Role Of Mixture Research Articles

Development of thermo-mechanical simulation of WC/Inconel 625 metal matrix composites laser cladding and optimization of process parameters

Laser cladding (LC) of industrial parts with tungsten carbide (WC)/Inconel 625 composite is highly regarded for its unique properties, for applications such as repair and improvement of surface and mechanical properties. In order to achieve high quality cladding, with minimal impact on the metallurgical structure and minimal stress and distortion caused by high local heating and cooling rate, it is necessary to determine the important parameters of the process, evaluate and investigate the effect of each one. Today, the numerical solution of this process can help predict, understand and evaluate the characteristics of the LC, and control and optimize it. In this research, using the thermo-elastoplastic simulation of the WC/Inconel 625 composite cladding process using finite element method (FEM) and the arbitrary Lagrangian-Eulerian (ALE) solution method with moving mesh strategy, the properties of the created coating have been evaluated. The laser is modeled with a moving Goldak double ellipsoidal heat source and the physical and mechanical properties of the temperature-dependent materials are considered. The physical and mechanical properties of the composite were extracted from the role of mixture and Ashby's method, respectively. Using Taguchi's experimental design method, the effect of important process parameters on output parameters such as dilution, cladding geometry, heat and stress have been investigated. Finally, the optimal parameters as well as the relationship between the parameters and each characteristic have been obtained using the linear regression model.

Stability/instability of magnetorheological core sector structure for mechanical control braking system by the intelligent computer method

ABSTRACT Due to the amazing mechanical properties of the magnetorheological (MR) materials, which can quickly transit from fluid to solid and vice versa, these materials have attracted a lot of attention among designers. So, for the first time, a dynamic stability analysis of a sandwich sector plate made of an MR core and two graphene nanoplatelets reinforced composite (GPLRC) face sheets has been presented. Using the role of mixture and Halpin–Tsai model, material properties of the GPLRC layers have been modeled. For modeling the MR core, shear stress and strain properties of MR fluids have been characterized into pre-yield and post-yield regions. Via first-order shear deformation theory, compatibility equations between the layers, and Hamilton’s principle, motion equations of the structure have been achieved. A generalized differential quadrature method with Chebyshev polynomials greed points has been applied for obtaining the responses of structure. The verification section has been separated into two parts. The first and second ones are verification between the current outcomes with the results of the published report and the machine learning method based on deep neural networks, respectively. Consequently, the results show that some geometrical and physical parameters have an important role in the dynamic stability of the current structure.

Amplitude motion and frequency simulation of a composite viscoelastic microsystem within modified couple stress elasticity

In this research, amplitude motion and frequency simulation of a thick annular microsystem with graphene nanoplatelets (GPL) reinforcement in the framework of the modified couple stress theory (MCST) is undertaken. For obtaining the effective Poisson ratio, and mass density, the role of mixture is employed. As well as this, the Halpin–Tsai micromechanics model is presented for modeling the effective Young module of the current composite microstructure. The mathematical formulations of the current microstructure, size-dependent governing equations and boundary conditions are obtained by considering the MCST’s terms such as higher-order stress tensors, and symmetric rotation gradient into strain energy of the size-dependent GPL reinforced composite (GPLRC) microstructure. Finally, the generalized differential quadrature method (GDQM) is employed to obtain eigenvalue and eigenvectors of the GPLRC microsystem. Afterward, a parametric study is conducted to present the impacts of the radios ratio, length scale parameter, viscoelastic parameter, radial and circumferential mode number, and GPL’s geometry, on the amplitude motion, and frequency characteristics of the GPLRC annular microsystem. The results demonstrate that in the higher value of the radius ratio and time-dependent parameter, we can ignore the influence of length scale parameter on the amplitude and frequency of the annular microsystem. The useful suggestion of this study is that as the thickness of the GPLs increases, the impact of length scale parameter on the frequency of the annular microsystem decreases.

