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In the context of the triple-phase lag model, comparison studies are conducted between the memory-dependent derivative and fractional order derivative on the propagation of plane waves in a half-space of initially stressed transversely isotropic piezothermoelastic material. The coupled governing equations of the considered model involving relaxation time, time delay, fractional order parameter, and kernel function are selected according to specific problems and solved using the normal mode analysis technique and obtaining the analytical expression. The non-dimensional temperature, displacement, electrical displacements, and stresses at different values of the fractional order parameter and time delay factor are obtained graphically. [ABSTRACT FROM AUTHOR]

Seismic wave propagation is a complex process that is influenced by various factors, including the elastic properties of the medium and the initial stress condition. In this study, we have investigated the reflection and refraction phenomena of plane waves at orthotropic layer between two triclinic half-spaces with initial stresses. It has been assumed that the lower and upper half-spaces are composed of highly anisotropic triclinic crystalline material. The calculations have been performed to determine the phase velocity of the quasi waves. The theoretical expression of reflection/refraction coefficients and energy ratios of each reflected and refracted quasi waves has been derived in closed form. It has been shown that the reflection/refraction coefficients, phase velocity and energy ratios depend on the incident angle, initial stress, propagation vector, displacement vector and elastic properties of media. Numerical results demonstrate the significant impact of initial stresses on reflection and refraction coefficients and energy ratios. The slowness surface diagrams are established for various waves and energy conservation law is verified to ensure correctness of the study. This research contributes to understanding seismic wave propagation in complex anisotropic media, with applications in forward and inverse geophysical reflection/refraction problems. The findings can be used to improve our understanding of the Earth's internal structure and seismic exploration and monitoring. [ABSTRACT FROM AUTHOR]

Quartz crystals are widely used in sensors, auctors, filters, and resonators due to their excellent piezoelectric properties and operational stability. As electronic devices continue to miniaturize, understanding the nonlinearity in quartz crystal structures becomes increasingly important. This study aims to support the design of high-sensitivity piezoelectric sensors by analyzing the thickness-mode nonlinear vibration of randomly cut quartz crystals, incorporating the effects of initial stress. Specifically, a theoretical framework is developed to determine the nonlinear vibration frequencies of the fast and slow thickness-shear modes, as well as the thickness-stretch mode in a randomly cut quartz crystal. The study explores the dependence of vibration frequencies on nonlinear vibration amplitude and initial stress. To ensure that frequency variations are attributed to initial stress, the nonlinear vibration amplitude is maintained at a reasonable value. Furthermore, the effects of cut orientation on frequency variation under a given initial stress are examined to identify the optimal cut for frequency sensitivity. Our results demonstrate that quartz crystals exhibit high sensitivity to initial stress, with the fundamental vibration mode showing the largest frequency shift despite having the lowest frequency. This mode proves particularly suitable for sensor applications. The study identifies the cut orientation with the optimal frequency sensitivity and provides insights that could guide the design of piezoelectric sensors and expand their application. [ABSTRACT FROM AUTHOR]

AbstractThis paper investigates Love-type wave propagation in a multilayered, elastic, prestressed solid half-space with voids. Using the Haskell matrix method, the dispersion relation is derived for a stress-free boundary surface. Two distinct dispersive fronts of Love-type waves, propagating at different speeds, are identified. One behaves like waves in a prestressed elastic half-space, while the other is novel due to voids. Analytical expressions for three-layered and two-layered models are provided. Graphical representations compare the dispersion curves, highlighting differences and dependencies. The study explores how void parameters, initial stress, and layer thickness influence phase velocity, with applications in various engineering fields. [ABSTRACT FROM AUTHOR]

In this paper, a discussion on the forced vibration of a transversely isotropic piezoelectric plate with finite dimensions subjected to a time-harmonic force resting on a rigid foundation is carried out. Here, we assume that the plate is poled along the perpendicular surface and bi-axial initially stressed in their reference configuration. The three-dimensional linearized theory of electro-elastic waves in initially stressed bodies (TLTEEWISB) is applied to the initially-stressed piezoelectric plate. A general formulation of the governing equations of motions is provided according to the piece-wise homogeneous body model, and then the three-dimensional finite element modeling (3D-FEM) is developed as a solution procedure in terms of weak formulation and virtual work principle. The objective of this paper is to present the results regarding the frequency response of the piezoelectric rectangular plate and the influence of the initial stress factor on the system. Numerical examples imply that while the increasing aspect ratio of the plate prevents the resonance mode of the dynamic force, the increasing thickness ratio exceeds this mode. Further, it is also demonstrated and discussed in detail that the initial stress state has a considerable influence on this mode. [ABSTRACT FROM AUTHOR]

GH4169 thin-walled parts are widely used in aerospace due to their high-temperature, corrosion resistance, and fatigue strength. However, they often deform from machining-induced residual stress, which is a significant unresolved manufacturing challenge. Additionally, initial residual stress from previous steps critically impacts subsequent processes. This study found that the residual stress of side milling of thin-walled parts under smaller cutting parameters is mainly caused by mechanical effects, and the influence of milling heat can be ignored. In this study, an analytical prediction model for residual stress of multi-step side milling thin-walled parts based on the deformation of thin-walled parts is proposed for the first time, which is suitable for smaller cutting parameters. Then, the proposed model is examined the mechanisms through which residual stresses develop during side milling and defined the applicability of model based on specific assumptions. To validate these assumptions, an experimental setup was devloped to simulate the movement of the heat source during milling. Subsequent two-step side milling experiments on GH4169 confirmed the accuracy of the analytical prediction model in predicting the residual stresses of multi-step side milling in thin-walled parts. It was observed that higher equivalent bending stiffness in thin-walled parts correlates with reduced machining deformation. The analytical model also provides a strategic approach to control machining deformation by managing the equivalent bending stiffness of the parts.

