Effect Of Material Variation Research Articles

The Effect of Material Variations on Discbrakes to Reduce the Heat that Occurs When Braking Using Transient Thermal Simulation

The Effect of Material Variations on Discbrakes to Reduce the Heat that Occurs When Braking Using Transient Thermal Simulation

Development of Corrosion Resistant Welding Technology for Industrial Applications Study on the Impact of Material Variation and Welding Process

This article discusses the development of stainless welding technology aimed at improving corrosion resistance in industrial applications. The research focuses on the effect of material variation and welding process on the corrosion-resistant performance of welding joints. The research methodology includes the selection of materials with different compositions and the application of various welding techniques. Experiments were conducted to evaluate the microstructure, joint strength, and corrosion resistance properties of the weldments. The results show that material variation has a significant impact on the corrosion resistance of welding joints. The use of certain welding techniques can also affect the corrosion properties of the resulting material. Microstructure analysis provides an in-depth insight into the changes at the microscopic level that affect corrosion resistance. This study makes an important contribution in identifying critical parameters that need to be considered in the development of corrosion resistant welding technology to improve material performance in corrosive industrial environments. In conclusion, a better understanding of the relationship between material and welding process variations and corrosion resistance can help in designing more effective and durable welding technologies for industrial applications. This research has the potential to provide practical guidance for engineers and industry professionals in selecting optimal materials and welding techniques to address corrosion challenges in diverse work environments.

Modeling of Double-Gate Field-Effect Diodes for Analog Applications

As technological trends impose device dimension limitations, exploring other devices apart from metal oxide semiconductor field effect transistor, due to short-channel effects, has become inevitable. Higher ION/IOFF ratios and faster switching rates are quintessential characteristics for nanoelectronics. A field effect diode (FED) is one such device that exhibits greater drive current and low leakages when compared to silicon on insulator technology. Also, the FED fabrication process is compatible with complimentrary metal oxide semiconductor technology. Recently, several approaches have been proposed to tackle the low OFF current problem in FED such as Modified—FED and Side—Contacted FED. The FED structure proposed here is also believed to exhibit lesser short-channel effects, smaller OFF-state current, and higher ON-state current than a regular FED structure. We have explored the possible effects of material variation and work function engineering in our structure. Comprehensive analysis of the proposed device has also been done on some figures of merit such as subthreshold slope, energy-delay product, intrinsic gate delay, etc. thereby making this device suitable for electrostatic-discharge protection. Our numerical investigation promises FED’s efficacy in future logic applications in the nanometre regime.

Effect of material variation on the uniaxial compression behavior of FDM manufactured polymeric TPMS lattice materials

Triple periodic minimal surface (TPMS) based lattice materials are being explored for potential use in energy absorption and biomedical implant applications worldwide. In this study, the mechanical behavior of Schwarz-P TPMS lattice material under uniaxial compression has been compared for two different polymers – PLA and ABS, at different compression speeds from 5 mm/min to 35 mm/min to obtain a comprehensive picture. It was seen that while both material samples showed a layered manner of deformation wherein the stresses varied periodically, they behaved in slight contrast to each other when strain rates varied. The PLA samples showed 10% less compressibility than ABS samples, though both materials exhibited catastrophic failure tendency. The first peak stress increased linearly with the strain rate but the PLA samples show up to 30% higher value than ABS. The ABS samples had less variation between samples compressed at same deformation rate and inter-sample variation of the mechanical behavior was negligible at intermediate deformation rates. In the end, a cumulative picture has been shown where averaged mechanical behavior has been compared for both materials at different strain rates.

The vibration of two-dimensional imperfect functionally graded (2D-FG) porous rotating nanobeams based on general nonlocal theory

A comprehensive vibrational analysis of bi-directional functionally graded (2D-FG) rotating nanobeams with porosities is studied for the first time. The beam is modeled based on general nonlocal theory (GNT) where the beam governing equations are derived depending on two different nonlocal parameters. Unlike Eringen’s conventional form of nonlocal theory, the general nonlocal theory can reveal both hardening and softening behaviors of the material. Here, the attenuation functions are altered in both transverse and longitudinal directions of 2D-FG nanobeam. This feature, which has a significant effect on the vibrational characteristics, has not been considered in previous studies. Moreover, to estimate the effects of the higher-order transverse shear strains on the vibration of the nanobeam, Reddy’s beam theory (RBT), which includes higher-order shear deformation, is employed. The material properties of the 2D-FG rotating nanobeam vary both in the length and thickness directions according to a power law. The generalized differential quadrature method (GDQM) is used to predict the vibration response. Also, the effects of material variation along the length and thickness directions, the rotating velocity of the nanobeam, the porosity volume fraction and the length to thickness ratio of the rotating nanobeam are illustrated and discussed in detail. The investigations performed in this study expose new phenomena for the vibration of nanobeams.

