Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the sti...

in this paper, a general elastoplastic-damage constitutive model considering the effect of strain rate has been developed. the derivation of this model has been cast into the irreversible thermodynamics with internal variables within the fundamentals of continuum damage mechanics (cdm). the rate effect has been involved as an additional term into the plastic yield surface (dynamic plastic yield...

This paper presents the effect of geogrid tensile strength by calculating pullout resistance and geogrid-soil interaction mechanism. In order to investigate this interface, a series of pullout tests have been conducted by large scale reformed direct shear test apparatus in both cohesive and granular soils. In numerical, finite difference software FLAC3D has been carried out on experimental test...

this paper is concerned with the surface and small scale effects on transverse vibration of a viscoelastic single-layered graphene sheet (slgs) subjected to an in-plane magnetic field. the slgs is surrounded by an elastic medium which is simulated as visco-pasternak foundation. in order to investigate the small scale effects, the nonlocal elasticity theory is employed due to its simplicity and ...

In this study, a semi analytical method for transverse and axial vibration of single-walled boron nitride nanotube (SWBNNT) under moving a nanoparticle is presented. The surrounding elastic medium as Pasternak foundation and surface stress effect are included in the formulations of the proposed model. Using Timoshenko beam theory (TBT), Hamilton’s principle and nonlocal piezoelasticity theory, ...

The previously derived expressions for the incremental elastic coefficients of an isotropic medium under initial stress are applied to rubbertype elasticity. As a corollary an exact theory is obtained for the surface instability of such material under compression. It is found that in plane strain the incremental properties remain isotropic and are characterized by a single strain-dependent modu...

This paper investigates experimentally the effect of compressed cold air (CCA) and vegetable oil on the surface integrity and residual tresses of ground tool steel components. It shows that CCA can reduce grinding temperature and produce a compressive residual stress up o the grinding depth of 30 m. CCA can also improve surface finish while keeping grinding forces low. Oil was found to be more ...

The shrinkage mechanisms of portland cement paste were investigated from shrinkage, weight loss, and pore structure measurements using nitrogen sorption and mercury intrusion porosimetry (MIP). Thin samples (2.3 mm) of well-hydrated (165 d) pastes of 0.4 and 0.6 water-to-cement (W/C) ratios were dried directly from saturated surface dry state to 75%, SO%, 11%, and 0% relative humidity (rh). Fro...

A stressed epitaxial film can undergo surface instability. The stress field and the interface interaction have profound effects on the dynamics of surface evolution that leads to selfassembled quantum dots. In this paper, by using a nonlinear evolution equation, we investigate pattern evolution of self-assembled quantum dots under general biaxial stresses. It is found that the shape of quantum ...