Abstract The purpose of the current study is to establish a novel mathematical model in the p-waves in a photothermal semiconducting medium with an internal heat source. The fundamental equations in the context of isotropic and homogeneous medium have been presented. For the solution of the required problem, the normal mode analysis along with the displacement components, stress components and temperature has been utilized. For graphical representation of different physical quantities such as displacement components, stress components and carrier density as well as the temperature distribution. Using MATLAB R2023a software, a parametric analysis is performed, and the resulting data is represented graphically. A comparison is made to show the effect of the new parameters on the phenomenon. A graphic representation of the relationship between rotation, magnetic field, and initial stress in relation to the fluctuations in non-dimensional field quantities is provided, along with an analysis of the findings.

This research offers an in-depth exploration of the mechanical behavior of square steel tubular columns reinforced with concrete under axial compression. The study particularly focuses on how initial conditions, including initial stress and structural defects, influence the columns' performance. By employing ABAQUS for finite element analysis, the investigation covers a broad spectrum of slenderness ratios, systematically assessing how these factors affect the structural integrity of the columns. The analysis reveals that while initial stress tends to reduce the peak load-bearing capacity, it paradoxically enhances the ductility of the columns, a critical aspect of their performance under load. Conversely, initial defects, particularly in slender columns, exacerbate instability, leading to significant reductions in load-bearing capacity. These findings highlight the pivotal role of initial conditions in shaping the mechanical behavior and overall safety of steel-reinforced concrete columns. The study's insights contribute to a deeper understanding of the load-bearing mechanisms and provide a robust framework for improving the precision and dependability of structural design. By integrating considerations of initial conditions into the design process, engineers can significantly bolster the safety and durability of composite columns, especially in high-risk applications such as high-rise buildings and bridges. [ABSTRACT FROM AUTHOR]

This manuscript addresses a significant research gap in the study by employing a mathematical model of photo thermoelastic wave propagation in a rotator semiconductor medium under the effect of a magnetic field and initial stress, as well as ramp-type heating. The considered model is formulated during the photothermal theory and in two-dimensional (2D) electronic-elastic deformation. The governing equations represent the interaction between the primary physical parameters throughout the process of photothermal transfer. Computational simulations are performed to determine the temperature, carrier density, displacement components, normal stress, and shear stress using the application of Lame's potential and normal mode analysis. Numerical calculations are carried out and graphically displayed for an isotropic semiconductor like silicon (Si) material. Furthermore, comparisons are made with the previous results obtained by the others, as well as in the presence and absence of magnetic field, rotation, and initial stress. The obtained results illustrate that the rotation, initial stress, magnetic field, and ramp-type heating parameter all have significant effects. This investigation provides valuable insights into the synergistic dynamics among a magnetization constituent, semiconducture structures, and wave propagation, enabling advancements in nuclear reactors' construction, operation, electrical circuits, and solar cells. [ABSTRACT FROM AUTHOR]

The purpose of this study is to analyze the features of a moving Griffith crack in an initially stressed infinitely long and finitely thick isotropic strip with moving parallel punches of constant load acting on its boundaries owing to plane wave propagation under point loading. Coupled singular integral equations and singularities of the Cauchy-type are used to formulate the present model, Dirac delta function is employed to analyze point load located at the moving crack edge, and Hilbert transformation properties are used for obtaining stress intensity factor (SIF) with constant point loading. Numerical simulations and graphical illustrations are performed to analyze the influences of the prevalent parameters, viz. initial stresses, punch pressure, distinct positions of point load, length and speed of the crack on the SIF for the considered isotropic material strip. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of the current manuscript is to investigate the reflection of plane waves in a rotating, two-dimensional homogeneous, initially stressed, nonlocal orthotropic thermoelastic solid half-space based on dual-phase-lag model. Design/methodology/approach: The reflection phenomenon has been utilized to study the effects of initial stress, rotation and nonlocal parameter on the amplitude ratios. During the reflection phenomenon three coupled waves, namely quasi displacement primary wave (qP), quasi thermal wave (qT) and quasi displacement secondary wave (qSV) have been observed in the medium, propagating with distinct velocities. After imposing the suitable boundary conditions, amplitude and energy ratios of the reflected waves are obtained in explicit form. Findings: With the support of MATLAB programming, the amplitude ratios and energy ratios are plotted graphically to display the effects of rotation, initial stress and nonlocal parameters. Moreover, the impact of anisotropy and phase lags is also observed on the reflection coefficients of the propagating waves. Originality/value: In the current work, we have considered rotation and nonlocality parameters in an initially stressed orthotropic thermoelastic half-space, which is lacking in the published literature in this field. The introduction of these parameters in a nonlocal orthotropic thermoelastic medium provides a more realistic model for these studies. The present work is valuable for the analysis of orthotropic thermoelastic problems involving rotation, initial stress and nonlocality parameters. [ABSTRACT FROM AUTHOR]

