Fixtures are extensively used in many industries such as the car industry, to locate and constrain the sheet part during the assembly stage. Fixture layout affects on deformation of sheet parts. Therefore, fixture layout optimization is crucial to the accuracy and quality of products. In addition, the number of clamps that uses in the fixture is another important factor that must be considered in fixture

This study focuses on optimization of process parameters, which may result in improved mechanical properties of the friction stir weldments of AA2014-T651. Plain taper and threaded taper cylindrical tool pin profiles were used for the study. A set of experiments was conducted at different levels of tool rotational and weld speeds using two tool pin profiles. Mechanical properties such as tensile strength

To shape advanced engineering materials, many unconventional machining processes have been developed. Electrical discharge machining is such an unconventional machining process which is very popular nowadays but it is limited by poor material removal efficiency. Electrical arc machining is another unconventional machining process which is quite similar to electrical discharge machining and is now gaining

In the machining processes, vibration suppression is crucial in order to achieve the high precision as well as high-quality surface and increase of the material removal rate. In this paper, an adaptive sliding mode control approach is presented to supress the chattering phenomenon in the boring process in the presence of model uncertainties and unmodeled dynamics. The boring bar is modeled as a cantilever

In this study, a numerical investigation on the dynamic characteristics of a reciprocating mechanism with clearance considering parameter uncertainty is presented. For this purpose, complex space motion between parts is converted into simplified motion of basic component based on the proposed mass substitution model. The contact model in motion parts is established using the Lankarani–Nikravesh model

The instantaneous speed fluctuation is the most direct manifestation of system dynamics behavior, which reflects the running status of the hydraulic system. It is crucial to mine the information contained in instantaneous speed fluctuation and extract them accurately. This paper first introduces the instantaneous speed measurement of the hydraulic system, and it is found that the instantaneous speed

In this study, the laminate analogy technique is utilized to calculate the elastic properties of metal matrix nanocomposites filled with graphene nanoplatelets. The graphene nanoscale fillers are the most commonly used form of graphene inclusions, which are mostly considered to be disk-shaped. With the help of the Eshelby tensor, the effects of three different shapes of graphene inclusions on the mechanical

This work presents integral transform solutions of the bending problem of orthotropic rectangular thin plates with constant thickness, subject to five sets of boundary conditions: (a) fully clamped; (b) three edges clamped and one edge simply supported; (c) three edges clamped and one edge free; (d) two opposite edges clamped, one edge simply supported, and one edge free; and (e) two opposite edges

TiO2 coatings have recently been used as corrosion resistant materials to protect metals in several environments. In this study, the microstructure, phase composition and morphology under different voltages (20, 30 and 40 V) were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The coating corrosion performance was examined

The stiffness of a spindle at high speeds has a significant effect on the quality of the cutting surface and the machining accuracy. However, the spindle stiffness is difficult to be detected directly when the spindle is rotating, and the measured stiffness values are usually coupled with other parts of the spindle–tool system (such as toolholder, spindle–toolholder joint, tool). This paper presents

In this paper, a fast constrained model predictive control algorithm was designed for the active suspension of a half-car model to increase the controller bandwidth so that high frequency displacement disturbance coming from the road can be rejected. To this end, a quasi-LTI model of a semi-active suspension model was controlled by a model predictive controller with orthogonal Laguerre polynomials

As demands increase for goods transportation services, long articulated vehicles are introduced as a viable alternative to conventional heavy-duty vehicles. Nowadays, steering control systems are commonly used for enhancing the stability and handling of articulated vehicles. As situations become more difficult for the movement of a vehicle, the ability of the steering actuators decreases and it will

The multi-stage sequential process with multi-objective is a complex problem to address as the decision made at a particular stage influences the subsequent stage and vice versa. In this article, the effects of input variables of plastic injection, mold, and different plating stages were investigated on different output responses, namely weldline, warpage, length, and various metal plating thicknesses

Welding AISI 304 stainless steel is challenging, especially as fusion-based welding processes (such as arc welding) severely undermine the material's corrosion resistance due to sensitization. Solid-state friction stir welding is one of the most suitable alternatives. Friction stir welding of high-strength high-softening materials such as AISI 304 is difficult mainly because of the non-availability

The dynamic prediction of turning force is an effective means to reflect the changing course and characteristics of the force in the whole cutting process. It is very important to model and predict the turning force and analyze its spectrum characteristics. In order to obtain the dynamic turning force, the circular cutting experiment of 12Cr18Ni9 rotary piece was carried out on the numerical control

