Isogeometric thermal postbuckling analysis of porous FGM quasi-3D nanoplates having cutouts with different shapes based upon surface stress elasticity

With the aid of the non-uniform rational B-spline (NURBS)-based isogeometric technique, for the first time, the size-dependent geometrically nonlinear bending characteristics of microplates made of porous functionally graded materials (FGMs) having a central cutout with different shapes are studied The nonlocal strain gradient continuum elasticity within the framework a hybrid higher-order quasi-3D plate theory is adopted to describe the kinematic relations via only four unknowns To capture the effective material properties, a porosity-dependent rule of mixture is employed The nonlocal strain gradient nonlinear load–deflection responses are obtained corresponding to various geometrical and material parameters as well as different boundary conditions It is revealed that the significance of both the nonlocal and strain gradient reduces This prediction is the same for all values of the material property gradient index as well as the porosity index Also, it is demonstrated that a central cutout leads to change the trend of load–deflection response, and this change occurs at a specific value for the applied distributed load which depends on several parameters such as the cutout geometry and boundary conditions In addition, it is displayed that corresponding to different maximum deflections, the significance of the strain gradient size effect in the absence of nonlocality on the nonlinear flexural stiffness of a porous FGM microplate is more than that of the nonlocal size effect in the absence of the strain gradient size dependency

Size-dependent nonlinear bending behavior of porous FGM quasi-3D microplates with a central cutout based on nonlocal strain gradient isogeometric finite element modelling

In the present study, through matching the moving Kriging meshfree formulations with the third-order shear flexible shell model together with the modified strain gradient continuum mechanics, the microstructural-dependent nonlinear stability behavior of micropanels under axial compression is explored. The micropanels are made of composites containing graphene nanoplatelets dispersed in random checkerboard pattern. The associated material characteristics are evaluated via a probabilistic-based homogenization scheme. Afterward, proper meshfree functions are implemented to enforce the essential boundary conditions at the considered nodding system accurately. It is highlighted that the stiffening characters of the microstructural gradient tensors cause to rise the critical stability load as well as the critical shortening of composite micropanels. Also, these stiffening characters make an enhancement in the minimum snap-through postbuckling compression, and shift it to lower values of the panel deflection and end shortening. Additionally, it is demonstrated that among different microstructural gradient tensors, the stiffening character of rotation gradient is more than deviatoric stretch gradient, the stiffening character of the later is more significant than the dilatation gradient tensor.

Microstructural-dependent nonlinear stability analysis of random checkerboard reinforced composite micropanels via moving Kriging meshfree approach

Isogeometric nonlinear bending analysis of porous FG composite microplates with a central cutout modeled by the couple stress continuum quasi-3D plate theory

This study presents the size-dependent nonlinear thermal postbuckling characteristics of a porous functionally graded material (PFGM) microplate with a central cutout with various shapes using isogeometric numerical technique incorporating non-uniform rational B-splines. To construct the proposed non-classical plate model, the nonlocal strain gradient continuum elasticity is adopted on the basis of a hybrid quasi-three-dimensional (3D) plate theory under through-thickness deformation conditions by only four variables. By taking a refined power-law function into account in conjunction with the Touloukian scheme, the temperature-porosity-dependent material properties are extracted. With the aid of the assembled isogeometric-based finite element formulations, nonlocal strain gradient thermal postbuckling curves are acquired for various boundary conditions as well as geometrical and material parameters. It is portrayed that for both size dependency types, by going deeper in the thermal postbuckling domain, gaps among equilibrium curves associated with various small scale parameter values get lower, which indicates that the pronounce of size effects reduces by going deeper in the thermal postbuckling regime. Moreover, we observe that the central cutout effect on the temperature rise associated with the thermal postbuckling behavior in the presence of the effect of strain gradient size and absence of nonlocality is stronger compared with the case including nonlocality in absence of the strain gradient small scale effect.

Isogeometric nonlocal strain gradient quasi-three-dimensional plate model for thermal postbuckling of porous functionally graded microplates with central cutout with different shapes

Vibration and thermal buckling analysis of rotating nonlocal functionally graded nanobeams in thermal environment

Hydrogel–Metal–Organic-Framework Nanoparticle Composites for Immobilization of Active Biomacromolecules

CuO nanomaterials are one of the metal-oxides that received extensive investigations in recent years due to their versatility for applications in high-performance nano-devices. Tailoring the device performance through the engineering of properties in the CuO nanomaterials thus attracted lots of effort. In this paper, we show that nanosecond (ns) laser irradiation is effective in improving the electrical and optoelectrical properties in the copper oxide nanowires (CuO NWs). We find that ns laser irradiation can achieve joining between CuO NWs and interdigital gold electrodes. Meanwhile, the concentration and type of point defects in CuO can be controlled by ns laser irradiation as well. An increase in the concentration of defect centers, together with a reduction in the potential energy barrier at the Au/CuO interfaces due to laser irradiation increases electrical conductivity and enhances photo-conductivity. We demonstrate that the enhanced electrical and photo-conductivity achieved through ns laser irradiation can be beneficial for applications such as resistive switching and photo-detection.

https://iopscience.iop.org/article/10.1088/1361-6528/ac5b52/pdf

Laser modification of Au–CuO–Au structures for improved electrical and electro-optical properties

ZnO nanomaterials have received much attention due to their suitability for applications such as gas sensors, UV detectors, and solar collectors. However, the functionality of ZnO in optical applications is often limited by its wide bandgap (3.15 eV) which restricts the response to shorter wavelengths. In view of this limitation, there has been much interest in tuning the optical properties of ZnO through defect engineering. In this work, we show that processing ZnO thin films with nanosecond (ns) laser irradiation is a simple and effective way to introduce interband defects lowering the bandgap and increasing the sensitivity of ITO/ZnO/ITO photodetector structures at longer wavelengths. In particular, we show that the concentration of oxygen vacancies in ZnO is proportional to laser fluence below 700 mJ/cm2, but that an increase in laser fluence above this value results in thermal heating that anneals the film and lowers the relative abundance of oxygen vacancies. On the other hand, the surface morphology of ZnO does not change significantly even though the fluence reaches 700 mJ/cm2. To illustrate the way in which laser processing can be utilized to improve the optical properties of ZnO films in photodetector applications, we have fabricated transparent ITO/ZnO/ITO stacked structures and measured their response at various optical wavelengths. We find that processing with ns laser radiation is effective in enhancing the responsivity and detectivity of these devices at blue (460 nm) and UV (390 nm) wavelengths. The response of the photodetector is also increased at green wavelengths (570 nm) and red wavelengths (620 nm) when processed with laser fluences in the 480–600 mJ/cm2 range.

Laser engineering of ITO/ZnO/ITO structures for photodetector applications

Traditional Polyvinyl butyral (PVB) laminated glass could not satisfy the rising requirements of sound insulation due to the mass law, especially in the low frequency region. In this work, a...

/pdf/enhancing-sound-insulation-of-glass-interlayer-film-by-14ix9k96.pdf

Shuo Zheng

Papers

Vibration and thermal buckling analysis of rotating nonlocal functionally graded nanobeams in thermal environment

Hydrogel–Metal–Organic-Framework Nanoparticle Composites for Immobilization of Active Biomacromolecules

Laser modification of Au–CuO–Au structures for improved electrical and electro-optical properties

Laser engineering of ITO/ZnO/ITO structures for photodetector applications

Enhancing sound insulation of glass interlayer film by introducing piezoelectric fibers