Showing papers in "Multidiscipline Modeling in Materials and Structures in 2014"

Process modeling, joint-property characterization and construction of joint connectors for mechanical fastening by self-piercing riveting

Abstract: Purpose – The purpose of this paper is to propose a computational approach in order to help establish the effect of various self-piercing rivet (SPR) process and material parameters on the quality and the mechanical performance of the resulting SPR joints. Design/methodology/approach – Toward that end, a sequence of three distinct computational analyses is developed. These analyses include: (a) finite-element modeling and simulations of the SPR process; (b) determination of the mechanical properties of the resulting SPR joints through the use of three-dimensional, continuum finite-element-based numerical simulations of various mechanical tests performed on the SPR joints; and (c) determination, parameterization and validation of the constitutive relations for the simplified SPR connectors, using the results obtained in (b) and the available experimental results. The availability of such connectors is mandatory in large-scale computational analyses of whole-vehicle crash or even in simulations of vehicle c...

The influence of thermal loading due to laser pulse on generalized micropolar thermoelastic solid with comparison of different theories

Abstract: Purpose – The purpose of this paper is to introduce the coupled theory, Lord-Shulman theory with one relaxation time and Green-Lindsay theory with two relaxation times to study the influence of rotation on generalized micropolar thermoelasticity subject to thermal loading due to laser pulse. The bounding plane surface is heated by a non-Gaussian laser beam with pulse duration of 8 ps. Design/methodology/approach – The problem has been solved numerically by using the normal mode analysis. Findings – The thermal shock problem is studied to obtain the exact expressions for the displacement components, force stresses, temperature, couple stresses and micro-rotation. The distributions of the considered variables are illustrated graphically. Comparisons are made with the results predicted by three theories in the presence and absence of laser pulse and for different values of time. Originality/value – Generalized micropolar thermoelastic solid.

Plane wave propagation in an anisotropic dual-phase-lag thermoelastic diffusion medium

Abstract: Purpose – The purpose of this paper is to depict the effect of thermal and diffusion phase-lags on plane waves propagating in thermoelastic diffusion medium with different material symmetry. A generalized form of mass diffusion equation is introduced instead of classical Fick's diffusion theory by using two diffusion phase-lags, one phase-lag of diffusing mass flux vector, represents the delayed time required for the diffusion of the mass flux and the other phase-lag of chemical potential, represents the delayed time required for the establishment of the potential gradient. The basic equations for the anisotropic thermoelastic diffusion medium in the context of dual-phase-lag heat transfer (DPLT) and dual-phase-lag diffusion (DPLD) models are presented. The governing equations for transversely isotropic and isotropic case are also reduced. The different characteristics of waves like phase velocity, attenuation coefficient, specific loss and penetration depth are computed numerically. Numerically computed ...

Improved gas metal arc welding multi-physics process model and its application to MIL A46100 armor-grade steel butt-welds

Abstract: Purpose – The purpose of this paper is to develop multi-physics computational model for the conventional gas metal arc welding (GMAW) joining process has been improved with respect to its predictive capabilities regarding the spatial distribution of the mechanical properties (strength, in particular) within the weld. Design/methodology/approach – The improved GMAW process model is next applied to the case of butt-welding of MIL A46100 (a prototypical high-hardness armor-grade martensitic steel) workpieces using filler-metal electrodes made of the same material. A critical assessment is conducted of the basic foundation of the model, including its five modules, each dedicated to handling a specific aspect of the GMAW process, i.e.: first, electro-dynamics of the welding-gun; second, radiation/convection controlled heat transfer from the electric arc to the workpiece and mass transfer from the filler-metal consumable electrode to the weld; third, prediction of the temporal evolution and the spatial distribu...

All-atom Molecular-level Computational Simulations of Planar Longitudinal Shockwave Interactions with Polyurea, Soda-lime Glass and Polyurea/Glass Interfaces

Abstract: Purpose – The purpose of this paper is to study the mechanical response of polyurea, soda-lime glass (glass, for short), polyurea/glass/polyurea and glass/polyurea/glass sandwich structures under dynamic-loading conditions involving propagation of planar longitudinal shockwaves. Design/methodology/approach – The problem of shockwave generation, propagation and interaction with material boundaries is investigated using non-equilibrium molecular dynamics. The results obtained are used to construct basic shock Hugoniot relationships associated with the propagation of shockwaves through a homogeneous material (polyurea or glass, in the present case). The fidelity of these relations is established by comparing them with their experimental counterparts, and the observed differences are rationalized in terms of the microstructural changes experienced by the shockwave-swept material. The relationships are subsequently used to predict the outcome of the interactions of shockwaves with polyurea/glass or glass/polyu...

