Effects of surface stress on the indentation response of an elastic half-space

Zhou, Wenxiao; Yang, Fuqian

doi:10.1016/j.ijmecsci.2022.107512

Cited by 11 publications

(1 citation statement)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our case, the rounded corners at the base of the indenters did not interfere with the test of hypothesis "2" of Section 2, since the rounding only affected the results obtained at the beginning of the indentation process. Moreover, the use of rounded corners at the top of the conical punches avoided the occurrence of a region with a singular stress concentration [60,61], which can lead to the destruction of the elastomer surface [62], especially at a tangential indenter shift.…”

Section: Conical Profilesmentioning

confidence: 99%

Controlling the Friction Coefficient and Adhesive Properties of a Contact by Varying the Indenter Geometry

Lyashenko,

Pham,

Popov

2024

Processes

View full text Add to dashboard Cite

In the present paper, we describe a series of laboratory experiments on the friction between rigid indenters with different geometrical forms and an elastic sheet of elastomer as a function of the normal load. We show that the law of friction can be controlled by the shape of the surface profile. Since the formulation of the adhesive theory of friction by Bowden and Tabor, it is widely accepted and confirmed by experimental evidence that the friction force is roughly proportional to the real contact area. This means that producing surfaces with a desired dependence of the real contact area on the normal force will allow to “design the law of friction”. However, the real contact area in question is that during sliding and differs from that at the pure normal contact. Our experimental studies show that for indenters having a power law profile f(r) = cnrn with an index n < 1, the system exhibits a constant friction coefficient, which, however, is different for different values of n. This opens possibilities for creating surfaces with a predefined coefficient of friction.

show abstract

Section: Conical Profilesmentioning

confidence: 99%

Controlling the Friction Coefficient and Adhesive Properties of a Contact by Varying the Indenter Geometry

Lyashenko,

Pham,

Popov

2024

Processes

View full text Add to dashboard Cite

show abstract

Flexoelectricity Modulated Electron Transport of 2D Indium Oxide

Hu,

Yu Chen,

Luan

et al. 2024

Advanced Science

View full text Add to dashboard Cite

The phenomenon of flexoelectricity, wherein mechanical deformation induces alterations in the electron configuration of metal oxides, has emerged as a promising avenue for regulating electron transport. Leveraging this mechanism, stress sensing can be optimized through precise modulation of electron transport. In this study, the electron transport in 2D ultra‐smooth In2O3 crystals is modulated via flexoelectricity. By subjecting cubic In2O3 (c‐In2O3) crystals to significant strain gradients using an atomic force microscope (AFM) tip, the crystal symmetry is broken, resulting in the separation of positive and negative charge centers. Upon applying nano‐scale stress up to 100 nN, the output voltage and power values reach their maximum, e.g. 2.2 mV and 0.2 pW, respectively. The flexoelectric coefficient and flexocoupling coefficient of c‐In2O3 are determined as ≈0.49 nC m−1 and 0.4 V, respectively. More importantly, the sensitivity of the nano‐stress sensor upon c‐In2O3 flexoelectric effect reaches 20 nN, which is four to six orders smaller than that fabricated with other low dimensional materials based on the piezoresistive, capacitive, and piezoelectric effect. Such a deformation‐induced polarization modulates the band structure of c‐In2O3, significantly reducing the Schottky barrier height (SBH), thereby regulating its electron transport. This finding highlights the potential of flexoelectricity in enabling high‐performance nano‐stress sensing through precise control of electron transport.

show abstract

A review of inverse problems for generalized elastic media: formulations, experiments, synthesis

Fedele,

Placidi,

Fabbrocino

2024

Continuum Mech. Thermodyn.

View full text Add to dashboard Cite

Starting from the seminal works of Toupin, Mindlin and Germain, a wide class of generalized elastic models have been proposed via the principle of virtual work, by postulating expressions of the elastic energy enriched by additional kinematic descriptors or by higher gradients of the placement. More recently, such models have been adopted to describe phenomena which are not consistent with the Cauchy-Born continuum, namely the size dependence of apparent elastic moduli observed for micro and nano-objects, wave dispersion, optical modes and band gaps in the dynamics of heterogeneous media. For those structures the mechanical response is affected by surface effects which are predominant with respect to the bulk, and the scale of the external actions interferes with the characteristic size of the heterogeneities. Generalized continua are very often referred to as media with microstructure although a rigorous deduction is lacking between the specific microstructural features and the constitutive equations. While in the forward modelling predictions of the observations are provided, the actual observations at multiple scales can be used inversely to integrate some lack of information about the model. In this review paper, generalized continua are investigated from the standpoint of inverse problems, focusing onto three topics, tightly connected and located at the border between multiscale modelling and the experimental assessment, namely: (i) parameter identification of generalized elastic models, including asymptotic methods and homogenization strategies; (ii) design of non-conventional tests, possibly integrated with full field measurements and advanced modelling; (iii) the synthesis of meta-materials, namely the identification of the microstructures which fit a target behaviour at the macroscale. The scientific literature on generalized elastic media, with the focus on the higher gradient models, is fathomed in search of questions and methods which are typical of inverse problems theory and issues related to parameter estimation, providing hints and perspectives for future research.

show abstract

Effects of surface stress on the indentation response of an elastic half-space

Cited by 11 publications

References 74 publications

Controlling the Friction Coefficient and Adhesive Properties of a Contact by Varying the Indenter Geometry

Controlling the Friction Coefficient and Adhesive Properties of a Contact by Varying the Indenter Geometry

Flexoelectricity Modulated Electron Transport of 2D Indium Oxide

A review of inverse problems for generalized elastic media: formulations, experiments, synthesis

Contact Info

Product

Resources

About