness. Plastic compression (PC) is a physical method to overcome the mechanical limitation of collagen hydrogel. Materials and Methods: In this study, the effects of pH on mechanical and biological properties of PC hydrogels were investigated. Collagen hydrogels were fabrica...

The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transit...

PURPOSE Preservative treatments are necessary for disinfection and long term storage when dealing with biological tissue. Freezing is a gold standard but infectious risk can only be eliminated by using chemical fluids that may alter the mechanical properties, depending on their composition. Therefore, we experimentally evaluated the influence of freezing and of two commonly used preservative fl...

To enhance preventative and therapeutic strategies for metabolic bone diseases and bone fragility disorders, we began to explore the physical properties of bone tissue at the cellular level. Proximal femurs were harvested from 27 cadavera (16 male and 11 female) for in vitro measurement of the mechanical properties. We measured the variations in lamellar-level elastic modulus and hardness in hu...