Search

With the high precision requirements and the trend of large-scale composite parts, the development of composite molds is imminent. The short carbon fiber (SCF) composite mold is mainly prepared by the technological process flow of composite sheet injection, the bonding of composite plates, and machining. However, the current process optimization method has not matured adequately, and there are still many shortcomings, for example, low precision and high cost. In this paper, the optimization method of SCF/polyetherimide (PEI) composite molds is proposed. Many experiments have been conducted, and the results show that the coefficient of thermal expansion of composite samples can be effectively reduced and the mechanical properties can be improved by optimizing the SCF weight ratio and carbon fiber length. The bonding strength of composite joints in a high-temperature environment can be improved by optimizing the bonding process parameters and modification by carbon nanotubes. Based on the above optimization method, the SCF/PEI composite mold is prepared, and the C-shaped beam composite part is fabricated by using this mold. Compared with the part made by aluminum mold, the shape accuracy of the C-shaped beam composite part is proven high through digital measurement technology. [ABSTRACT FROM AUTHOR]

Composite laminates have become increasingly popular in industries like aerospace and shipbuilding. In practical applications, the creation of notches in composite laminates is often necessary to enable assembly and modifications. This rise in the use of notched composite laminates highlights the need for reliable methods to predict potential failures in these components. With these predictions, the safety and reliability of composite structures can be ensured by preventing catastrophic failures. The present paper investigates the use of the Virtual Isotropic Material Concept (VIMC) combined with the Finite Fracture Mechanics (FFM) criterion to predict the Last Ply Failure (LPF) load in keyhole notched composite laminates and under mode I loading conditions. Experimental tests were conducted to measure the LPF load of E-glass/Epoxy keyhole notched specimens, and the results were compared with the predicted results using the VIMC-FFM criterion. The paper also derives an expression for the Stress Intensity Factor (SIF) function for a crack that emanates from the keyhole notch tip under mode I loading conditions. The derived equation matches very well with numerical data and have a mean absolute error about 2% in the studied domain. The study shows that the VIMC-FFM criterion predicts the LPF load of keyhole notched composite laminates with acceptable accuracy and in a simple and low-cost manner. [ABSTRACT FROM AUTHOR]

A large number of experiments show that composite materials usually show different modulus properties in tension and compression (bi-modulus). However, for actual composite engineering structures, especially complex models, the numerical simulation calculation is usually based on a single modulus. In order to consider the different modulus characteristics of composite materials in tension and compression, researchers put forward simplified constitutive models of dual-modulus materials. However, these constitutive models have not been verified by a large number of experiments, especially by complex models. In this paper, the GWFMM model is simplified and used to analyze complex structures with different modulus in tension and compression. The experimental results of stiffened plate show that the improved GWFMM model can be used to analyze different modulus of tension and compression of complex stiffened structures. In addition, the influence of elastic modulus ratio in tension and compression under different experimental load conditions is further explored, and the influence law of bending and torsion on structures with bi-modulus is discussed. The relevant conclusions provide reference for the design and optimization of full-scale composite structures in marine engineering. [ABSTRACT FROM AUTHOR]

In this paper, a novel statistical vibration-based damage detection method is developed considering uncertainties in measured resonance frequencies. The proposed method is based on the application of resonance frequencies as the most accurate and easiest measurable vibration feature. For proof of efficiency of the proposed method, case studies were undertaken using two identical composite plates, one delaminated and the other pristine. In this respect, the frequency response functions (FRFs) were measured and used as the main input to the Resonance Detection Algorithm as the proposed method. Applying these FRFs to a Resonance Detector Function can determine the resonant frequencies and their statistical distribution. Through the statistical distributions of the corresponding resonant frequencies, their reliability of detecting damage has been obtained via the beta distribution. By observing the damage detection reliability of the two sets of corresponding resonant frequencies, it has been determined that the changes in natural frequencies are due to structural changes and not random errors through measurement. [ABSTRACT FROM AUTHOR]

In this paper, a research on theoretical analysis and finite element simulation of the damping sandwich composite plate with fixed support condition is carried out, and the dynamic characteristics of composite plates are explored by modal experiments. The vibration equilibrium equation of damping sandwich composite plate with fixed support condition is derived by combining first-order shear deformation theory, variational principle, and Hamilton principle. A set of modal basis functions satisfying the fixed support condition are established. The analytical solution is obtained via Galerkin weighted residual theory. The influence of structural parameters on the free vibration characteristics of the sandwich composite plates is investigated based on the mutual verification of theoretical calculation, numerical simulation, and modal test results. When the damping layer (0.2 mm) is located on the surface of the skin (2 mm), the first-order mode frequency and first-order loss factor are 196.66 Hz and 0.01, respectively. When the damping layer is in the neutral layer, the first-order mode frequency and first-order loss factor are 189.99 Hz and 0.14, respectively. Compared with the damping layer in the skin, the first-order mode frequency is reduced by 3.39%, while the first-order loss factor is 14 times higher. The results show that the damping performance of the structure is optimal when the damping layer is located in the neutral layer, and the structural stiffness is higher when the damping layer is close to the skin. The work provides theoretical guidance for the development and application of lightweight composite structures with large damping and high stiffness. [ABSTRACT FROM AUTHOR]

Smart laminated composite structures with piezoelectric patches are widely used in vibration control applications in several engineering fields. Precise mathematical models are required for the coupling of base structural and piezoelectric field variables. This paper presents the electro-structural analysis and optimization studies of piezoelectric energy harvester with laminated composite substrate plate subjected to base excitations. The coupled electro-mechanical equations are derived from recently proposed first-order shear deformation theory via the Hamilton's principle by considering hygrothermal effects. The coupled-field solution is obtained from Ritz-approximation and validated with three-dimensional finite element analysis. Effects of multiple piezoelectric patch topologies over the plate surface on the open-circuit voltage and displacement response are illustrated. Furthermore, the influences of piezoelectric-patch sizes, ply-orientation, size, and location of the tip mass are initially studied on the magnitude of output power and efficiency. An optimization study is conducted to identify the geometric and material variables for improvement of the harvester power output and efficiency. [ABSTRACT FROM AUTHOR]