Channel steel-reinforced brick column technology has gained significant popularity in rural China due to its convenience and cost effectiveness. However, current research on channel steel reinforcement is sparse, and engineering applications often rely solely on construction experience. This reliance leads to significant construction errors, inconsistent reinforcement effects, and, in some cases, tragedies such as the collapse of Changsha's "4.29" self-built houses. Therefore, in this paper, experimental and simulation studies on brick columns reinforced with external channel steel were conducted, and the results show that channel steel reinforcement can significantly enhance the axial load capacity of brick columns. However, increased initial stress levels and height-to-thickness ratios substantially reduce the reinforcement effect. Under axial pressure, the outer channel steel fails mainly through bending and buckling instability. Still, due to its good ductility, its failure occurs later than the brick column after being restrained by sufficient wall screws. Based on the experimental and simulation results, a method for calculating the axial compressive bearing capacity of the reinforced column is proposed, providing theoretical support and engineering guidance for applying this reinforcement method. [ABSTRACT FROM AUTHOR]

A rotating system that includes an initially stressed piezo-electric substrate was the subject of an analytical study of the SH waves. The substrate and vacuum bonding are in good contact with the corrugation, and the top border is treated as stress-free corrugation. About the upper barrier that is both electrically open as well as electrically short scenarios are taken into consideration. Dispersion equations for circumstances with a corrugated interface that are both electrically short as well as electrically open have been found. The SH wave characteristics through the framework suggested and circumstances dependent on different geometrical and physical factors have been investigated based on the numerical findings. The study looks at the simultaneous simulated outcomes of a number of physical factors that were produced in Mathematica 7 and include rotation, inhomogeneity, phase velocity, initial stress, and corrugated interface of SH wave distribution in a structure under discussion. The model under examination has potential applications in the creation of surface acoustic wave devices.

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The present work investigates SH-wave regulation phenomena into a magneto-elastic transversely isotropic (MTI) strip clamped between a coated Newtonian viscous liquid layer and a heterogeneous elastic half-space. The classical dynamical coupled theory has been employed to examine the problem. Whittaker special function and variable separable technique have been employed to determine the exact solution of the governing equations. A closed-form dispersion equation for the SH-wave has been developed for this boundary conditions-based problem. The validity of our model has been examined in terms of special cases and compared with the classical Love wave equation. Numerical and graphical analyses have been executed for six numerical examples of the MTI layer namely; beryl, magnesium, cadmium, zinc, cobalt and isotropic. Therefore, a comparative study has been developed to examine the velocity profile of the wave for these different MTI examples through several graphs. The results show that the presence of magnetic field, viscosity, initial stress and gravitational field in the structure have major effects on the wave velocity. This model has huge potential to deal with many commercial and industrial applications in acoustic engineering, geotechnical engineering, ultrasonic, earthquake engineering, geophysics, etc. [ABSTRACT FROM AUTHOR]

Since the layer of the Earth is non-homogeneous and initially stressed, this paper has framed to discuss propagation of torsional type surface wave in an initially stressed poroelastic medium sandwiched between a non-homogeneous layer with linear type variation in density and rigidity and a half-space of heterogeneous medium with exponential type variation in density and rigidity. Dispersion equation of this kind of wave has been obtained with the help of Whittaker's expansion and separation of variables method under some specified boundary conditions. The effect of non-homogeneity related with layer and half-space and initial stress of sandwiched medium have been illustrated based on their graphical discussion. It has been found that the presence of non-homogeneity in the material enhances the phase velocity but it also enhances the phase velocity with descending values of initial stress. [ABSTRACT FROM AUTHOR]

Purpose: The current manuscript is devoted to scrutinize the effects of nonlocal parameter, internal heat source, and initial stress on the interactions caused by a moving thermal load in a generalized thermoelastic solid half-space. Methods: The medium is assumed to be initially stressed and has uniform temperature. The problem has been modeled by employing the modified Green–Lindsay theory to carry out the investigation.The governing equations are handled with an analytical–numerical technique based on normal mode. In this technique, one gets exact solution without any assumed restrictions on the field variables. The normal mode technique is applicable to a wide range of problems in thermodynamics and thermoelasticity. Results and Conclusions: Expressions for displacement, stresses, and temperature in the physical domain are obtained. The problem is illustrated by computing the numerical values of the field variables for a copper like material. Comparisons of the physical quantities are shown in figures to study the effects of nonlocal parameter, internal heat source, initial stress, and velocity of the thermal load. Some particular cases of interest have also been inferred from the present problem. Originality/Value: In this article, we have investigated the effects of nonlocal parameter, internal heat source, initial stress, and velocity of the thermal load on the thermoelastic medium. Although various investigations do exist to observe the disturbances in a thermoelastic medium under the effects of different parameters, but the work in its present form, i.e., the disturbances in a thermoelastic medium in the presence of initial stress, nonlocal effect, and internal heat source under modified Green–Lindsay model have not been studied till now. The present work is useful and valuable for the analysis of problems at nanoscale level involving moving heat source, initial stress, and elastic deformation. [ABSTRACT FROM AUTHOR]