Machining of functionally graded Ti6Al4V/ WC produced by directed energy deposition

Additive manufacturing (AM) technologies offer new processing routes for functionally graded materials. At present, parts built using these processes often require additional processing as a result of the characteristic surface finish limitations synonymous with AM processes. A difficulty thus arises in the post processing of these components as volumes within the part have differing material properties by definition and will therefore exhibit variable machinability.In this study, machining of functionally graded Ti6Al4V/ WC components consisting of a metal matrix composite (MMC) region and a single alloy region produced via direct energy deposition using commercially available tooling is explored. The influence of post processing on surface integrity is investigated and reported. The effect of material variation on cutting forces and tool response along the component is also analysed and reported. Cutting forces within the MMC region are found to increase by as much as 40% which has been subsequently related to the periodic changes in microstructure generated by the layer by layer build strategy. Tool wear mechanisms are investigated and the influence of material pull out on surface integrity of both MMC and single material regions is explored. This study provides an insight into how the layer building strategies, particularly with multiple materials and the resulting variation in microstructure influences the machining of resulting components.

Investigation of Quasi-Static Indentation Response of Inkjet Printed Sandwich Structures under Various Indenter Geometries.

The objective of this investigation was to determine the quasi-static indentation response and failure mode in three-dimensional (3D) printed trapezoidal core structures, and to characterize the energy absorbed by the structures. In this work, the trapezoidal sandwich structure was designed in the following two ways. Firstly, the trapezoidal core along with its facesheet was 3D printed as a single element comprising a single material for both core and facesheet (type A); Secondly, the trapezoidal core along with facesheet was 3D printed, but with variation in facesheet materials (type B). Quasi-static indentation was carried out using three different indenters, namely standard hemispherical, conical, and flat indenters. Acoustic emission (AE) technique was used to capture brittle cracking in the specimens during indentation. The major failure modes were found to be brittle failure and quasi-brittle fractures. The measured indentation energy was at a maximum when using a conical indenter at 9.40 J and 9.66 J and was at a minimum when using a hemispherical indenter at 6.87 J and 8.82 J for type A and type B series specimens respectively. The observed maximum indenter displacements at failure were the effect of material variations and composite configurations in the facesheet.

Modeling of functionally graded smart plates with gradient elasticity effects

ABSTRACTIn this article, the equations of motion for functionally graded plates with surface-mounted piezoelectric layers, while accounting for the gradient elasticity through the modified couple stress model and linear piezoelectricity, are derived using Hamilton’s principle. The formulation includes the coupling between mechanical deformations and the charge equations of electrostatics. The mathematical model developed herein is an equivalent single layer theory for mechanical displacement field and the potential functions. The in-plane displacements are assumed to vary as cubic functions of the thickness coordinate while the transverse displacement is assumed to vary as a quadratic function of the thickness coordinate through plate thickness. The potential function is assumed as the combination of half cosine variation of electric potential and linear variation of applied voltage on outer surfaces. The approach described here is that standard plate models can be enhanced to include the coupling between the charge equations and the mechanical deformations as well as the size dependent effect of micro- and nano-scale structures. An analytical solution of the developed model is presented using the Navier solution technique. A parametric study is performed to study the effect of material variation through thickness of plates, length scale parameters to capture the size-dependent effects, and thickness ratio between piezoelectric layers and the whole plate.

Large deflection analysis of planar curved beams made of Functionally Graded Materials using Variational Iterational Method

In this paper, arbitrarily large in-plane deflections of planar curved beams made of Functionally Graded Materials (FGM) are examined. Geometrically exact beam theory is revisited, but the material properties are considered as an arbitrary function of the position on the cross-section of the beam, to derive the governing differential equation system. Axial, and shear deformations are taken into account. Equations are solved by the method called Variational Iterational Method (VIM). Solution steps are given explicitly. Presented formulation is validated by solving some examples existing in the literature. It is seen that the solution method is easy, and efficient. Deflection values, and deflected shapes of half, and quarter circular cantilever beams made of FGM are given for different variations of the material. Snap-through, and bifurcation buckling of pinned–pinned circular arches made of FGM are examined. Effects of material variation on the deflections, and bifurcation buckling load are examined. New results are also given for arbitrarily large in-plane deflections of planar curved beams made of FGM.