In this paper, the free-edge effects which play an important role in the failure analysis of composite laminates are studied. Pure temperature change and its combination with biaxial tension are investigated for a composite plate with a centric circular hole that is adequately small in comparison to the dimension of the plate. Moreover, the laminate is assumed to be thin, the temperature change of all points of the plate is identical and the biaxial tensile load is applied far from the center of the hole. For this purpose, a semi-analytical method based on a two-dimensional thermoelastic boundary layer theory and a minimum potential energy principle is proposed. It is shown that the present method predicts the interlaminar peeling and shear stresses surrounding the hole with good agreement compared to the results obtained by FEM analysis. [ABSTRACT FROM AUTHOR]

In this paper, experiments and numerical simulations were used to study the mechanical properties of all-C/C composite hybrid bonded/bolted joints. Experiments were conducted to investigate the failure mechanisms, modes, and strengths of composite single-lap joints, namely, bolted joints with and without bonds. The results demonstrated that the failure mode of all-C/C composite mechanical joints was bolt shear failure, while the failure mode of the bonded joints was cohesive force failure. In hybrid bonded/bolted joints, cohesive force failure of the adhesive layer and bolt shear failure have both been noted. The C/C composite plates of all joints were not discovered to have any evident deterioration. The loaddisplacement curve of the hybrid joints was a double-peak curve, the first peak load corresponds to bonding failure, and the second peak load corresponds to bolt failure. For the failure process, mode, and strength of hybrid (bonded/bolted) joints, a 3D progressive damage finite element model was proposed. It is based on the nonlinear finite element code ABAQUS and Hashion failure criteria. The VUMAT subroutine compiled Hashion failure criteria to simulate the damage of fiber and matrix in the composite material. Furthermore, the adhesive layer's failure was simulated using the cohesive element. Comparing failure loads and failure modes to the outcomes of experiments served to validate the model. The gradual damage evolution process and failure mechanism of bonded and hybrid bonded/bolted joints were determined, as well as the mechanism by which the cohesive layer influences the mechanical properties of the hybrid bonded/bolted joints. On the mechanical characteristics of composite joints, the impacts of bolt diameter and adhesive layer modulus were investigated. [ABSTRACT FROM AUTHOR]

Numerical and experimental research programs have been carried out to investigate the effect of scaling on the tensile strength of notched composites. This paper presents a computational study of scaled open-hole tensile tests using the Discrete Ply Model (DPM) method. This finite element model is discrete, and only a small number of parameters are required from experimental characterization tests. Experimental and numerical strength values are compared here, and reveal that DPM simulations tend to slightly overestimate strength values, with an average discrepancy of 9.7%. However, DPM Results show that such modeling simulates both the reduction in strength when specimen size is increased for sublaminate level scaled specimens, where failure is fiber dominated, and the increase in strength when specimen size is increased for ply level scaled specimens, where failure is delamination dominated. In all cases, increasing the total thickness of the specimen leads to a decrease in strength and this effect is dominant over the effect of increasing hole diameter. As well as the variation in strength, three distinct failure mechanisms are observed: fiber failure with extensive matrix damage (pull-out failure), fiber failure with little or no matrix damage (brittle failure) and delamination failure. Comparisons with experiments demonstrate that tensile strengths, damage propagation scenarios and failure patterns are predicted with acceptable accuracy. [ABSTRACT FROM AUTHOR]

Out-of-plane waviness is one of the most common defects which degenerates the strength, stiffness, and fatigue life of hybrid glass–carbon fiber–reinforced polymer composites (FRPs). An accurate and high-speed non-destructive testing method is highly desired for large composite structures in industries. Ultrasonic phased array is a great candidate for such application. This paper applies the wavenumber algorithm to image the waviness in hybrid FRP plates which are a multi-layered medium. The central frequency of 5 MHZ is chosen in order to maximize the ply resonance. Transducers are migrated virtually to each interface between glass and carbon plies in order to overcome the difficulty of wave propagation analysis in such multi-layered system. The wavenumber algorithm demonstrates a better computational performance compared to that of the traditional total focusing method (TFM) in time domain up to 6 times. The glass ply depth and waviness angle can be more accurately presented with relative errors less than 1.5% and 14.8%, respectively. In addition, the resin-rich defect characterization is also achievable with a maximum error of 14.4%. [ABSTRACT FROM AUTHOR]

In this paper, the dynamic and aeroelastic analysis of variable fiber spacing composite (VFSC) laminated plates are carried out. The effects and benefits of changing the fiber distribution pattern on natural frequency and mode shape are explored taking various boundary conditions. Taking cantilever boundary condition flutter characteristics of VFSC plate with different fiber distribution patterns are compared. Further stochasticity of flutter velocity due to randomness in material properties that could arise due to complex manufacturing and fabrication process of VFSC laminates is investigated. The perturbation technique is implemented to perform the stochastic as well as reliability analysis. Various parametric studies are conducted to check the accuracy and efficiency of perturbation technique, by comparing the results with that of Monte Carlo simulation and the first-order reliability method. [ABSTRACT FROM AUTHOR]

In this paper, shielded metal arc welding on the dissimilar joint between 2205 duplex stainless steel and composite bimetallic plates (304 L stainless steel/10CrNi3MoV steel) with a filler metal E2209 was performed. Furthermore, the microstructure, phase, mechanical properties and intergranular corrosion resistance of the joints were investigated and element distributions of the interfaces were characterized. The results show that austenite transformed to ferrite under the influence of welding thermal cycle, and then a large amount of ferrite appeared in heat affected zone (HAZ) of 2205 duplex stainless steel. Coarse bainite grains were formed in HAZ of the 10CrNi3MoV steel near the fusion line with high temperature welding thermal cycle. Fine granular bainite was also generated in HAZ of 10CrNi3MoV steel due to the relatively short exposure time to the active temperature of grain growth. Local peak temperature near the base 10CrNi3MoV steel was still high enough to recrystallize the 10CrNi3MoV steel to form partial-recrystallization HAZ due to phase change. The filler metal was compatible with the three kinds of base materials. The thickness of the elemental diffusion interfaces layers was about 100 µm. The maximum microhardness value was obtained in the HAZ of 2205 duplex stainless steel (287 ± 14 HV), and the minimum one appeared in HAZ of SS304L (213 ± 5 HV). The maximum tensile strength of the welded joint was about 670 ± 6 MPa, and the tensile specimens fractured in ductile at matrix of the composite bimetallic plates. The impact energy of the weld metal and HAZ of the 10CrNi3MoV steel tested at –20 °C were 274 ± 6 J and 308 ± 5 J, respectively. Moreover, the intergranular corrosion resistance of the weldment including 304 L stainless steel, weld metal, HAZs and 2205 duplex stainless steel was in good agreement with the functional design requirements of materials corrosion resistance. [ABSTRACT FROM AUTHOR]