Multi-objective optimisation of CNC milling process using Grey-Taguchi method in machining of GFRP composites

Abstract: Purpose – In milling process the surface roughness and delamination are the most important performance characteristics, which are influenced by many factors like fibre orientation angle, helix angle, feed rate and spindle speed. The selection of these parameters at optimum level plays a vital role in getting minimum surface roughness and delamination factor. The purpose of this paper is to present multi-objective optimisation of Computer Numerical Control milling parameters using Grey-Taguchi method to get minimum surface roughness and delamination factor in machining of glass fibre reinforced plastics (GFRP) composites used in automotive, aircraft and manufacture of space ships. Design/methodology/approach – The experiments are designed and conducted based on Taguchi's L27 orthogonal array by taking fibre orientation angle, helix angle, feed rate and spindle speed at three levels and responses are surface roughness and delamination factor. Taguchi's signal-to-noise (S/N) ratio are determined based on the...

Analysis of Steel-With-Composite Material Substitution in Military Vehicle Hull Floors Subjected to Shallow-Buried Landmine-Detonation Loads

Abstract: Purpose – The purpose of this paper is to address the problem of substitution of steel with fiber-reinforced polymer-matrix composite in military-vehicle hull-floors, and identifies and quantifies the associated main benefits and shortcomings. Design/methodology/approach – The problem is investigated using a combined finite-element/discrete-particle computational analysis. Within this analysis, soil (in which a landmine is buried), gaseous detonation products and air are modeled as assemblies of discrete, interacting particles while the hull-floor is treated as a Lagrangian-type continuum structure. Considerable effort has been invested in deriving the discrete-material properties from the available experimental data. Special attention has been given to the derivation of the contact properties since these, in the cases involving discrete particles, contain a majority of the information pertaining to the constitutive response of the associated materials. The potential ramifications associated with the afor...

Effect of static axial compression on the natural frequencies of helical springs

Abstract: Purpose – The purpose of this paper is to address the practically important problem of the load dependence of transverse vibrations for helical springs. At the beginning, the author develops the equations for transverse vibrations of the axially loaded helical springs. The method is based on the concept of an equivalent column. Second, the author reveals the effect of axial load on the fundamental frequency of transverse vibrations and derive the explicit formulas for this frequency. The fundamental natural frequency of the transverse vibrations of the spring depends on the variable length of the spring. The reduction of frequency with the load is demonstrated. Finally, when the frequency nullifies, the side buckling spring occurs. Design/methodology/approach – Helical springs constitute an integral part of many mechanical systems. A coil spring is a special form of spatially curved column. The center of each cross-section is located on a helix. The helix is a curve that winds around with a constant slope...

Analysis of Fe78Si9B13 (%at.) ribbons of noncommercial scrap materials produced by melt spinning equipment

Abstract: Purpose – The purpose of this paper is to present a ribbons production route of composition Fe78Si9B13 (%at.) using low cost noncommercial scrap materials to obtain usable magnetic cores by melt spinning technique and their characterization. This way, these may compete with the materials produced by conventional casting processes. Design/methodology/approach – The methodology is to design a master alloy with scrap different starting compositions, to which Fe is added to get the desired atomic ratio of components. With this starting alloy, using the method of melt spinning, in its variant of chill block melt spinning, are achieved amorphous ribbons with desired soft magnetic behavior. Then these ribbons are thermally treated for achieve nanocrystalline structures to improve the performance in the magnetic cores. Findings – The result of this paper shows that it is possible to recycle scrap materials, and re-used efficiently as components essential in part of electrical components. This way, these may compe...

Mechanical behaviour and identification of damage by acoustic emission of smart composites

Abstract: Purpose – The smaller sizes of current electronic devices suggest the feasibility of creating a smart composite structure using piezoelectric implant to monitor in-situ and in-service conditions the life of civil and aerospace structures. Piezoelectric (lead zirconate-titanate (PZT)) sensors embedded within laminates composites represent a new branch of engineering with the potential to greatly enhance the confidence and use of these materials. The paper aims to discuss these issues. Design/methodology/approach – This study presents a health monitoring of laminates composites materials incorporating by piezoelectric (PZT) implant using acoustic emission (AE) technique. A series of specimens of laminate composite with and without embedded piezoelectric were tested in three-point bending tests in static and creep loading while continuously monitoring the response by the AE technique. The AE signals were analysed using the classification k-means method in order to identify the different damages and to follow...