In machining process, tool wear is an inevitable consequence which progresses rapidly leading to a catastrophic failure of the system and accidents. Moreover, machinery failure has become more costly and has undesirable consequences on the availability and the productivity. Consequently, developing a robust approach for monitoring tool wear condition is needed to get accurate product dimensions with

The dynamic model of 12-degrees-of-freedom for spur gears pair accounting for nonlinear time-varying stiffness, damping, and coefficient of friction along the path of contact obtained from experimental tests is investigated. The Newmark's integration method is used to solve the equations and obtain the dynamic responses. Elementary mass, stiffness, and damping matrices with torsional and translational

This investigation focuses on the modal analysis of an axially functionally graded material beam under hygrothermal effect. The material constants of the beam are supposed to be graded smoothly along the axial direction under both power law and sigmoid law distribution. A finite element analysis with COMSOL Multiphysics® (version 5.2) package is used to find the Eigen frequencies of the beam. The accuracy

This paper describes the experimental setup of combustion chamber, and the shock loads resultant of gases mixture detonation. The results of experiments performed with fully clamped circular steel plates subjected to detonation of acetylene (C2H2)–oxygen (O2) in various volume ratio and different initial pressure. The energy of deformation of plates is determined by measuring pressure of explosion

When using parallel manipulators as machine tools, the spherical joint has been widely used and replaced by a combination of a universal joint and a rotating unit, but the introduced differences and effects have not been studied in detail. In this paper, an approach to establish the mathematical models of the ideal and combined spherical joints is presented, and the differences between the two spherical

Many studies to find solutions for the optimum synthesis problems of linkage mechanisms for path, motion or function generation have appeared in the literature. However, their main focus has been on the development of optimization algorithms or synthesis methods without the handling of the defect problems or only with consideration of the same assembly mode. Hwang and Chen's pioneering work proposed

In this paper, the stochastic properties of a uniform Timoshenko cantilever beam are investigated systematically. Based on the external viscous damping and Kelvin–Voigt viscoelastic damping, the partial differential equations of the Timoshenko beam subjected to random excitation are derived. The applied load is the concentrated force, and the excitation related to includes the ideal white noise, the

Residual stresses and distortion in welded joints undermine the durability of the structure and prevent a correct assembly of the parts. The principal objective of this study is to find a solution to minimize the residual stresses and distortion induced by submerged arc welding process. Accordingly, first, a thermal simulation of the process was undertaken by the finite-element method, and the results

Bionic strips were designed and processed on the piston of BW-160 slime pump to improve its friction performance, decrease wear mass losses, and prolong service life. Nine stripped pistons were processed and manifested by different strip depths and included angles between stripes and piston surface. A workbench of slime pump piston was created to test the frictional force, oil film width, and wear

This paper presents three-dimensional finite element modeling of nanocomposite materials made from polyethylene polymer reinforced by coiled carbon nanotubes. A method of Python scripting was used to generate representative volume elements in order to determine the mechanical behavior in elastic and plastic zones as well as effective thermal conductivity using the finite element software. The properties

The acquisition of the oil film pressure and forces on the bearing pads through experimentation is crucial to understanding the characteristics of journal bearing. Lots of efforts had been taken in film pressure measurement, and the pressure was obtained at specified position on the bearing pads. However, due to the space and structure constraint, merely very limited number of the point pressure can

The present investigation focuses on theoretical performance of various new environment-friendly refrigerant mixtures as substitutes to high global warming potential refrigerant R22. In this investigation, 34 refrigerants were considered at various composition. In this work, both complex vapor compression cycle (actual cycle) and standard vapor compression cycle (ideal cycle) was considered for the

The present work implements a numerical simulation to investigate the combustion process in a porous-free flame burner. The non-equilibrium thermal condition is performed, and discretization and solving of the governing equations are conducted in a two-dimensional axisymmetric model. In order to simulate the combustion process, a reduced chemical kinetic mechanism of GRI 3.0, which includes 16 species

The double-row self-aligning ball bearing commonly runs with angular misalignment between the inner and outer rings, and the angular misalignment significantly affects the bearing performance. However, the effect of angular misalignment on the dynamic characteristics of the double-row self-aligning ball bearing has not been studied thoroughly. This paper investigates the effect of angular misalignment

Optimization of sequential preventive maintenance has been widely studied. However, some issues need further discussion when considering certain real factors. Hence, an sequential preventive maintenance policy for a mono-unit repairable system with maintenance windows is proposed. The load strength and catastrophic failures of a system are considered in the reliability model, and an optimization of