A new simple shear deformation theory for free vibration analysis of isotropic and FG plates under different boundary conditions

Purpose– A new simple parametric shear deformation theory applicable to isotropic and functionally graded plates is developed. This new theory has five degrees of freedom, provides parabolic transverse shear strains across the thickness direction and hence, it does not need shear correction factor. Moreover, zero-traction boundary conditions on the top and bottom surfaces of the plate are satisfied rigorously. The paper aims to discuss these issues.Design/methodology/approach– Material properties are temperature-dependent and vary continuously through the thickness according to a power law distribution. The plate is assumed to be initially stressed by a temperature rise through the thickness. The energy functional of the system is obtained using Hamilton’s principle. Free vibration frequencies are then calculated using a set of characteristic orthogonal polynomials and by applying Ritz method for different boundary conditions.Findings– In the light of good performance of the present theory for all boundary conditions considered, it can be considered as an excellent alternative to some two-dimensional (2D) theories for approximating the tedious and time consuming three-dimensional plate problems.Originality/value– To the best of the authors’ knowledge and according to literature survey, almost all published higher order shear deformation theories have been limited to simply supported boundary conditions and without taking into account the thermal stresses effects. The existing 2D shear deformation theories of Reddy, Karama and Touratier can be easily recovered. Furthermore, this feature can be highly appreciated in an iterative design process where a large number of derived plate models can be tested by selecting only two parameters in a simple polynomial function which is computationally efficient. Finally, new results are presented to show the effect of material variation, and temperature rise on natural frequencies of the FG plate for different boundary conditions.

Effect of material variation on the biomechanical behaviour of orthodontic fixed appliances: a finite element analysis.

Biomechanical analysis of orthodontic tooth movement is complex, as many different tissues and appliance components are involved. The aim of this finite element study was to assess the relative effect of material alteration of the various components of the orthodontic appliance on the biomechanical behaviour of tooth movement. A three-dimensional finite element solid model was constructed. The model consisted of a canine, a first, and a second premolar, including the surrounding tooth-supporting structures and fixed appliances. The materials of the orthodontic appliances were alternated between: (1) composite resin or resin-modified glass ionomer cement for the adhesive, (2) steel, titanium, ceramic, or plastic for the bracket, and (3) β-titanium or steel for the wire. After vertical activation of the first premolar by 0.5mm in occlusal direction, stress and strain calculations were performed at the periodontal ligament and the orthodontic appliance. The finite element analysis indicated that strains developed at the periodontal ligament were mainly influenced by the orthodontic wire (up to +63 per cent), followed by the bracket (up to +44 per cent) and the adhesive (up to +4 per cent). As far as developed stresses at the orthodontic appliance are concerned, wire material had the greatest influence (up to +155 per cent), followed by bracket material (up to +148 per cent) and adhesive material (up to +8 per cent). The results of this in silico study need to be validated by in vivo studies before they can be extrapolated to clinical practice. According to the results of this finite element study, all components of the orthodontic fixed appliance, including wire, bracket, and adhesive, seem to influence, to some extent, the biomechanics of tooth movement.

Analysis of Simply Supported Thin FGM Rectangular Plate Resting on Fluid Layer

The deflection response of initially stressed functionally graded material rectangular plates subjected to distributed impulsive lateral loads and resting on a fluid layer is obtained. In the current work, material properties are chosen to be graded in the thickness direction according to a simple power law distribution. The developed artificial neural network (ANN) model uses some output results obtained using differential quadrature method. The effects of material variation, initial stress, and fluid reaction on the plate deflection are obtained. Application of ANN method to the current problem showed that ANN technique, with less effort and time, is very efficiently capable of simulating and predicting the plate deflection and the effect of different parameters.

Free vibration of an axially functionally graded pile with pinned ends embedded in Winkler-Pasternak elastic medium

In the present study, free vibration of an axially functionally graded (AFG) pile embedded in Winkler-Pasternak elastic foundation is analyzed within the framework of the Euler-Bernoulli beam theory. The material properties of the pile vary continuously in the axial direction according to the power-law form. The frequency equation is obtained by using Lagrange's equations. The unknown functions denoting the transverse deflections of the AFG pile is expressed in modal form. In this study, the effects of material variations, the parameters of the elastic foundation on the fundamental frequencies are examined. It is believed that the tabulated results will be a reference with which other researchers can compare their results.

Overview of Board-Level Solder Joint Reliability Modeling for Single Die and Stacked Die CSPs

Modeling can efficiently investigate the reliability of new packages, saving time, manpower, and cost for conducting actual tests; A good model is useful for short time-to-market. In this paper, only journal and technical magazine papers are reviewed, many of which report modeling analyses of single die and/or stacked die chip-scale packages. They are summarized regarding the methods, design parameters, and/or results. Brief comparisons are provided on similarities and differences of the effects of the common design parameters on solder-joint reliability. The effects of variations in materials, package designs, the number of dies, test conditions, and board geometry can be investigated efficiently by thermal cycling modeling or drop test modeling.