Objective: This study investigates the influence of the Thomson effect on the behavior of a diffusive magneto-thermoelastic medium with initial stress and the dual-phase-lag (DPL) model. Methods: The normal mode analysis is utilized for solving the problem. The copper material was chosen for numerical assessments. The results are presented graphically for various physical quantities. Results: A comparison is made between the DPL model and the Lord and Shulman (L-S) theory, both in the absence and presence of the Thomson effect parameter as well as at two different values for the phase lag of heat flux. Conclusions: The findings provide insights into the impact of the Thomson effect on the behavior of the magneto thermoelastic medium, highlighting the differences between the DPL model and the L-S theory in different scenarios. This type of work has many applications in rock mechanics, geophysics, and petroleum industries. This work may be helpful for those researchers who are working in material science, smart materials, and new material designers. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this work is to study the wave propagation in a rotating fiber-reinforced thermo-viscoelastic solid. Methods: The analytical technique used to obtain the ordinary differential equations was normal mode analysis. In this article using the modified Green-Lindsay (MGL) theory and the Green-Lindsay (G-L) theory. Results: The numerical calculations have been completed, and the physical fields have been determined using the proper boundary conditions. The effects of rotation, viscosity, and magnetic field are discussed. Conclusion: Overall, the research on the rotation and magnetic field effect on fiber-reinforced thermo-viscoelastic have a significant influence on all the physical variables and several potential practical implications and engineering applications in various fields such as environmental, chemical, and energy engineering. [ABSTRACT FROM AUTHOR]

Purpose: This study analyzed the impact of initial stresses on the propagation of Love-type waves in a fiber-reinforced viscoelastic layer situated between an isotropic inhomogeneous half-space and an orthotropic viscoelastic layer. The aim of the purposed work is to investigate how various factors such as initial stresses, viscoelastic properties, thickness ratio, inhomogeneity, and reinforcement affect wave propagation in the layered structure. Methods: The separable variable method is used to obtain the displacement components for the considered layers and half-space. By applying suitable boundary conditions, the dispersion relation for Love-type wave propagation derived. The dispersion relation was then examined for different cases, considering factors such as initial stresses, viscoelastic properties, thickness ratio, inhomogeneity, and reinforcement equal to zero. Numerical computations were performed using the MATHEMATICA software, and the results were graphically depicted. Results: The study successfully obtained the dispersion curves, which illustrated the influence of various parameters on Love-type wave propagation. The results showed how initial stresses, viscoelastic properties, thickness ratio, inhomogeneity, and reinforcement affected the wave propagation behavior. Conclusion: The findings of the study confirmed the validity of the mathematical model developed in this study, as the derived dispersion relation simplified the pre-existing velocity wave equation for Love waves. The analysis of dispersion curves demonstrated the significant effects of initial stresses and other parameters on the phase and damping velocity of the Love-type wave in the fiber-reinforced viscoelastic layer. The study enhances our understanding of Love wave propagation and its practical applications in structural engineering, earthquake engineering, non-destructive testing, material science, and geophysics. [ABSTRACT FROM AUTHOR]

Abstract With depth increase of many mines, the damage of surrounding rock by high ground stress cannot be ignored under the blasting excavation method. In view of the strong disturbance of surrounding rock caused by dynamic excavation and unloading under high initial rock stress conditions, based on the elastic unloading theory, the analytical solution of dynamic excavation and unloading stress is given using the residue theorem and Laplace inverse transform. The stress field distribution under the coupling effect of blasting load and initial rock stress is described. By making a rock model and implementing biaxial loading using a drop hammer to simulate the impact load, radial cracks generated by the impact stress wave and circumferential cracks generated by unloading during excavation were captured, and the stress change curve during excavation was monitored. The monitoring curve and theoretical curve have consistency in trend. Under the coupling effect of blasting load and initial stress, surrounding rock will generate tensile stress and broken, and the unloading effect of initial stress occurs after the blasting load, which causes tensile damage to the surrounding rock. The stress field curve plotted by the theory explains well the crack propagation caused by the coupling effect of blasting load and initial stress.