In this paper, a three-dimensional static deformation of arbitrary functionally graded multilayered multiferroic composites plates with weakly and highly conducting imperfect interfaces is derived. The magnetoelectroelastic properties of each layer of the composite plates have been assumed varying throughout the thickness direction. The imperfect interfaces between the layers are assumed to be mechanically compliant, dielectrically and magnetically weakly or highly conducting. In each layer, the state-space approach is firstly applied leading to space variable. Cauchy's problem and adapted Runge-Kutta numerical procedure is used to solve the established state-space equation. The elaborated semi-analytical solution has been propagated throughout the multilayered multiferroic composites plates using the propagator matrix method and accounting the transfers matrices at each imperfect interface. The developed formulas have been programmed and the numerical obtained results have been well compared with available ones. For the computation process, the piezoelectric material BaTi O 3 and piezomagnetic material CoF e 2 O 4 are used. In addition, these numerical tests showed that the proposed solution is in good agreement with the available 3D asymptotic approach, the modified Pagano method, the pseudo-Stroh formalism, the finite elements method and the Peano series solution. Furthermore, the effects of mechanically compliant, dielectrically and magnetically weakly or highly conducting imperfect interface on the static response and the magnetoelectric coupling coefficient of the functionally graded multilayered multiferroic composites plates for various configurations have been also analyzed. It has been carried out that, the bending response and the magnetoelectric coupling coefficient of the multiferroic composites plates remarkably depend on the kind of imperfect interface, the used sequences as well as on the loadings conditions namely mechanical, electric or magnetic, respectively. [ABSTRACT FROM AUTHOR]

In this paper, the non-destructive testing (NDT), structural health monitoring (SHM), and scanning laser Doppler vibrometer (SLDV) techniques were presented to quantify three simulated delaminations inserted at different depths of a unidirectional composite plate. First, the RollerFORM and Omniscan equipment were sufficiently used to identify the delaminations. Second, in conjunction with guided waves, the developed imaging method was successfully used to detect and quantify the interested delaminations. The tuning curves were determined experimentally to define the dominant Lamb wave modes of incident waves. Third, multi-physics three-dimensional finite element simulations of propagating and interacting Lamb waves with delaminations were implemented to extract the wavefield data for wavenumber analysis. The experimental part was conducted to validate the numerical results using SLDV. The effect of the delamination depth on the trapped waves generated over the delamination region was studied numerically and experimentally. The results showed that trapped waves could be affected by the delamination depth. Both numerical and experimental results demonstrated that the near surface delamination has strong trapped waves over the delamination region while the far surface delamination has weak trapped waves. The energy distribution maps of numerical and experimental wavefields data sufficiently quantified the interested delaminations. A good agreement was achieved between the numerical and experimental results. [ABSTRACT FROM AUTHOR]

Stacking sequence design is indispensable to make efficient use of the material properties of laminated composite materials. These laminated composites are usually fabricated from unidirectional plies of given thickness with fiber orientations limited to a small set of angles (e.g., 0°, +45°, –45°, and 90°). This leads to a combinatorial optimisation problem, which is rather complex to solve. In this paper, a new multi-population-based harmony search algorithm with dynamic interaction of populations, hybridised with a customised neighborhood algorithm to solve the layup sequence design problem of laminate composite plate is presented. Numerical experiments have been carried out by first considering the buckling and failure load optimisation of a laminate composite plate and later studies have been carried out using hybrid laminate plates for maximisation of buckling load and fundamental frequency with varied levels of hybridisation and for various plate aspect ratios. Numerical studies carried out in this paper clearly indicate that proposed dynamic hybrid adaptive harmony search algorithm is an effective combinatorial optimisation tool for stacking sequence optimisation of laminate composite structures and the computational performance is found to be superior when compared to other popular implementations of harmony search algorithm. [ABSTRACT FROM PUBLISHER]

In the present paper, vibration behavior of hybrid laminated composite cylindrical shells reinforced with shape memory alloy fibers is investigated. Material properties of shape memory alloy fibers and composites are accurately considered temperature dependent. Thermo-mechanical properties of shape memory alloy fibers with uniform temperature change are calculated using Brinson's one-dimensional constitutive law. Love's first approximation and first-order shear deformation theory of shells with the von K'arm'an type of geometrical non-linearity are used in conjunction with Hamilton's principle for deriving the equations of motion. The generalized differential quadrature method is employed to solve the coupled partial differential equations. The effects of pre-strain, volume fraction, phase transformation, location of shape memory alloy fibers, boundary conditions and temperature on the fundamental frequency of the hybrid laminated composite cylindrical shells are studied. Results indicate that a small amount of shape memory alloy fibers significantly increases the fundamental frequency and vibration control of the hybrid laminated composite reinforced with shape memory alloy hybrid laminated composite cylindrical shells. [ABSTRACT FROM AUTHOR]

The design of the next generation of aeronautical vehicles is driven by the vastly increased cost of fuel and the resultant imperative for greater fuel efficiency. Carbon fiber composites have been used in aeronautical structures to lower weight due to their superior stiffness and strength-to-weight properties. However, carbon composite material behavior under dynamic ballistic impact and blast loading conditions is relatively unknown. For aviation safety consideration, a computational constitutive model has been used to characterize the progressive failure behavior of carbon laminated composite plates subjected to ballistic impact and blast loading conditions. Using a meso-mechanics approach, a laminated composite is represented by a collection of selected numbers of representative unidirectional layers with proper layup configurations. The damage progression in a unidirectional layer is assumed to be governed by the strain-rate-dependent layer progressive failure model using the continuum damage mechanics approach. The composite failure model has been successfully implemented within LS-DYNA® as a user-defined material subroutine. In this paper, the ballistic limit velocity (V50) was first established for a series of laminates by ballistic impact testing. Correlation of the predicted and measured V50 values has been conducted to validate the accuracy of the ballistic modeling approach for the selected carbon composite material. A series of close-in shock hole blast tests on carbon composite panels were then tested and simulated using the LS-DYNA® Arbitrary-Lagrangian-Eulerian (ALE) method integrated with the Army Research Laboratory (ARL) progressive failure composite model. The computational constitutive model has been validated to characterize the progressive failure behavior in carbon laminates subjected to close-in blast loading conditions with reasonable accuracy. The availability of this modeling tool will greatly facilitate the development of carbon composite structures with enhanced ballistic impact and blast survivability. [ABSTRACT FROM AUTHOR]