In the current scenario, the advanced industries are using highly sophisticated types of machinery. These types of machinery use numerous cylindrical components made with superior materials and technology. For obtaining the nano-level finished interior cylindrical surface with high accuracy and high production rate, a newly developed rotational magnetorheological honing (R-MRH) process is employed

In this research, the response surface methodology with a polynomial model was used to represent the experimental data of the combination of steaming, drying, and tempering process for extra-large cashew nuts. The desired values of pre-treatment conditions minimize the broken kernel percentage and maximize the shelling capacity to achieve cost effectiveness. In the this study, the steaming, drying

The stacks of carbon fiber-reinforced polymer (CFRP) and aluminum are widely used in aviation industry due to its excellent mechanical and physical properties. Recently, rotary ultrasonic drilling technology which is recognized as a useful machining method has been introduced to machining these stacks. Thrust force influences the machinability directly such as tool wear, cutting temperature, and hole

Accurate gear profile plays an important role in determining the transmission performance of gear-drive equipment. In this paper, a novel method for extracting gear tooth profile edge is presented. The presented method is based on engagement-pixel image edge tracking (EPIET) technique, and does not rely on the traditional meshing theory. An algorithm for the proposed method is put forward. Firstly

The design of modern mechanical components often requires the use of low-density and high-strength parts. Additive manufacturing presents competence in obtaining format complexity internally (voids, ducts, channels) and externally (shape, holes). However, parts obtained by material extrusion additive manufacturing are highly anisotropic and relatively weak. This paper aims to present a new mechanical

Rotors supported on gas foil bearings have low damping characteristics, which limits its application. A possible solution could be an integration of a gas foil bearing with an electromagnetic actuator. This paper discusses the effect of electromagnetic actuators on the stability of a rotor supported on gas foil bearings. A coupled dynamic model combining the dynamics of gas foil bearing and electromagnetic

In this paper, a method for evaluating the contact stiffness ratio of the elastic rough interface is proposed. The rough contact interface subjected to normal load is replaced by an equivalent thin layer with isotropic material. The interfacial stiffness ratio is characterized using the material parameters of the thin layer. The shear modulus and Young’s modulus of the thin layer are determined by

Simplification of a complex model is an analytical method commonly adopted in engineering design and academic research. A simplified theoretical analysis model can help project planners or researchers to develop an integrative view of the effect of each component on the system performances, which allows them to understand the related engineering phenomena and make proper engineering judgments. Based

Research studies on quadrotors have recently drawn significant interest from academia and industry. Faults and failures handling are the major weaknesses of conventional quadrotor platforms; therefore, an innovative actuation mechanism was introduced to allow tilting the rotors. Tilting rotors of multirotor platforms provide high dexterity for flying between adjacent obstacles and assist the platforms

A hydraulic damper can improve system reliability when it is introduced to an electromagnetic active suspension equipped with a linear motor. In this study, the effect of damping value on the energy consumption of an electromagnetic active suspension system is investigated with an energy-saving perspective. A kinetic model of electromagnetic active suspension is established, and a controller is designed

In this paper, a control system is designed for a vehicle active suspension system. In particular, a novel terminal sliding-mode-based fault-tolerant control strategy is presented for the control problem of a nonlinear quarter-car suspension model in the presence of model uncertainties, unknown external disturbances, and actuator failures. The adaptation algorithms are introduced to obviate the need

In this research, buckling and vibrational characteristics of a spinning cylindrical moderately thick shell covered with piezoelectric actuator carrying spring-mass systems are performed. This structure rotates about axial direction and the formulations include the Coriolis and centrifugal effects. In addition, various cases of thermal (uniform, linear, and nonlinear) distributions are studied. The

In vibratory feeder, material feeding occurs due to the vibration of a trough mounted on helical springs. High vibration amplitude of trough causes the springs to jump and usually results in higher noise level generation and increase in force transmissibility in the support structure of the feeder. Reducing this noise without having significant changes in the dynamics of the feeder unit is a major

The fluid flow characteristics of a turbulent offset jet impinging on a wavy wall surface has been investigated numerically. Two-dimensional Reynolds-averaged Navier–Stokes (RANS) equations are solved by the finite volume method. In the governing differential equations, the convective and diffusive terms are discretized by the power law upwind scheme and second-order central difference, respectively

Intelligent manufacturing is the future development direction of manufacturing industry. There are still some problems lurk in the traditional mode of production, such as “information island” and “network security”, which result in low productivity but high-cost production, and information leakage. With application of the new generation information technology in manufacturing field is expanded, the