PID control of torque during drilling in GFRP laminates

Abstract: Purpose – Damage induced during drilling of polymer matrix composites depends upon torque during drilling. Modeling of torque with feed rate and its control becomes imminent for damage free drilling of composite laminates. Therefore, the purpose of this paper is to construct a transfer function between drilling torque and feed rate based upon experiments. Thereafter, the torque is controlled by using PID controller. Design/methodology/approach – This paper presents step-by-step procedure to capture complex drilling dynamics of polymer matrix composites in a mathematical model. A glass fiber reinforced plastic (GFRP) composite laminate is drilled at constant feed rate during experimentation. The corresponding time response of torque is recorded. First order, second order and third order transfer functions between torque and feed rate are identified using system identification toolbox of Matlab®. These transfer functions are then converted into state-space models. Experimental verification is performed on G...

Effect of heat and mass transfer and rotation on peristaltic flow through a porous medium with compliant walls

Abstract: Purpose – The purpose of this paper is to investigate the peristaltic flow of an incompressible Newtonian fluid in a channel with compliant walls. The effects of rotation and heat and mass transfer are also taken into account. The governing equations of two dimensional fluid have been simplified under long wavelength and low Reynolds number approximation. An exact solutions is presented for the stream function, temperature, concentration field, velocity and heat transfer coefficient. Design/methodology/approach – The effect of the concentration distribution, heat and mass transfer and rotation on the wave frame are analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of rotation and heat and mass transfer. Findings – The results indicate that the effect of the permeability and rotation are very pronounced in the phenomena. Originality/value – The objective ...

Thermo elastic-plastic transition of transversely isotropic thick-walled circular cylinder under internal and external pressure

Abstract: Purpose – The purpose of this paper is to provide the guidance on a design and integrity evaluation of a cylinder under pressure, for which stress analysis has been done for transversely isotropic thick-walled circular cylinder under internal and external pressure with thermal effects Design/methodology/approach – Transition theory has been used to evaluate plastic stresses based on the concept of generalized principal Lebesgue strain measure which simplifies the constitutive equations and helps to achieve better agreement between the theoretical and experimental results Findings – It can be concluded that circular cylinder with thermal effects under internal and external pressure made of isotropic material (steel) is on the safer side of the design as compared to the cylinder made of transversely isotropic material (ie magnesium and beryl) because percentage increase in effective pressure required for initial yielding to become fully plastic is high for isotropic material (steel) as compared to trans

The flutter of truncated conical shell subjected to internal supersonic air flow

Abstract: Purpose – The purpose of this paper is to propose a new approach to determine the aeroelastic instability of truncated conical shells. In the proposed approach the governing equation of flutter for a truncated conical shell is established using Love's thin shell theory and the quasi-steady first-order piston theory. Design/methodology/approach – The derivatives in both the governing equations and the boundary conditions are discretized with the differential quadrature method, and the critical flutter chamber pressure is obtained by eigenvalue analysis. Findings – The influence of the shell geometry parameters, such as semi-cone angle, radius-thickness ratio and length-radius ratio, on the critical flutter chamber pressure is studied. Results are also presented to indicate the stabilizing effects of aerodynamic damping and the destabilizing effects of the curvature correction term of piston theory on flutter of truncated conical shell. Originality/value – The present approach is an efficient method for the...

Influence of disk brake friction on the dynamic behaviour of a directly coupled spur gear transmission

Abstract: Purpose – The purpose of this paper is to study the influence of friction phenomenon generated by a disc brake on the dynamic behaviour of a one-stage spur gear. Design/methodology/approach – A theoretical model is proposed and is based on both theories of Coulomb and Dahl in order to analyse the influence of disc brake friction phenomenon on the dynamic behaviour of one-stage spur gear transmission. Findings – The influence of brake friction on the dynamic behaviour of the transmission is investigated using the proposed model and leads to observe higher vibration levels when the braking is occurring as well as the emergence of significant efforts at the gear teeth. Originality/value – A new numerical model based on the implicit numerical integration technique of Newmark coupled with Newton-Raphson method is proposed to study the influence of friction phenomenon of a disc brake on the dynamic behaviour of one-stage spur gear.