Mechanical and thermodynamical properties and thus machinability of carbon fibre reinforced polymer composites significantly depend on the fibre orientation relative to the load direction. However, the orientations of the fibre groups in polymer composites reinforced by chopped carbon fibres are stochastic; therefore, the properties and machinability of such composites are challenging to plan, predict and optimise. We developed four different and novel approaches for fibre detection in polymer composites reinforced by chopped carbon fibres: (i) detecting the fibres through naked eye supported manual drawing, (ii) digital image processing of optical images, (iii) machine learning-based fibre detection, and (iv) rectangle fitting on the outputs of the automated processes using the Chaudhuri and Samal method. The applicability of the novel approaches was tested through optically captured images of polymer composites reinforced by chopped carbon fibres. The developed methods are each capable of detecting fibre groups at the top and bottom of the composite plate with certain limitations. The rectangle fitting approaches performed the best from the point of view of correctly identifying of fibre groups, followed by the machine learning-based and the conventional digital image processed, respectively. As a result of this study, the machining process planning and condition monitoring of polymer composites reinforced by chopped carbon fibres is more deeply supported. [ABSTRACT FROM AUTHOR]

This paper gives a method of obtaining the three-dimensional elastic constants of a completely free orthotropic plate from experimental plate vibration data, using an optimized three-mode Rayleigh formulation that incorporates through-the-thickness shear and rotatory inertia. The author believes this is the first reported attempt employing this formulation for obtaining the frequencies of thick plates with the incorporation of these two phenomena. The primary purpose of this paper is to develop the basic theory and method for this class of plates. The author had earlier utilized the classical lamination theory (which does not include these two effects) with both three and six optimized modes. The forward problem of computing plate vibration frequencies from given elastic constants by the Rayleigh method is solved for three thickness ratios (.075, .1, .125) for an isotropic (aluminum) and an orthotropic (graphite/epoxy) material. The inverse method for extracting the elastic constants from experimental vibration data is then applied to two thick plates fabricated from these materials. The results suggest that the proposed method is potentially useful for rapid, inexpensive extraction of in situ elastic constants of composite plates. The major original contribution of this paper is the novel approach for formulating and solving both the forward and inverse problems for thick plates. [ABSTRACT FROM PUBLISHER]

In this paper, the low-energy impact behavior of a fully biobased composite made of bio-sourced polyamide 11 resin reinforced with flax fibers was investigated. Different composite laminates were studied in order to determine the stacking sequence effects on the impact behavior of these composites. Four stacking sequences were manufactured: unidirectional [0°]8, cross-ply [0°/90°]2s, sandwich-like [02°/902°]s and quasi-isotropic [45°/0/−45°/90°]s. A low impact energy of 3.6 J was applied on these laminates by means of a drop weight impact tower. The impact properties of these lay-ups were ascertained by analysing the impact load history, the maximal displacement of the impactor and the absorbed energy. Damage after impact was further assessed by visual inspections, topographic measurements, C-scan and X-ray micro-tomography observations. The results show that impact damage of composite plates is highly influenced by fiber orientation. The impact test data are in good agreement with damage analysis after impact and indicate that stacking plies in the same orientation lead to a larger induced damage, which is responsible for energy dissipation. The quasi-isotropic composite has the smallest induced damage and the highest peak load. Otherwise, the sandwich-like sequence shows the lowest peak load, the highest energy absorption and significant induced damage. Therefore, it is necessary to choose the most suitable lay-up, in terms of impact behavior, for each considered industrial application. [ABSTRACT FROM AUTHOR]

For a long time, a single grid layer, such as isogrid, have been utilized to strengthen a shell or plate or as an independent structural member for various applications. Laminated grid structures consist of several grid layers that can have different in-plane orientations or can be made from different materials. Therefore, using laminated configuration instead of conventional grids yields to an extensive variety of configurations with different coupling effects and cost. In the current paper, to evaluate the appropriateness of laminated isogrids, the vibration and stability behaviors of a conventional isogrid are compared with corresponding laminated isogrid plate. The first-order shear deformation plate theory as well as the Ritz theorem is utilized to achieve the critical buckling loads and free vibration frequencies of the plates. The influence of increasing the number of isogrid plies and changing pattern geometries on mechanical behaviors of the laminated isogrid plate is also investigated. The results imply that utilization of the laminated isogrids remarkably enhances the buckling load and free vibration frequency values of the plates. [ABSTRACT FROM AUTHOR]

A mesh-less method based on the local Petrov–Galerkin approach is developed and numerically implemented for active tuning and three-dimensional (3D) analysis of free vibration response of functionally graded (FG) shape memory alloy (SMA) sandwich composites. The local symmetric weak formulation is derived based on the 3D equilibrium equations of elasticity and the field variables are interpolated using the moving-least squares approach. Two main goals are followed. Firstly, free vibration analysis of a sandwich plate made of a SMA fiber reinforced composite core and two FG face sheets are presented. A parametric study is performed to investigate the influences of design parameters on the fundamental natural frequency (FNF) of composite structure and also maximize that. Secondly, SMA wires are embedded to fiber reinforced (FR) composite structures to enable precisely active control of their dynamic characteristics and change that in a required manner. To increase the controllability level and tune the complex exhibits, functionally graded shape memory alloys are considered which have the advantage of combining the functionalities of the shape memory effect and those of FG structures. This paper uses multi-layer activation patterns and the polynomial graded orientation angle of SMA wire along the structure thickness to furnish the FR composite designer with a powerful free vibration control tool. Finally, two activation techniques of SMA wires, the active property tuning (APT) and the active strain energy tuning (ASET) techniques, are compared. It is concluded from all investigated cases that the obtained FNF of ASET technique is always larger than the APT technique. [ABSTRACT FROM AUTHOR]

In this paper, the static and fatigue behavior of flax fiber-reinforced composites with and without an interleaved natural viscoelastic layer are investigated. Viscoelastic composite plates consist of a soft natural viscoelastic layer which is confined between two identical flax fiber reinforced composites. Different stacking sequences of specimens are tested with uniaxial tensile loading until failure. The mechanical behavior and the acoustic activity of damage sources in various configurations with and without a viscoelastic layer are compared. The analysis of acoustic emission signals and the macroscopic and microscopic observations led to the identification of the main acoustic signatures of different damage modes dominant in each type of composites (with and without a viscoelastic layer). These results allow better identification of the influence of the impact of a viscoelastic layer on the mechanical behavior of different composites. In addition, static and fatigue flexural behavior of unidirectional composites with and without viscoelastic layer are characterized in 3-point bending tests. The effects of viscoelastic layer on the stiffness, hysteresis loops, and loss factor are studied for various numbers of cycles during cyclic fatigue. [ABSTRACT FROM AUTHOR]