Present research with the aid of multivariate analysis of variance explores the closed-form dynamics of the poroelastic nanocomposite sandwich plate. Additionally, graphical optimization of the system's vibration by proper adjusting the involved parameters is provided by employing response surface methodology. p-value and F-value tests are executed to determine the contribution percentage of each parameter on the dynamics of the structure. The nanocomposite face-sheets are made of graphene-platelets reinforced polymer. The main relations governing the dynamics of the initially stressed sandwich system are defined in the background of theory known as linear poroelasticity. Bidirectional format of discrete singular convolution approach (2D-DSCA) is employed in order to determine the design-points' dynamic performance. Validity of the applied solution procedure is tested through comparison with the outcomes of the first-rate articles. In this research, it is revealed that the graphical optimization is a reliable way to determine the proper adjustment of the parameters for achieving the optimum vibration performance. Moreover, it is observed that the aspect ratio of the plate is the most decisive factor in the free oscillation response of the sandwich plate compared with other factors whose influence are examined in the present article including GPL's weight-fraction, GPL's dispersion patterns, in-plane initial stresses, and the poroelasticity coefficient. [ABSTRACT FROM AUTHOR]

This research aims to study the different phenomena of generalized Rayleigh waves (RWs) in composite structures with piezoelectric material and corrugated surfaces. A thin piezoelectric layer that is precisely attached to an elastic substrate with initial stresses makes up the structure under consideration. By resolving the related electromechanical field equations, expressions for the displacement potential function are produced for both the elastic substrate and the piezoelectric layer. The frequency equations of the studied wave have been discovered as determinants for electrically open and short conditions. There have been both numerical illustrations and graphical demonstrations. On the stage speed of the combined RW, the impact of the grooved border, initial pressure, piezoelectric constant, dielectric constant, and thickness of the piezoelectric layer have been studied. Additionally, the analytical solution to the issue is compared to and shown to be in good agreement with the stiffness matrix approach result. This study offers a theoretical foundation for creating and developing piezoelectric composite-based devices. It has been found that the generalized RW velocity declines with the increase of the values of e 1 5 ̃ and ε 1 1 and an inverse relationship has been found with the increase of the value of H. In addition, it has also been noticed that the velocity profile of the generalized RW is greatly influenced by the size of the corrugation (measured at the upper layer). [ABSTRACT FROM AUTHOR]

In this paper, we study Scholte's waves propagating along the interface of micropolar solid and liquid media, considering the effect of initial stress and impedance boundary surface. We obtained the phase velocities of basic elastic waves in both media and used them to derive the secular equation of Scholte's wave. We found that the initial stress in the solid material does not affect the speed of basic longitudinal waves. After solving the secular equation, we obtained the speed of Scholte's wave and the corresponding attenuation. We observed that Scholte's surface wave obtained at the micropolar solid–liquid interface is inhomogeneous and dispersive. We investigated the effects of initial stress, Tiersten's impedance boundary condition, and micropolar solid parameters on Scholte's wave and basic shear waves. Numerically, these effects are computed for a particular model using the appropriate value of the parameters, and the results are illustrated graphically. This paper also contributes to not only understanding the behavior of Scholte's waves in micropolar solid–liquid interfaces but also the factors that affect the propagation. [ABSTRACT FROM AUTHOR]

This paper aimed at studying the effect of initial stress and impedance boundary surface on the elastic waves propagation in transversely isotropic materials. The governing equations of transversely isotropic materials with initial stress are treated in the x y -plane to obtain the phase velocities of two waves, quasi-longitudinal (q P) and quasi-transverse (q S) waves. The normal mode operation is employed to obtain the expression of the displacement components and stress components. The problem of reflection of incident waves at the impedance boundary of transversely isotropic material is also investigated in the presence of initial stress to obtain the amplitude ratios of reflected waves. The variations of displacement and force stress are illustrated with respect to the axis of propagation by employing amplitude ratio expression. The effect of initial stress and impedance parameters on the expression of displacement and force stress as well as amplitude ratios of transversely isotropic materials are illustrated graphically for a particular model. [ABSTRACT FROM AUTHOR]

In this study we apply multi-temperatures theory to the two-dimensional deformation of a homogeneous, isotropic, thermoelastic half-space with voids under the influence of initial stress. The problem was developed within the context of Lord-Shulman theory. The methodology used here is normal mode analysis to solve the problem and get exact expressions for displacements, stresses, strain, conductive temperature, thermodynamic temperature, and change in volume fraction field. These quantities constructed in the physical domain are displayed graphically. The numerical results of these quantities for magnesium crystal-like material are shown to represent the influence of multi- temperatures and initial stress. [ABSTRACT FROM AUTHOR]

The purpose of the current study is to establish the deformation in a two-dimensional, isotropic, rotating half-space with gravitational field and initial stress that also has a heat source at the half boundary-space under magnetic field for Green and Naghdi II model. For the solution of the required problem, the methodologies of normal mode and approximate eigenvalues has been utilized. For graphical representation of different physical quantities such as displacement components, stress components, as well as the temperature distribution, Matlab software has been used. These results were compared with previous results in the same direction, and it was found that the treatment method for the aforementioned problem may form a basis for examining the effect of each of the gravitational field, magnetic field, rotation, and initial pressure on a thermally elastic body in the form of half an area without energy decay when neglecting some external influences. [ABSTRACT FROM AUTHOR]