A modified Preisach model and its inversion for hysteresis compensation in piezoelectric actuators

Abstract: Purpose – Piezoelectric actuators (PEAs) exhibit hysteresis nonlinearity in open-loop operation, which may lead to unwanted inaccuracy and limit system performance. Classical Preisach model is widely used for representing hysteresis but it requires a large number of first-order reversal curves to ensure the model accuracy. All the curves may not be obtained due to the limitations of experimental conditions, and the detachment between the major and minor loops is not taken into account. The purpose of this paper is to propose a modified Preisach model that requires relatively few measurements and that describes the detachment, and then to implement the inverse of the modified model for compensation in PEAs. Design/methodology/approach – The classical Preisach model is modified by adding a derivative term in parallel. The derivative gain is adjusted to an appropriate value so that the measured and predicted hysteresis loops are in good agreement. Subsequently, the new inverse model is similarly implemented ...

Optimal control during drilling in GFRP composite laminates

Abstract: Purpose – Damage due to delamination is an important issue during drilling in polymer-matrix composites (PMCs). It depends on thrust force and torque which are functions of feed rate. Transfer function of thrust force with feed rate and torque with feed rate is constructed through experiments. These transfer functions are then combined in state-space to formulate a sixth-order model. Then thrust force and torque are controlled by using optimal controller. The paper aims to discuss these issues. Design/methodology/approach – A glass fiber reinforced plastic composite is drilled at constant feed rate during experimentation. The corresponding time response of thrust force and torque is recorded. Third-order transfer functions of thrust force with feed rate and torque with feed rate are identified using system identification toolbox of Matlab®. These transfer functions are then converted into sixth-order combined state-space model. Optimal controller is then designed to track given reference trajectories of t...

Artificial neural network simulation and particle swarm optimisation of friction welding parameters of 904L superaustenitic stainless steel

Abstract: Purpose – Friction welding (FW) is a solid state joining process. Super austenitic stainless steel is the preferable material for high corrosion resistance requirements. These steels are relatively cheaper than austenitic stainless steel and it is expensive than nickel base super alloys for such applications. The purpose of this paper is to deal with the optimization of the FW parameters of super austenitic stainless steel using artificial neural network (ANN) simulation and particle swarm optimization (PSO). Design/methodology/approach – The FW experiments were conducted based on Taguchi L-18 orthogonal array. In FW, rotational speed, friction pressure, upsetting pressure and burn-off length are the important parameters which determine the strength of the weld joints. The FW trials were carried out on a FW machine and the welding time was recorded for each welding trial from the computerized control unit of the welding machine. The left partially deformed zone (L.PDZ) and right partially deformed zone (R...

Real time algorithm implemented in Altera's FPGA for a newly designed mobile robot: Autonomous navigation and parallel parking

Abstract: Purpose – The purpose of this paper is to propose a generic platform for a robotic mobile system, seeking to obtain a support tool for under-graduation and graduation activities Another objective was to gather knowledge in the mobile robotic area in order to provide practical solutions for industrial problems Design/methodology/approach – The proposed new integrated platform would serve as didactic material for many disciplines, shown to be an ideal platform to teach DC motor drives, stepper motor and motion-control systems To reach this objective, the ability of the robot to plan its motion autonomously is of vital importance The control of a mobile robot in dynamic and unstructured environments typically requires efficient processing of data/information to ensure precise navigation and many other applications Path planning is also one common method of auto-navigation After the computation of the shortest path, mobile robot can navigate safely and without occlusion Findings – The developed platfor

Heat transfer of convective MHD viscoelastic fluid along a moving inclined plate with power law surface temperature using finite element method

Abstract: Purpose – The purpose of this paper is to deal with the study of free convection magnetohydrodynamic (MHD) boundary layer flow of an incompressible viscoelastic fluid along an inclined moving plate and heat transfer characteristics with prescribed quadratic power-law surface temperature. Design/methodology/approach – The governing partial differential equations are transformed into non-dimensional, non-linear coupled ordinary differential equations which are solved numerically by robust Galerkin finite element method. Findings – Numerical results for the dimensionless velocity and temperature profiles are displayed graphically for various physical parameters such as viscoelasticity, Prandtl number, angle of inclination parameter, magnetic and buoyancy parameter. The local Nusselt number is found to be the decreasing function of magnetic field parameter whereas it increases with increasing values of Prandtl number, viscoelastic parameter and buoyancy parameter. Practical implications – The present problem ...