This paper investigates the small- and large-amplitude vibrations of thermally postbuckled graphene-reinforced composite (GRC) laminated plates resting on elastic foundations. The piecewise GRC layers are arranged in a functionally graded (FG) pattern along the thickness direction of the plate. The anisotropic and temperature-dependent material properties of the FG-GRC layers are estimated through the extended Halpin–Tsai micromechanical model. Based on the Reddy's higher order shear deformation plate theory and the von Kármán strain–displacement relationships, the motion equations of the plates are derived. The foundation support, the thermal effect, and the initial deflection caused by thermal postbuckling are also included in the derivation. A two-step perturbation approach is applied to determine the thermal postbuckling equilibrium paths as well as the nonlinear vibration solutions for the FG-GRC laminated plates. The numerical illustrations concern small- and large-amplitude vibration characteristics of thermally postbuckled FG-GRC laminated plates under a uniform temperature field. The effects of graphene reinforcement distributions and foundation stiffnesses on the vibration responses of FG-GRC laminated plates are examined in detail. [ABSTRACT FROM AUTHOR]

This paper addresses the effects of different stacking sequences and seawater on the buckling behavior of hybrid composite plates. For the buckling tests, 12-layered hybrid composite plates were produced using different combinations of carbon, E-glass and aramid fibers, with an epoxy resin system as the matrix (Araldite LY1564/Aradur 3486). The hybrid composite plates were designed at the symmetric orientation angles of [(0/90)3]s, [(30/−60)3]s, [(45/−45)3]s and an anti-symmetric orientation angle of [(0/90)3]2. The hybrid composite samples were divided into groups and were subjected to buckling tests after being kept in different settings for varying periods of time (room temperature for 90 days, Black Sea water for 90 days, Mediterranean Sea water for 90 days, Mediterranean Sea water for 150 days). In light of the data obtained from the tests, the buckling behaviors of the layered hybrid composite plates were examined. The highest critical buckling load occurred in the carbon/aramid/glass (CAG) hybrid samples with the stacking sequence of [(0/90)3]s, whereas the lowest critical buckling load occurred in the carbon/aramid/glass (CAG45) hybrid samples with the stacking sequence of [(45/−45)3]s. It was observed that the critical buckling loads of the samples immersed in seawater decreased when compared to the critical buckling loads of the samples kept at room temperature. It was also found that the critical buckling loads of the hybrid samples immersed in the Mediterranean Sea water, which has high salinity, were lower than the critical buckling loads of the hybrid samples immersed in the Black Sea water, which has lower salinity. [ABSTRACT FROM AUTHOR]

This study presents a novel approach for optimizing the critical buckling load of the stiffened piezolaminated composite plates using a self-adaptive special relativity search (SASRS) algorithm. The fiber orientations in the layers are considered as design variables. The stability equations are first derived based on the classical laminated plate theory (CLPT) with von Karman nonlinearity. The optimization problem is implemented in MATLAB. The optimization results are obtained to indicate the effecs of various boundary conditions, applied voltages, grid shapes, angles of diagonal ribs, and plate aspect ratios on the optimal design. Numerical investigations are carried out for 10-ply symmetrical stiffened piezolaminated plates. The robustness and efficiency of the proposed SASRS algorithm in maximizing the critical buckling load of the stiffened piezolaminated plates are demonstrated by comparing the optimized results from the standard special relativity search (SRS) algorithm. It is found that the proposed optimization method has better performance than the SRS algorithm. [ABSTRACT FROM AUTHOR]

This study examines how structural discontinuities created during production affect glass fiber-reinforced composite plates. Due to geometrical constraints, the composite microstructure's discontinuities can be categorized as inter-ply and intra-ply. Material testing was conducted at the coupon level as an initial step to ascertain material characteristics. Two full-scale models of intra-ply composite samples were manufactured by employing layers of glass fiber-reinforced prepregs. Discontinuities were generated in the samples using a computer numeric control cutter and then manually applied. The discontinuities' impact on the composite laminate's mechanical properties was assessed through full-scale pieces using three-point bending quasi-static tests. Servo-hydraulic actuators were used to conduct tests on the items. The experimental test results were compared with CAE analysis predictions by evaluating sectional fiber volume fraction. The characteristics of local discontinuities were analyzed using a microscope to enhance the findings of the CAE model. This comprehensive approach offers insights into the intricate connection between internal structural inconsistencies and the mechanical properties of continuous glass fiber-reinforced materials. It supports optimizing composite manufacturing processes and improves composite parts' structural reliability. Dislocation areas were found to result in the formation of resin-rich zones in this investigation. The exothermic curing process in the component's zones results in elevated temperatures, leading to a color change in the resin from clear to yellow. The yellow areas are easily recognizable and show decreased mechanical durability. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the flutter characteristics of nanocomposite cantilever trapezoidal plates with non-uniform thickness enriched with either carbon nanotubes (CNTs), graphene nanoplatelets (GNPs), or graphene oxide powders (GOPs) which are distributed functionally graded (FG) in the axial direction. It is assumed that the thickness of the plate and the volume fraction of the nanofillers vary in one direction from the wider clamped edge of the plate to the outer narrower free one. The modeling of the plate is done using the first-order shear deformation theory (FSDT) and the aerodynamic pressure generated by the aerodynamic pressure is modeled using the linear approximation of the piston theory. The material properties of the plate are calculated using the mixing rule (ROM) and the Halpin–Tsai model. The governing equations and boundary conditions at the clamped and free edges of the plate are derived via Hamilton's principle. An approximate solution is applied using the differential quadrature method (DQM) to calculate the natural frequencies and the damping ratios of the plate. Numerical examples show that it is possible to find an optimal thickness variation profile that provides the greatest aeroelastic stability. It is concluded that by considering the same value for the mass fractions of the nanofillers, the highest aeroelastic stability can be attained by utilizing the GNPs as the reinforcers. It is found that to attain further improvement in aeroelastic stability, most nanofillers should be distributed near the clamped edge and away from the outer free edge. [ABSTRACT FROM AUTHOR]