Dynamic simulation of a viscoelastic multi-phase nanocomposite reinforced cantilever spinning disk

This research's objective is a theoretical investigation into the frequency characteristics of the rotary multi-hybrid nanocomposite reinforced (MHCR) cantilever disk (MHCRCD). According to the Kelvin-Voight model, the presented structure is modeled as a disk covered by the viscoelastic foundation. Also, due to rotation, the centrifugal and Coriolis influences are investigated. For obtaining the effective Poisson ratio, and mass density, the role of mixture is employed. As well as this, the Halpin-Tsai micromechanics model is presented for modeling the effective Young module of the MHCRCD. Hamilton’s principle is established for obtaining the governing equations, and various boundary conditions of the rotary MHCRCD. Finally, the generalized differential quadrature method (GDQM) is employed to obtain eigenvalue and eigenvectors of the rotary viscoelastic MHCRCD. In the current research, simply-simply, and clamped-free (cantilever) boundary conditions are applied to edges and R = Ri , R = R0 , respectively. The results demonstrate that fibers’ angle of carbon, carbon nanotubes’ volume fraction, angular velocity, and patterns of carbon nanotubes (CNTs) have a marvelous impact on the frequency and amplitude behavior of the rotary MHCRCD. As an applicable result in related industries, the influence of the angular velocity of the rotary MHCRCD is more impressive in the higher values of the radius ratio.

Bending and stress responses of the hybrid axisymmetric system via state-space method and 3D-elasticity theory

This research presents bending responses of hybrid laminated nanocomposite reinforced axisymmetric circular/annular plates (HLNRACP/ HLNRAAP) within the framework of non-polynomial under mechanical loading and various type of initially stresses via the three-dimensional elasticity theory. The current structure is on the Pasternak type of elastic foundation and torsional interaction. The state-space approach and differential quadrature method (SS-DQM) are studied to present the bending characteristics of the current structure by considering various boundary conditions. To predict the material properties of the bulk, the role of mixture and Halpin–Tsai equations are studied. For modeling the circular plate, a singular point is studied. Finally, a parametric study investigates the impacts of various types of distribution of laminated layers, stacking sequence on the stress/strain information of the HLNRACP/ HLNRAAP. Results reveal that the system's static stability and bending behavior improve due to increasing the value of Winkler and Pasternak factors, and the stress distribution becomes more uniform.

Strength-ductility synergy of Al0.1CoCrFeNi high-entropy alloys with gradient hierarchical structures

A new strategy for strengthening Al0.1CoCrFeNi high-entropy alloys (HEAs) is introduced by architecting the gradient hierarchical structures (GHS). The GHS sheets show a dramatic enhancement in tensile yielding strength and acceptable tensile ductility, outperforming the annealed counterpart, owing to extraordinary strain hardening capacity and nanotwinning activity. The yielding strengths of the GHS sheets are higher than the values calculated by the role of mixture from separate gradient components, suggesting that a synergetic strengthening mechanism of the GHS plays an important role. It may provide a novel guidance to develop HEAs by tailoring and architecting optimized mechanical behaviors from bulk GHS.

Triumphant Miscegenation: Reflections on Beauty and Race in Brazil

In Brazil racial mixture, mestiçagem has been a dominant theme in the political and cultural re-imagination of the nation in the twentieth century. This paper approaches the role of mixture in Brazilian social life from the angle of aesthetics, looking both at Brazilian intellectual history and the commercial and medical beauty industry. It first discusses the aesthetics of race in the works of Brazilian scholar Gilberto Freyre. Second, drawing on ethnographic fieldwork, it shows how cultural constructions of race are reflected in the clinical practice of plastic surgery. Analysing cosmetic practices illuminates central tensions in the ideal of mestiçagem, but also reveals it as a distinct logic of race and beauty that contrasts with multiculturalism. As the beauty industry expands in the developing world, such cultural logics may not be erased but rather incited.