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The present paper portrays the mapping for stochasticity in low-velocity impact responses of functionally graded material (FGM) plates by employing multivariate adaptive regression splines (MARS) surrogate model in conjunction with finite element (FE) approach. The unavoidable stochastic variabilities (caused due to numerous errors involved in manufacturing processes) in material properties of FGM...
The interest in applying piezoelectric materials for modal analysis has been growing in the past few decades. In piezoelectric materials, both electrical and mechanical domains are coupled, i.e., these materials are able to convert electrical energy into mechanical energy and vice versa. Due to this key characteristic, they can be used in several applications as actuators or sensors. Furthermore,...
Bearing and planetary gearbox are important for rotating machinery. However, their faults often cause the stop of the machinery or even fatal casualties. Vibration signal contains the status information of the rotating machinery, which is covered by the strong noise. Stochastic resonance (SR) is a noise-benefit phenomenon, which can detect the weak fault characteristic signal from the vibration signal...
Elastic bulk wave characteristics of doubly curved nanoshell made of functionally graded (FG) anisotropic material are studied. The effective properties of FG anisotropic material vary along the thickness direction. A higher-order shear deformation shell theory and the Bi-Helmholtz nonlocal strain gradient theory are, respectively, utilized to model the nanoshell as a continuum model and predicting...
This study aims to investigate the transverse vibration of size-dependent nano-beam which spins about its longitudinal axis. To this end, nano-beams are modeled based on the Euler–Bernoulli and Timoshenko theories. To consider the size dependency of the nano-beams, the nonlocal elasticity theory is used. By using an exact analytical solution, the governing equations of motions are solved. Comprehensive...
In this paper, the vibration behavior of atomic force microscopy (AFM) micro-cantilever (MC) with a piezoelectric layer in the non-contact mode considering the axial load in the air medium was studied. In the dynamic modes of AFM nano-robot, parameters such as amplitude, frequency and motion phase are used as feedback factors in the control system in order to extract sample surface information and...
Parallel manipulator robots are widely used in a large number of applications because they provide important advantages in terms of superior speeds and accelerations, high stiffness and good dynamic performance. In additive manufacturing (AM), this kind of kinematic structures is being increasingly explored to develop new curved and multi-directional fabrication strategies. Based on this application,...
The objective of this study was to find ways of improving the machining performance of steel considering sustainable development by limiting the application of hazardous lubricant. The textures having the most advantageous shape were employed with hybrid lubrication consisting of graphite powder in combination with the MQL having best suited tribo-rheological properties. The genetic algorithm code...
If a long period has passed after plastic wheel speed sensors were assembled into an automobile, the sensing error may occur when the outer holes of speed sensor crack and water enter through the crack. This not only may put the automobile into the danger of malfunctioning, but the driver may at the psychologically very anxious situation. To resolve this problem, an injection molding method that can...
Film cooling injection from discrete circular holes is widely used in gas turbines to reduce the heat load of the turbine blades. Placing a special designed structure upstream or downstream, the circular hole has been proven to be a new effective way to improve cooling effectiveness in recent years. In the present study, numerical investigations were performed on a row of circular holes over a flat...
In this paper, the combination resonance of a spinning composite shaft with geometric nonlinearity is studied by the method of harmonic balance. The full equations of motion containing the flexural–flexural–extensional–torsional coupling are employed for the analysis. The equations were discretized by both one and two modes, so two different forms of combination resonances can be analyzed. The shear...
Expensive diamond grains remaining within waste diamond grinding wheels and wheel substrate need to be recycled. Electroplated diamond grinding wheel was taken as an example. An idea of “substrate structure-induced cracks (SSIC)” was proposed to solve the disassembly problem of waste electroplated diamond wheels. An assembled substrate for electroplated diamond grinding wheel was designed. Fabrication...
Machines, automobiles, robots, etc., usually employ epicyclic gear trains (EGTs) in their transmission systems. The graph theory-based representation of an EGT has enabled in the development of structural synthesis algorithms for enumerating all the feasible concepts in the form of non-isomorphic graphs. The enumerated EGTs are of importance to an EGT designer during the conceptual stage of design...
In the current study, the flow and heat transfer of MHD Eyring–Powell fluid in a circular infinite pipe is discussed. The rheology of fluid is described by constitutive equation of Eyring–Powell fluid. The solution is constructed for both constant and variable viscosity cases. For variable viscosity case, the viscosity function is defined by Reynolds and Vogel’s models. The solution of each case is...
The degradation of rolling bearings is complex, and traditional methods of degenerating feature degradation are highly dependent on previous research and expertise. However, the traditional methods’ ability for learning the complex relationship between degraded features and large amounts of measured data is limited. So, it is difficult to construct a single health indicator (HI) to predict the degradation...
Rolling bearing is one of the key components in rotating machinery. The working condition of rolling bearing is complex and non-stationary with shock and noise. Thus, fault diagnosis of rolling bearing is of great significance in rotating machinery. In this paper, a novel method called optimization-based improved kernel extreme learning machine is proposed for fault diagnosis of rolling bearing. Firstly,...
In order to calculate analytically the contact status for rail grinding by abrasive belt with an axis deflection, as well as considering limitations of using Hertz contact theory for that, a numerical contact model (NCM) based on the local geometrical relationship between contact wheel and rail surface was developed. The effectiveness and accuracy of the proposed model have been validated by the corresponding...
This paper presents a methodology for the steady-state simulation and optimization of a water–ammonia GAX cycle cooling system for residential and commercial air-conditioning applications. The study is based on an experimental GAX absorber unit described in the literature designed with a cooling capacity of 7.1 kW and uses ammonia–water mixture as the working fluid. The model uses thermodynamic relations...
The present study focuses on the effect of the wall heat loss on a confined swirling diffusion flame. The objective is to assess the effect of changing the wall thermal boundary condition (i.e., from isothermal to adiabatic) on the flow structure, the flame shape, and the mixing behavior. Reynolds-averaged Navier–Stokes equations are solved. The diffusion flamelet model is employed in the simulation...
The present paper deals with a numerical study of turbulent flow which combines a wall jet and parallel offset jet. A parametric study was presented to pick out the offset ratio as well as the offset jet ejection angle influence on the merge point, combined point, upper vortex center and lower vortex center positions. Empirical correlations have been provided as a function of the offset ratio and...
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