Multi-response optimization of tribological characteristics of aluminum MMCs using PCA

Abstract: Purpose – Since, wear is the one of the most commonly encountered industrial problems leading to frequent replacement of components there is a need to develop metal matrix composites (MMCs) for achieving better wear properties. The purpose of this paper is to fabricate aluminum MMCs to improve the dry sliding wear characteristics. An effective multi-response optimization approach called the principal component analysis (PCA) was used to identify the sets of optimal parameters in dry sliding wear process. Design/methodology/approach – The present work investigates the dry sliding wear behavior of graphite reinforced aluminum composites produced by the molten metal mixing method by means of a pin-on-disc type wear set up. Dry sliding wear tests were carried on graphite reinforced MMCs and its matrix alloy sliding against a steel counter face. Different contact stress, reinforcement percentage, sliding distance and sliding velocity were selected as the control variables and the response selected was wear vol...

Relaxation and creep in twist and flexure

Abstract: Purpose – The purpose of this paper is to derive the exact analytical expressions for torsion and bending creep of rods with the Norton-Bailey, Garofalo and Naumenko-Altenbach-Gorash constitutive models. These simple constitutive models, for example, the time- and strain-hardening constitutive equations, were based on adaptations for time-varying stress of equally simple models for the secondary creep stage from constant load/stress uniaxial tests where minimum creep rate is constant. The analytical solution is studied for Norton-Bailey and Garofalo laws in uniaxial states of stress. Design/methodology/approach – The creep component of strain rate is defined by material-specific creep law. In this paper the authors adopt, following the common procedure Betten, an isotropic stress function. The paper derives the expressions for strain rate for uniaxial and shear stress states for the definite representations of stress function. First, in this paper the authors investigate the creep for the total deformatio...

Reflection of plane waves from a thermo-microstretch elastic solid with temperature dependent elastic properties

Abstract: Purpose – The purpose of this paper is to study the reflection of a plane harmonic wave at the interface of thermo-microstretch elastic half space. The modulus of elasticity is taken as a linear function of reference temperature. The formulation is applied to generalized thermoelasticity theories, the Lord-Shulman and Green-Lindsay theories, as well as the classical dynamical coupled theory. Using potential function, the governing equations reduce to ten-order differential equation. Design/methodology/approach – Coefficient ratios of reflection of different waves with the angle of incidence are obtained using continuous boundary conditions. By numerical calculations, the variation of coefficient ratios of reflection with the angle of incidence is illustrated graphically for magnesium crystal micropolar material under three theories. Findings – The effect of different temperature-dependent constants and frequency on the coefficient ratios of reflection is illustrated graphically in context of Lord-Shulman ...

Damage alarming analysis for ancient wood structures based on wavelet packet energy spectrum

Abstract: Purpose – The purpose of this paper is to establish the damage alarming indexes for ancient wood structures and study the damage sensitivity and noise robustness of these indexes under random excitation. Design/methodology/approach – Xi’an Bell Tower is taken as a case in this paper to simulate the damage of ancient wood structures through finite element (FE) simulation and determine the satisfactory damage alarming indexes with wavelet packet energy spectrum. Findings – The results of this paper show that: 1) the damage alarming indexes can effectively identify the damage of ancient wood structures, each index with a different damage sensitivity; 2) the energy ratio deviation is greater than the energy ratio variance and is close to the maximum variation of energy ratio; 3) the energy ratio deviation has a better alarming effect than the energy ratio variance during the initial period of the damage. With the accumulation of the damage, the energy ratio variance outperforms the energy ratio deviation; 4) ...

Experimental verification of detection and prediction of multiple cracks by vibrations, FEM and ANN

Abstract: Purpose – The purpose of this paper is to address the determination of crack location and depth of multiple transverse cracks by monitoring natural frequency and its prediction using Artificial Neural Networks (ANN). An alternative to the existing NDTs is suggested. Design/methodology/approach – Modal analysis is performed to extract the natural frequency. Analysis is performed for two cases of cracks. In first case, both cracks are perpendicular to axis. In second case, both cracks are inclined to vertical plane and also inclined with each other. Finite element method (FEM) is performed using ANSYSTM software which is theoretical basis. Experimentation is performed using Fast Fourier Transform (FFT) analyzer on simply supported stepped rotor shaft and cantilever circular beam with two cracks each. Findings – The results of FEM and experimentation are validated and are in good agreement. The error in crack detection by FEM is in the range of 3-15 percent while 5-20 percent by experimentation. The database...