Fractal dimension modelling of surface profile and optimisation in CNC end milling using Response Surface Method

The influence of machining parameters, viz., spindle speed, depth of cut and feed rate on fractal dimension of surface profile produced in CNC end milling is investigated. Experiments are conducted for three different workpiece materials to see the effect of material variation in this respect. The second order mathematical models, in terms of the machining parameters, have been developed for fractal dimension prediction using Response Surface Methodology (RSM). It is found that the response surface model for fractal dimension is specific to workpiece materials. Optimum cutting conditions with respect to fractal dimension are also obtained using the response optimisation technique.

An Experimental Investigation on Damage Loads of Butterfly Joints in Composite Structures

This study is performed experimentally to investigate damage forces formed on glass-fibre laminated composite plates that are jointed with a component in the shape of butterfly. Pressing it into the mould in a hot press machine produced a glass fibre-epoxy composite plate. Specimens and locking parts in the shape of butterfly were cut using water jet. Experiments were performed in different values of the ratio of the end width of butterfly to the width of the specimen ( w/ b), the ratio of the middle width of butterfly to the end width of butterfly ( x/ w) and the ratio of the half-length of butterfly to the width of the specimen ( y/ b). Using these values, the effects of joint geometry parameters were evaluated. To be able to see the effect of material variations as well, the joint lock in the shape of butterfly was made up of both metal and composite materials. Although the loading capacity of the composite butterfly is lower than that of the metal butterfly, it carries loads for much longer times. Before a composite structure develops damage, damage occurred in the composite butterfly can be seen and, with the repair of the butterfly lock, the life of the composite structure can be extended.

The effects of material variations on aircraft inspection schedules based on stochastic crack growth model

Based on stochastic crack growth model, the effects of material variations on aircraft inspection schedules are investigated in this paper. Fatigue tests are performed to obtain the log standard deviation of fatigue lives due to material variations. The test materials are 7475-T7351, 7050-T7451, 2024-T851 and 2124-T851. The effects of material variation on inspection schedule are significant. For a large material variation, the inspection schedule should be shortened for conservative consideration. The effects of sample size on the material variation under 50% and 95% confidence levels are investigated numerically. The results of this study provide a guideline to allocate resources of fleet planning more realistically by compromising between the cost (or time) of fatigue experiments and aircraft inspections.

Effect of material variations on performance of double-recessed gate power pseudomorphic high electron mobility transistors in monolithic microwave and millimeter wave integrated circuit applications

We report the effect of start epi-material variability on the performance of double-recessed power pseudomorphic high electron mobility transistors. Variation in channel-recess depth, which is related to variation in the start material, is critically linked to rf performance of monolithic microwave and millimeter wave integrated circuit high power amplifiers. For high yield, it is important to control the channel recess, which in turn has implications on acceptable variation in epi-material. Design tweaks can relax channel-recess tolerance limits, but it is still important to account for material variation.

Thermomechanical Cracking in the Vicinity of a Near-Surface Void Due to High-Speed Friction Load

This paper discusses the temperature distribution and the stress state in the vicinity of a near-surface rectangular cavity. They occur when the solid is subjected to the Coulomb frictional loading of an asperity moving at moderately high speed. The finite difference method is employed to calculate both the temperature and stress fields. The energy balance method is applied at the corners of the rectangular cavity to resolve the problem of singularities in the temperature field there. The stress singularity at each corner is represented by a special element that is introduced representing the behavior of the known stress singularity at the corner and its surrounding vicinity. Results show that the thermal stress effect dominates the stress field and eventually leads to failure. When a defect, such as a cavity, exists, the stress state that determines the failure phenomenon is more severe and can be quantified depending on the location of the cavity. These results were determined through a numerical computation based on the material properties of Stellite III. However, the parametric effect of material variations including changes in both thermal and mechanical properties were also considered. The study of the cavity location also established the existence of a critical cavity location. This location is defined by the critical ligament thickness (thickness between the wear surface and the top edge of the cavity), at which the cavity-influenced thermal tensile stress reaches a maximum. This thickness is important to designers when cavities at coating/substrate interface are either unavoidable or are too expensive to control in fabrication.

Resistance spot welding of galvanized steel: Part II. Mechanisms of spot weld nugget formation

Dynamic inspection monitoring of the weld current, voltage, resistance, electrode displacement, and force was performed in conjunction with a detailed study of the effects of material variations and weld process parameter modifications on resistance spot welding of coated and uncoated steels. In order to determine the mechanisms of weld nugget formation and growth, scanning electron microscopy photos were taken of the developing nugget. These physical changes were then related to the dynamic inspection curves and the welding current lobe. The effects of material variations and weld process modifications, the results of which were presented in Part I, can be explained through an understanding of these mechanisms.