The significance of bi-axial testing is increasing with the use of composites in more complex applications and the advent of new manufacturing techniques (Ash and Welsh. Collection of Technical Papers - AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2004, vol. 2, pp.1402–1412). Existing failure theories have not been proven to be accurate for predicting failure for laminated composites and very limited test data are available for woven composites (Ash and Welsh. Collection of Technical Papers – AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 2004, vol 2, pp.1402–1412). It is believed that the fabrication process used to make composite bi-axial specimens induces initial damage into the specimen (Smits. Exp Anal Nano Eng Mater Struct 2007; 35: 933–934). Two different methods were developed to reduce the amount of damage induced into a bi-axial tests specimen. In addition, the effect of stress concentration due to a center hole added to a composite bi-axial specimen is studied. [ABSTRACT FROM AUTHOR]

A study is carried out on free vibration characteristics of a composite laminated plate under non-uniform gradient temperature distribution along the thickness (NGTDT). The NGTDT will cause different thermal stress and deformation compared with no gradient or uniform gradient temperature distribution along the thickness. The governing equation is established considering the influence of NGTDT using the von Karman–type geometric nonlinearity and the first-order shear deformation theory based on Hamilton's principle. The semi-analysis solution is solved by an iteration method, and it is in good agreement with the results of FEM. The solutions show that the NGTDT leads to the critical buckling temperature of the plate that is no longer constant but varies with different NGTDT, that is, the transition point of the resonant frequency decreasing first and then increasing with the temperature is related to the NGTDT. This is very different from the results caused by no gradient or uniform gradient temperature distribution along the thickness. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and numerical investigation on low velocity impact response of S2 glass/epoxy and aramid/epoxy composite plates. Two different impact energy levels, 20 J and 30 J, were considered for impact tests. The commercial software called LS-DYNA was used in order to perform numerical simulations. The experimental and numerical results were found to be in good agreement. [ABSTRACT FROM AUTHOR]

Discontinuities such as cutouts always cause stress concentration in the structure, which increases the local stress. Understanding the effective parameters on stress concentration and proper selection of these parameters enables the designer to achieve a reliable design. In this paper, the optimum values of the effective parameters on stress distribution around the cutout are determined by genetic algorithm. The fitness function for a genetic algorithm is defined by generalization of the analytical solution based on Lekhnitskii method for different cutouts. The finite element method is used to check the validity of the obtained fitness function. Also, the genetic algorithm was able to predict the optimal value of each effective parameter on stress distribution while keeping constant the values of the other parameters. The results showed that material properties, geometry of cutout and angle load have much effect on stress concentration. [ABSTRACT FROM AUTHOR]

This paper presents a study aimed at evaluating how viscoelastic materials embedded in composite plates affect structural damping during the flight of a civil aircraft. The vibro-acoustic responses of composite fuselage structures realized with embedded viscoelastic damping treatments have been experimentally characterized at different temperature conditions. The real influence of viscoelastic materials on composite structures has been investigated, focusing the investigations on aspects still unknown, related mostly to temperature effects. In order to simulate the temperature level of commercial transport aircraft in cruise flight conditions, tests were performed using a climatic room where temperature and humidity were controlled. Vibrational tests were performed on two composite fuselage skin coupons: one treated with embedded viscoelastic damping treatments and the other one untreated. The tests were performed at temperatures of -35∘C for the untreated composite fuselage structure, and 15∘C,-20∘C,-25∘C and -35∘C for the treated composite fuselage structure. The damping values were carried out by the impulse response decay method and the loss factor was obtained as an average of many repeated acquisitions. In order to maximize the damping effect, the best temperature interval for the treated composite fuselage skin coupon was evaluated, and the behavior for both composite fuselage structures (treated and untreated) was characterized. Thanks to the high number of tests, a statistical analysis was performed in order to validate the approach used. [ABSTRACT FROM AUTHOR]

A first-order shear deformation plate theory model of laminated composite plates subjected to a combined electromagnetic and thermal field is developed. The coupled equations of motion are based on the electromagnetic equations (Faraday, Ampere, Ohm, and Lorentz equations) and thermal equations which are involved in constitutive equations. In order to determine the implications of a number of geometrical and physical features of the model, one special case free vibration of a composite plate immersed in a transversal magnetic field is investigated. Special coupling characteristics between the magnetic, elastic and thermal fields are described in this paper. In addition, the free vibration responses of finite composite rectangular plates immersed in a transversal magnetic field are investigated. The vibration response characteristics of a composite plate are exploited in connection with the magnetic field intensity, thermal load, and electric conductivity of fibrous composite materials. Some pertinent conclusions, which highlight the various effects induced by the electromagnetic-thermo-elastic couplings, are outlined. [ABSTRACT FROM AUTHOR]

This paper presents a wave-based, analytical method for the computation of power transfer coefficients (PTC) to evaluate vibratory power transmitted through a set of angled structural joints that connects an arbitrary number of composite plates. Each joint is only used to hold two adjacent plates together. The elastic wave motions and dispersion properties of the plate are calculated by considering shear deformation, rotary inertia, and material anisotropy. The joint is modeled with stiffness and damping in both translational and rotational directions, and the joint parameters are allowed to differ from one joint to another. The equilibrium conditions at the joint set are derived to solve for the complex amplitude of waves propagating away from it. From the PTCs computed for a particular angle of wave incidence at the junction, the diffuse-field PTCs are calculated using weighted integral of the incidence angle. A comparison with published numerical results for simpler configurations has been performed in order to validate some key aspects of the present analytical formulation. Several numerical examples of two coupled composite sandwich panels are considered to compute PTCs, through which it is clearly demonstrated that the joint compliance and damping as well as the transverse shear deformation and rotary inertia of composite sandwich panels influence the vibratory power transmission through coupled composite plates. [ABSTRACT FROM PUBLISHER]

A mesoscopic, time-dependent finite element model for the simulation of dynamic fracture in laminated composite plates is presented. The computational model allows for the simulation of mesh-objective multiple matrix cracking and delamination in laminated composite plates. The analyses are performed with an emphasis on the quantification of the effect of the loading rate on interacting damage mechanisms, i.e. matrix cracking and delamination. In particular, rate effects on damage initiation, propagation, and interaction between matrix cracking and delamination under low and high velocity impact are studied. Moreover, the paper addresses computational issues related to time continuity in stress/strain and velocity fields, during dynamic simulation, at the time of incorporation of new degrees of freedom in a mesh-objective crack modeling approach. Illustrative numerical examples are presented to show the performance of the model. The model is validated with a fast crack growth simulation in a unidirectional laminate. An impact test on a cross-ply laminated plate is performed in order to study the rate effects on structural response and damage mechanics. [ABSTRACT FROM AUTHOR]