Continuum description of damage and failure of composite laminates based on viscous regularization

Abstract: Purpose – The purpose of the paper is to improve the calculability of a continuum damage failure model of composite laminates based on Tsai-Wu criteria. Design/methodology/approach – A technique based on viscous regularization, a characteristic element length and fracture energies of fiber and matrix are used in the model. Findings – The calculability of the material model is improved. The modified model can predict the behavior of composite structure better. Originality/value – The convergence problem and the mesh softening problem are main concern in the calculability of numerical model. In order to improve the convergence, a technique based on viscous regularization of damage variable is used. Meanwhile, characteristic element length and fracture energies of fiber and matrix are added into the damage constitutive equation to reduce the mesh sensitivity of numerical results. Finally, a laminated structure with damages is implemented using a User Material Subroutine in ABAQUS/Standard. Mesh sensitivity a...

Modeling of current-voltage characteristic of the intergranular barrier in metal oxide varistor ceramics

Abstract: Purpose – The purpose of this paper is to develop a generalized model of the nonlinear conductivity of varistor ceramic suitable for solving problems of prediction and control of ceramic nonlinearity, stability of varistor properties. Design/methodology/approach – The modeling of current-voltage characteristic of the intergranular barrier in metal oxide varistor ceramics is based on the development of the algorithm. It includes all the known mechanisms of electrotransfer in a wide range of voltages and currents of the current-voltage characteristics, and also takes into account the deviation of the barrier form the Schottky barrier. Findings – The models of double Schottky barrier and double barrier of arbitrary form, as well as the algorithms for calculating the current-voltage characteristics of a single intergranular potential barrier and a separate “microvaristor” with the use of the most well-established understanding of the main mechanisms of electrical are developed. The results of current-voltage ...

Response of harmonic sources in couple stress thermoelastic medium with state space approach

Abstract: Purpose – The purpose of this paper is to investigate the two-dimensional problem in couple stress thermoelastic medium for a half space is established and state space approach has been applied to solve the problem. Design/methodology/approach – Normal mode analysis is used to obtain the exact expressions for normal stress, tangential stress and couple stress. Numerical calculation is prepared for these quantities and depicted graphically for a special model. Findings – The expressions for normal stress, tangential stress and couple stress are obtained numerically and depicted graphically to see the couple stress effect. Originality/value – It is found that couple stress effect decrease the value of normal stress components for circular frequency equal to 0.5 for small values of the wave number and then increases whereas the values of normal stress components decrease first and then increase monotonically for circular frequency equal to 0.1 when the force is applied in normal direction and the values of t...

FE modeling of creep in linear and non-linear FGM cylinder under internal pressure

Abstract: Purpose – The purpose of this paper is to investigate creep in an internally pressurized thick-walled, closed ends cylinder made of functionally graded composite, having linear and non-linear distribution of reinforcement, using finite element (FE) analysis. Design/methodology/approach – FE-based Abaqus software is used to investigate creep behavior of a functionally graded cylinder. The cylinder is made of composite containing linear and non-linearly varying distributions of reinforcement along the radius. The creep behavior has been described by Norton's power law. The creep stresses and strains have been estimated in linear and non-linear functionally graded materials (FGM) cylinders and compared with those estimated for a similar composite cylinder but having uniform distribution of reinforcement. Findings – The radial stress in the composite cylinder is observed to decreases over the entire radius upon imposing linear or non-linear reinforcement gradients. However, the tangential stress in the cylind...

Stress wave analysis of thermo-piezoelectric solid bar of polygonal cross-sections immersed in fluid

Abstract: Purpose – The purpose of this paper is to study the problem of wave propagation in an infinite, homogeneous, transversely isotropic thermo-piezoelectric solid bar of polygonal (triangle, square, pentagon and hexagon) cross-section immersed in fluid is using Fourier expansion collocation method, with in the frame work of linearized, three-dimensional theory of thermo-piezoelectricity. Design/methodology/approach – A mathematical model is developed to study the wave propagation in an infinite, homogeneous, transversely isotropic thermo-piezoelectric solid bar of polygonal cross-sections immersed in fluid is studied using the three-dimensional theory of elasticity. Three displacement potential functions are introduced, to uncouple the equations of motion and the heat and electric conductions. The frequency equations are obtained for longitudinal and flexural (symmetric and antisymmetric) modes of vibration and are studied numerically for triangular, square, pentagonal and hexagonal cross-sectional bar immers...