The influence of transmission of Love-type waves through a layer of functionally graded piezoelectric material (FGPM) placed within a pre-stressed piezoelectric layer and irregular viscous sandy half-space under hydrostatic stress has been discussed analytically. The irregularity has been opted as rectangular for the lower viscous sandy half-space. The Wentzel-Kramers-Brillouin method is utilized to find an asymptotic solution of a 4th order differential equation with variable coefficients and variable separation method is a critical tool in the upper layer and lower half-plane. In contrast, in the intermediate layer, theoretical derivations are discussed by the WKB technique. Dispersion relation for a Love-type wave is established for electrically open cases and sort cases. An impact of different parameters used in the problem on the phase velocity of a Love-type wave has been depicted graphically. This study is beneficial for constructing and improving surface acoustics wave (SAW) devices. Some particular cases have also been demonstrated for the validation of the problem. Graphs of phase velocity versus wave number have been presented. [ABSTRACT FROM AUTHOR]

In this work, the effect of initial stress and oblique loading on plane waves in thermoelastic media will be investigated in the context of three-phase-lag theory. The entire elastic medium rotates at a uniform angular velocity. The problem is solved numerically by normal modal analysis. Plot and analyze the numerical results for temperature, displacement components, and stress. Graphical results show that the effects of phase delay, tilt angle, and initial stress parameters are evident. Variations in these quantities are plotted in the three-phase hysteresis model (3PHL) and the type III Green and Naghdi theory (G-N III) for insulated boundaries to show the effect of initial stress and angle of inclination in the medium. [ABSTRACT FROM AUTHOR]

The present study deals with axisymmetric circular/annular disks made of three-phase multi-scale hybrid laminated nanocomposite under distributed static loadings. The structure is placed on Winkler-Pasternak substrate with friction effects. Initial stress is also considered in the composite structure. The mathematical model is prepared using three-dimensional elasticity theory (3D-elasticity theory). The derived differential equations are solved by employing the semi-analytical method of state-space-based differential quadrature method (SS-DQM) to obtain the stress and displacement fields of the composite structure. In the numerical analyses, a comprehensive parametric study is performed to observe the effects of some geometrical and physical parameters on bending characteristics of composite circular/annular disks. [ABSTRACT FROM AUTHOR]

Shot peen forming is a process widely used to shape aircraft components such as wing skins, yet its fundamental working is still crudely understood. It is understood that a light conventional peen forming treatment applied uniformly over an initially flat plate will induce isotropic in‐plane stretching of the surface layer and will thus lead to a panel curving with identical curvatures in all directions. However, [1] made the startling observation that uniformly peen formed aluminium plates of different aspect ratios all bent along their laminating direction irrespective of the peening direction. This experimental result is counterintuitive because the residual stresses due to the lamination process are 1 order to 2 orders of magnitude smaller than those induced by the shot peen forming treatment. In the present study, we apply the eigenstrain theory to estimate the effect of the different sources of anisotropy on uniformly peen formed aluminium plates. Potential sources of anisotropy included the plastic anisotropy of rolled aluminium, nonequibiaxial initial stresses that redistribute when their equilibrium is disturbed by peening, the geometry of the specimens and externally applied prestress. For the alloy and peening conditions considered, we show that plastic anisotropy had no discernible influence on the resulting shape of the peen formed specimens. Initial residual stresses, on the other hand, caused slightly larger bending loads in the rolling direction of the alloy. Although the magnitude of these loads was approximately 30 times smaller than peening‐induced loads, it was sufficient to overcome the geometric preference for rectangular sheets to bend along their long side and cause all unconstrained specimens to bend along the rolling direction instead. Our analysis highlights the importance of the history of the material that is being peened. Residual stresses already present in the part before peening must be considered to ensure good simulation predictions. [ABSTRACT FROM AUTHOR]

In this work, an analysis of the propagation of horizontally polarized magnetoelastic shear waves at a loosely bonded interface between two fiber-reinforced (FRC) media is performed. The assumption is that the upper layer is a heterogeneous FRC medium with initial stress, while the lower layer is an FRC half-space subject to gravity. A closed-form expression of the dispersion equation has been derived using Whittaker's function and its asymptotic expansion for both exponential and linear types of heterogeneous cases. The obtained dispersion equation matches well with previously existing results and the classical Love wave equation. In both cases, it was found that the magnetoelastic coupling parameters, horizontal compressive initial stresses, loosely bound, and Biot's gravity parameter of the layered structure all have a favoring effect on the phase velocity. It was also observed that in the linear heterogeneous case, the magnetoelastic coupling parameter has a detrimental influence on the speed of shear wave propagation, while in the exponential heterogeneous situation, it has a beneficial impact. The findings of this study can be used to improve analysis in the fields of geotechnical engineering and civil engineering. This study examines the characteristic behavior of horizontally polarized magnetoelastic shear wave propagation in an inhomogeneous fiber reinforced layer overlaying a fiber-reinforced half-space in the presence of initial stress and gravity. Reinforced materials are now one of the fundamental necessities of building projects of any significant magnitude. In addition, it is crucial to consider the impact of loose bonding at the common interface between the layer and the half-space while building the sensors to improve their efficacy and ultimately achieve high performance. This work is relevant to geotechnical and civil engineering applications and is innovative. Examining the effect of various nondimensional parameters' responses to wave motion is of great interest to researchers due to the immense practical and economic potential of composite structures made from such materials. The present article may have numerous applications in the disciplines of space exploration, aviation, construction, geophysics, geomechanics, and so on. [ABSTRACT FROM AUTHOR]