This paper deals with the study of the parametric instability characteristics of delaminated composite plates subjected to periodic in-plane load. A first order shear deformation theory based on finite element method is developed for studying the instability region of mid-plane delaminated composite plate. A detailed parametric investigation is carried out to study the influence of the delamination area, number of layers, degree of orthotropy, aspect ratio and static in-plane load on the dynamic stability characteristics of delaminated cross-ply plates. The results of vibration and buckling of delaminated composite plates are compared with previous numerical studies in the literature and the authors’ experimental investigations. The boundaries of instability regions are obtained by using Bolotin’s method and are represented in the non-dimensional load amplitude-excitation frequency plane. It is observed that the natural frequencies and the critical buckling load of the plates decrease with an increase in delamination size. The increase in delamination size also causes dynamic instability regions to be shifted to lower excitation frequencies. [ABSTRACT FROM PUBLISHER]

The use of micromechanical models to study composite material's behavior leads to save time and cost. In this paper, bridging micromechanical models have been used in order to observe the behavior of unidirectional laminate composite under fatigue loading. In order to study the fatigue behavior, stiffness degradation has been studied as well as the strength degradation and a driftnet model has been proposed for each of them. The strength degradation has only been studied for the unidirectional fiber, while the stiffness degradation has been studied for the fibers with different fiber angle. The results are compared with macro-mechanical models and other methods in literature. [ABSTRACT FROM AUTHOR]

This paper reports on the fatigue behaviour of surface–cracked glass/polyester composite plates. The machined cracks have various aspect ratios (a/c) and depth ratios (a/t). The propagation behaviour of surface cracks and delamination are investigated under constant-amplitude (R = 0) loading. The stress intensity factor, KI, is obtained using Newman–Raju and Paris and Sih equations, while Kdel is determined using equations given by Suo and Hutchinson and Bao et al. The results were plotted as curves of the typical relationship between the crack growth rate (dc/dN) and the stress intensity factor range (ΔKI) and the delamination propagation rate (db/dN) and the delamination stress intensity factor range (ΔKdel). Material constants A and n were obtained according to the Paris–Erdoğan equation. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and numerical study to understand ballistic behavior of plain-weave hybrid and non-hybrid composites. The effect of hybridization on ballistic limit (V50) was investigated. The hybrid S2 glass-IM7 graphite fibers/toughened SC-79 resin, non-hybrid S2 glass-fiber/toughened SC-79 resin, and non-hybrid IM7 graphite fibers/toughened SC-79 resin composites plates were impacted at various velocities. The three-dimensional dynamic nonlinear finite element code, LS-DYNA, modified with a proposed user-defined nonlinear-orthotropic damage model, was adopted to simulate the experimental results. The combined results obtained from experiments and finite element simulations were then used for determining V50 for each lay-up configuration. Good agreement between experimental and FE results was found from the comparison of dynamic strain and damage patterns. The hybridization found to be very effective on ballistic limit velocities of woven composites. [ABSTRACT FROM PUBLISHER]

Thermal buckling analysis of symmetric and antisymmetric laminated composite plates with clamped and simply supported edges, and containing a hole is presented in this paper. The first-order shear deformation theory in conjunction with the variational energy method is employed in mathematical formulation. The eight-node Lagrangian finite element technique is used to find thermal buckling temperatures of isotropic, glass-epoxy and boron-epoxy laminates. The effects of hole size, angle of ply orientation, lay-up sequences, and boundary conditions on thermal buckling temperatures are investigated. The result is shown in graphical forms for various boundary conditions. [ABSTRACT FROM AUTHOR]

In this study, thermal buckling behaviors of the composite square plates consisting of antisymmetric four laminates with angle crack are examined. Finite element method is used for the solution. First critical buckling loads of an orthotropic plate without crack subjected to unidirectional compression are found. Constraint conditions have been taken two edge clamped and the other edges are free. The thickness of plate is 2 mm (each layer has 0.5 mm thickness). Thermal buckling behaviors of this plate are examined and critical temperatures are determined. Values have been given in the graphs and discussions are presented in the conclusion. [ABSTRACT FROM AUTHOR]

The optimal fundamental frequency of the variable stiffness laminated composite (VSCL) plate are predicted using an improved chaos game optimization technique (ICGO). In this analysis, the design parameters related to the fibre orientations within the layers are considered the discrete integer, i.e. the values vary between − 90 o and 90 o . The fibre orientations are changed linearly concerning the longitudinal geometry coordinate in each ply. The numerical solutions are computed by adopting a four-noded isoparametric element (five degrees of freedom per node). The proposed optimization algorithm's effectiveness, reliability and accuracy have been verified by comparing its optimum results with those of other algorithms in the literature. Also, the effect of the different relevant structural parameters, i.e. the aspect ratios, the edge conditions and the number of layers, on the optimal design, are reported in detail. [ABSTRACT FROM AUTHOR]

The effectiveness of variable fiber spacing composite (VFSC) laminates subjected to thermal loading is compared with uniformly distributed fiber composite (UDFC) laminates. The higher-order shear deformation theory (HSDT) is adopted to develop a FE model for estimating critical thermal buckling load. Three types of fiber distribution patterns are considered to study the effect of the non-uniform spacing distribution of fiber on thermal buckling, and the results are compared with UDFC. Further, a surrogate model based on the radial basis function network (RBFN) is developed to examine the impact of composite properties uncertainty on the critical buckling response of UDFC and VFSC laminates under thermal loading. The RBFN model is found to be highly efficient and possesses a close match with Monte Carlo simulation (MCS). Though the VFSC laminates possess a large deviation (standard deviation) in the buckling temperature, the stochastic effect (standard deviation/mean) shows relatively minimal variation in VFSC and UDFC laminates. The effect of each composite property is investigated for different lamination sequences and boundary conditions. From the sensitivity analysis, the thermal expansion coefficient of matrix (α m) is found to be the most sensitive property for all the investigated cases. Lastly, the RBFN model is utilized to quantify reliability parameters for multiple stochasticity levels. [ABSTRACT FROM AUTHOR]