In this paper, nonlinear free vibration of a cantilever flexible shaft carrying a rigid disk at its free end (overhung rotor) is investigated. The Rayleigh beam model is used and the rotor has large amplitude vibrations. With the assumption of inextensibility, the effect of nonlinear curvature and inertia is considered. The effect of disk mass on the dynamical behavior of the system is studied in the

The particle velocity and stress in the striker and bar generated by the striker impact on a bar with different general impedance are formulated based on one-dimensional assumptions. Departure of the impact-generated stress wave towards the rear end of the striker and arrival of the release wave from the rear to the front of the striker constitute one impact cycle. In cases where Zs ≤ Zb (Z is the

The frictionless contact problem between an axisymmetric rigid indenter and a layered transversely isotropic medium with surface stresses is considered. The contact pressure is represented as a product of two series based on the solutions of the bulk material and the elastic surface. By using Hankel transforms, the coefficients in the product-series representation are determined by the normal displacement

In the present work, laser beam drilling of a fabricated basalt–glass hybrid composite has been done. From the experimental results, a safe machining zone pertaining to high drill quality with minimum heat affected zone and maximum hole-circularity has been predicted. The prediction of the zone has been done by mathematical modeling and optimization using artificial neural network merged with multi-objective

Composite materials have become popular because of high mechanical properties and lightweight. Aluminum/carbon nanotube is one of the most important metal composite. In this research, mechanical properties of aluminum/carbon nanotube composite were obtained using molecular dynamics simulation. Then, effect of temperature on stress–strain curve of composite was studied. The results showed by increasing

This paper investigates the effect of underwater friction stir welding process parameters on the mechanical properties of the aluminum alloy 6082-T6 joint and further simulates this process using various evolutionary optimization algorithms. Three independent underwater friction stir welding process parameters, i.e. shoulder diameter (in mm) at two levels, rotational speed (in r/min) at three levels

Spindles in precision boring machines usually operate without internal cooling, and thermal error in such spindles is nonnegligible and can severely affect the end-processing quality of the machines. This study aims to investigate the effects that external cooling exerts on the thermal behavior of such spindles. A helical tube cooler is taken for external cooling. An analytical thermal resistance model

The multi-power face gear split flow system is a new type of transmission system, which has the advantages of stable and reliable transmission and strong carrying capacity. And it has great potential in the application of helicopter transmission systems. In this paper, the multi-power face gear split flow system was taken as the research object. Based on the lumped parameter method and Newton’s second

In this study, the calculating principle of the meshing limit line of the conical surface enveloping conical worm pair is put forward systematically. The tooth face equations, the meshing function and the meshing limit function of a conical worm pair are all acquired. Investigating the meshing limit line is come down to solving an equivalent unary nonlinear equation, which is determined from its original

In this article, the assembly interference of spiral bevel gears in a Klingelnberg cyclo-palloid system is analyzed based upon tooth contact analysis and is investigated experimentally. Each backlash in increasing mounting distance of the pinion is calculated step by step, using developed tooth contact analysis. When the backlash increases, the assembly interference does not occur based upon the calculated

Understanding and modeling the constitutive behavior of soft tissues represents an important challenge with significant relevance in medicine and biology. In this paper, we propose a new visco-hyperelastic model to describe the constitutive behavior of soft tissues as an isotropic and homogeneous material. The model is based on the nonlinear framework of continuum mechanics. A generalized Rivlin strain

Quartz-reinforced polyimide composite is a kind of material with anisotropic and nonuniform properties. The machinability has high dependence on fiber orientation θ. This paper presents the first comprehensive investigation on the cutting model of composites based on fiber orientation. A series of cryogenic cooling milling experiments were carried out to study the influence of fiber orientation on

Piezoelectric energy harvesting is an efficient technique among energy scavenging methods employed in asphalt pavements. Several designs are reported in the literature; however, what is less discussed is how to design the harvester. In this paper, a fixed volume of piezoelectric material is considered, and various design parameters are discussed in order to achieve an improved design. The main objective

High-precision profile reconstruction is a key issue in the profile detection and visualization of aero-engine blades. A method based on adaptive step size bat algorithm (ASSBA) for blade profile reconstruction and an adaptive mesh model for visualization analysis of the key machining errors are proposed. Firstly, the original bat algorithm (BA) is improved to introduce the global stage and local search

Rapid manufacturing techniques permit tools and dies to be fabricated in short duration of time with complex geometry. The major contribution of the present research was to fabricate copper complex geometry electric discharge machining electrode by using amalgamation of three-dimensional printing along with pressureless loose sintering. Response surface methodology was employed to study the sintering