The present paper is to investigate the effect of initial stress and inclined Load on the plane waves in a linearly micropolar thermoelastic medium possessing cubic symmetry in the context of the three-phase-lag-theory. The problem has been solved numerically using the normal mode analysis. Numerical results for the temperature, displacement components, the stresses and microrotation are represented graphically and the results are analyzed. The graphical results indicate that the effect of phase lags, angle of inclination and the initial stress parameter on the plane waves in the micropolar thermoelastic medium are pronounced. The variations of these quantities have been depicted graphically in the three-phase-lag model (3PHL), Lord-Shulman (L-S) theory and Green and Naghdi theory for type III (G-N: III) for an insulated boundary to show the effect of the initial stress and angle of inclination in the medium. [ABSTRACT FROM AUTHOR]

The present study aims to investigate the propagation of transverse waves in an inhomogeneous, anisotropic, thinly layered laminated solid medium. Transverse waves are essential tools for understanding the Earth's interior. The Earth is a dynamic, pre-stressed material due to factors like external forces and ongoing creep processes. Natural stresses are still prevalent within the Earth's layers, and these can have a substantial impact on both the medium's stability and the propagation of elastic waves caused by seismic events or explosions. A more precise assessment can be achieved by accounting for the bending rigidity of the laminated structures. This study delves into the repercussions of thermal stress and couple stress on the transverse wave propagation within a layered medium characterized by nonlocal anisotropic properties. Through the incorporation of linear inhomogeneities, a frequency equation is derived, shedding light on the determination of phase velocity for these waves. Specific cases are meticulously examined to provide further clarity on the underlying phenomenon. Extensive numerical simulations are executed, encompassing a wide range of parameter values, including the anisotropic factor, thermal stress parameter, initial stress parameter, nonlocal parameter, and couple stress parameter. The utilization of MATLAB software aids in the visual representation, effectively accentuating the notable impact of these parameters. The graphical representation underscores the significant role played by these factors in the investigated phenomenon, contributing valuable insights into the understanding of wave propagation in intricate geological materials. [ABSTRACT FROM AUTHOR]

Channel steel-reinforced brick column technology has gained significant popularity in rural China due to its convenience and cost effectiveness. However, current research on channel steel reinforcement is sparse, and engineering applications often rely solely on construction experience. This reliance leads to significant construction errors, inconsistent reinforcement effects, and, in some cases, tragedies such as the collapse of Changsha’s “4.29” self-built houses. Therefore, in this paper, experimental and simulation studies on brick columns reinforced with external channel steel were conducted, and the results show that channel steel reinforcement can significantly enhance the axial load capacity of brick columns. However, increased initial stress levels and height-to-thickness ratios substantially reduce the reinforcement effect. Under axial pressure, the outer channel steel fails mainly through bending and buckling instability. Still, due to its good ductility, its failure occurs later than the brick column after being restrained by sufficient wall screws. Based on the experimental and simulation results, a method for calculating the axial compressive bearing capacity of the reinforced column is proposed, providing theoretical support and engineering guidance for applying this reinforcement method.

Present geophysical model analyzes the propagation characteristics of torsional wave in an inhomogeneous viscoelastic fiber‐reinforced layer sandwiched between superior porous layer and transversely isotropic piezoelectric subspace with imperfect interfaces. Porous layer and intermediate reinforced layer are endowed with initial stress and corrugated interfaces, whereas the lower piezoelectric half space possesses rectangular cavity at the welded contact. Earth's adjacent layers near mountainous region often endowed with initial stresses resemble the present geological setup. The material properties of intermediate layer are considered to be varying exponentially. Particular cases have been deduced for electrically open and short condition for validation with the standard Love wave expressions. Effects of the relevant parameters on resultant torsional velocity have been explored through numerical simulation and depicted for electrically short and open conditions. Findings of present model may be utilized in the field of signal testing, sensors design, seismic acoustic wave (SAW) devices, and geophysical application concerned with torsional wave based on non‐destructive evaluation. [ABSTRACT FROM AUTHOR]