We propose an asymptotic framework that may be used as a platform to model general thin microstructural plates, and our initiative is twofold. First, it provides an explanation to why so many tailored plate theories have been introduced for modelling plates bearing microstructures. In hypotheses-based plate theories, the microstructural details within each ply are usually smeared out. But it is shown that with such in-ply details properly taken into account, one manages to address, even only with leading-order terms, several key issues, such as transverse shear strain effects, shear locking, etc., whose rationalisation is believed to necessitate higher-order terms. To a certain degree, the proposed formulation can be used as a target for tailoring kinematic shape functions in both Reissner-Mindlin types of plate theories and zig-zag theories. Second, being slender in nature, a microstructural plate should accommodate a stress state that is close to the state of plane stress. This agrees with our findings that the (leading-order) mechanical units of a microstructural plate should be two-dimensional slices parameterised with the thickness coordinate, distinguishing the proposed framework from other plate theories based on asymptotic analysis. To demonstrate what the present framework can predict beyond existing theories, the effects on the behaviour of fibrous laminates due to manufacturing uncertainties are investigated. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to evaluate the effects of certain processing parameters on the mechanical performance of carbon/epoxy towpreg wound composite structures. For this purpose, composite sample productions and their evaluations were conducted in two steps. In the first step, dry winding of carbon/epoxy towpregs was used to produce flat composite plates. Their evaluation was performed by rheological analysis, interlaminar shear tests, and unidirectional tensile tests. In the second step, towpreg dry winding was used to produce composite pressure vessel samples. Their performance was evaluated by observing the effects of various winding process parameters on the safety of the vessels via hydrostatic burst pressure tests. Compared to the traditional wet filament winding, the main difficulty observed was maintaining the "straight towpreg path" necessary for efficient winding operations. This problem was prevented by applying higher tension forces during dry winding. Evaluation of the hydrostatic burst tests in terms of burst pressure, hoop strain and safe failure mode revealed that the optimum pressure vessel performance could be obtained in the vessel samples with "helical-hoop-helical winding layer sequence." On the other hand, use of "complex helical pattern" resulted in no advantages at all, due to basically higher number of undulation zones acting as stress concentration zones. [ABSTRACT FROM AUTHOR]

The implementation of deterministic design approaches in the presence of uncertainty is an adequate design task. Probabilistic methods are then used in structural design procedures, offering structural safety predictions. In this study, reliability-based analysis of a piezoelectric laminated composite plate subjected to the mechanical loads was investigated, accounting for the epistemic source of uncertainty. Material properties of the plate were considered temperature-dependent. The sophisticated mesh-free finite volume approach was employed to actively control the vibration of the temperature-dependent piezoelectric laminated composite plate through the first-order shear deformation principles. The induced vibration was treated as a non-stationary random process, and the generalized failure index was estimated using the first-passage probability concept by adopting the novel asymptotic sampling technique. The veracity of the suggested model was corroborated by alternate approaches in the literature, comprising the finite element approach. Furthermore, the temperature-dependent piezoelectric laminated composite plate with different ply orientations was considered to assess the safety index variation against changes in the ambient temperature and the laminate stacking orientation. The obtained results revealed that with increasing temperature, the reliability of the composite plate reduced. It was also realized that the reliability index is directly correlated with the piezoelectric voltage. [ABSTRACT FROM AUTHOR]

In this study, the failure behavior of laminated composite plates subjected to anticlastic bending is investigated. Anticlastic bending is a special case of bi-axial out-of-plane loading that produces predominantly twisting moment. A test fixture is designed to actualize anticlastic loading condition. Carbon-fiber-reinforced epoxy composite is selected as the material of the specimens. Totally nine different layup configurations are chosen and at least four specimens are tested for each configuration. Acoustic emission monitoring (AEM) is utilized to detect the first-ply-failure load and the accumulation of damage in the laminates. In this method, elastic waves resulting from initiation and progression of damage are detected, and then AE signals are processed to identify the failure modes and determine the first-ply-failure load. A finite element model is developed to simulate the anticlastic bending test. A code is developed using ANSYS parametric design language to predict the first-ply-failure loads using various failure criteria like Tsai-Wu, Hashin, and Puck. The experimental and numerical results are then compared. Relative strengths and weaknesses of the failure criteria in estimating failure of laminated composite plates under anticlastic bending are discussed. [ABSTRACT FROM AUTHOR]

Natural Bouligand structure is a special class of hierarchical architectures, which have proven to be effective in enhancing its mechanical properties. In this work, we demonstrate that the thermal buckling capacity of Carbon Fibre Reinforced Plastics can also be improved by mimicking bio-inspired Bouligand architectures. A finite element approach using commercial software ABAQUS is developed to predict the critical buckling temperature of the Bouligand inspired laminated plates under thermal loading. Numerical predictions show a good agreement with analytical results obtained from the literature. The effectiveness of Bouligand-type composite laminates in enhancing thermal buckling behavior is first confirmed by comparing with unidirectional, cross-ply and quasi-isotropic laminates. We then present the effects of pitch angle and ply thickness on the thermal buckling temperature of bio-inspired Bouligand-type laminates. Finally, we conclude that the improved mechanical and thermal properties can be simultaneously achieved by the Bouligand structure of laminates as the pitch angle is increased. The present study highlights the high thermal buckling behavior of biomimetic Bouligand structure, offering a possibility in developing biomimetic composites with good trade-off between mechanical properties and thermal performance. [ABSTRACT FROM AUTHOR]

A Levi-type analytical solution procedure is developed to characterize static and dynamic deformation response of smart laminated simply-supported composite rectangular plates induced by inclined piezoelectric actuators under (1) constant electrical voltage and (2) time-dependent electrical voltage with excitation frequency. The key to development of this analytical solution is to employ higher order finite integral transform and discretized higher order partial differential unit step function equations. Unlike earlier studies, this research aims to investigate the effect of inclination angle of piezoelectric actuators on static and dynamic deformation response of laminated composite plates under both static and dynamic conditions. The developed analytical solution procedure is implemented computationally through Matlab-based computer code. Its accuracy is initially investigated through convergence study and results comparison with the published literature for a particular case when inclination angle is θ = 0°, which is only limited to bending deformation response. Since there is no published benchmark data for twisting deformation response analysis caused by inclination angle of piezoelectric actuators (θ ≠ 0°), a set of robust and realistic numerical analysis using Abaqus finite element analysis (FEA) is conducted. Good agreement between the analytical and numerical results is observed. Unlike applied electrical voltage, inclination angle of a piezoelectric actuator does not have a significant impact on twisting deformation response during static mode; whereas, both the excitation frequency and inclination angle can significantly influence maximum amplitude of vibration. [ABSTRACT FROM AUTHOR]