• Velocity profile of Circumferential SH waves in concentric cylinders have been investigated. • Cylinders are composed of self-fibre-reinforced, and piezo-magnetic-electric materials. • Phase velocity of ESMO case is found to have higher or equal magnitude compared to EOMS case. • Mechanical imperfect interface parameter has highest impact on the phase velocity. • Initial stress and radii of the cylinder bears a significant impact in altering the velocity of the wave. The present study fundamentally focuses on analyzing the limitations and transference of circumferential shear horizontal (CSH) waves in a four-layered compounded cylinder. The geometrical structure consists of cylinders of infinite length composed of self-reinforced (SR), fibre-reinforced (FR), piezo-magnetic (PM), and piezo-electric(PE) materials. In order to make the structure sensitive to the application pertaining to sensors and actuators, the PM and PE cylinders have been categorically placed in the outer part of the geometry. Whereas in order to provide stiffness and stability to the structure, the inner part consists of SR and FR materials. The common boundary between each of the cylinders has been essentially considered as imperfectly bounded. At the interface of PE and PM media, mechanical, electrical, magnetic, and inter-coupled types of imperfections have been exhibited. The closed-form of dispersion relation has been deduced for two contrast cases i.e. electrically open magnetically short (EOMS) and electrically short and magnetically open (ESMO) circuit conditions. Dispersion curves have been plotted to illustrate the salient features of parameters like normalized imperfect interface parameters, initial stresses, and radii of the concentric cylinders. The comparative effect of each one of these parameters on the phase velocity of the wave has been enlisted and marked individually. Every graph has been presented with two successive modes for a comprehensive understanding. This theoretical study may be implemented to improvise the performance of surface acoustic wave (SAW) sensors, actuators, and Piezo-cables in the form of Piezo-polymer sensors consisting of piezo-electric quartz, piezo-composite concentric cylinders, and coaxial piezo-cables. [ABSTRACT FROM AUTHOR]

Configuration-controllable metamaterials are a kind of metamaterials whose bandgaps can be effectively adjusted through configuration control, but the configuration changes also produce initial stress. In this paper, the distribution of the initial stress of the configuration-controllable metamaterial under axial displacement and the influence of initial stress on the band gap characteristics of the structure were analyzed using numerical and experimental methods. The results show that initial stress has a significant influence on the bandgap characteristics, and the position and width of the bandgap change with the magnitude of the initial stress. The bandgap distribution of the structure after considering the initial stress is more consistent with the reported experimental results. The influence of initial stress on bandgap cannot be ignored. When the compressive loading displacement is 10 mm, the frequency range of the first bandgap is 262 Hz–310 Hz and that of the second bandgap is 394 Hz–405 Hz. And the frequency range of the first and second bandgaps will be converted into 254 Hz–291 Hz and 391 Hz–400 Hz when considering initial stress. The initial stress generated by compression deformation reduces the frequency of the structural bandgap. The beginning and ending frequencies of the first bandgap will move toward low frequencies, and the first bandgap will close when the compression displacement reaches 30 mm. The initial stress generated by tensile deformation increases the frequency of the structural bandgap. The beginning and ending frequencies of the first bandgap move toward high frequencies, and the bandgap will close when the tensile displacement is 30 mm. [ABSTRACT FROM AUTHOR]

The current work examines shear wave propagation in inhomogeneous functionally graded orthotropic media (FGOM) with imperfect contacts. The intermediate stratum is assumed to be viscous FGOM, while the upper and lower FGOMs have been endowed with initial stress. Closed-form displacement fields have been derived for both the layers and half space. The derivation process involves employing the interfacial stress-displacement continuity condition, which accounts for sliding and loosely bonded parameters, in conjunction with the requirement of a stress-free upper interface and a bounded lower half space. Special cases of previously published results in the literature were used to validate the analytical form of the dispersion relation. The study also includes a mathematical analysis of the dispersion equation as well as numerical computations for the presented geophysical model to characterize the impact of initially stressed parameters, inhomogeneity parameters, dissipation factor, and the effect of interface imperfectness on shear wave velocity. Notably, the study emphasizes the effect of sliding interface on the propagation of SH waves at the lower contact. The current finding adds to our understanding of shear wave propagation dynamics in elastic inhomogeneous functionally graded materials, which can help with earthquake engineering design and execution. [ABSTRACT FROM AUTHOR]

This research examined the propagation of the crack in an initially strained anisotropic magnetoelastic material due to SH-waves. For a concentrated load of constant intensity and constant loading, the stress intensity factor at the crack tip is calculated separately. The Wiener–Hopf method and the double Fourier integral transform were used to address the problem. Graphs have been used to show the emphatic impact of various influencing parameters on the stress intensity factor in an initially stressed magnetoelastic medium, including fracture speed, crack length, initial stress, anisotropic magnetoelastic coupling parameter, and the angle at which the wave passes through the magnetic field. Using the resulting expression of the stress intensity factor for the force of constant intensity, numerous exceptional cases have been determined. The results were presented using graphs created with Mathematica 7. [ABSTRACT FROM AUTHOR]

Propagating guided waves in a homogeneous, isotropic, prestressed, hyperelastic plate show nonlinear characteristics that depend on the state of initial prestress. These nonlinear phenomena include higher harmonic generation, occurring when Lamb wave modes of different frequencies ( ω a and ω b ) are allowed to mix within the material generating secondary waves at frequencies 2 ω a , 2 ω b and ω a ± ω b . Further, if prescribed internal-resonance conditions are satisfied, the amplitude of secondary waves increases in space, providing a response quantity which is dependent on prestress and easy to be observed. Using the finite element method, in this paper we investigate the time and space evolution of higher harmonics arising in one-way wave mixing. The influence of prestress on the response is elucidated, observing the nonlinear parameter β . It is further shown that the nonlinear ultrasonic technique called sideband peak count-index (SPC-I) can provide an effective monitoring tool for prestress. [ABSTRACT FROM AUTHOR]