In this paper, dynamic stability of a LAMINATED COMPOSITE BEAM subjected to a tip follower force is investigated. Using elementary theory of bending, Euler-Bernoulli BEAM theory and Classical Lamination Theory (CLT), bending moment of LAMINATED COMPOSITE BEAM is calculated with respect to it’s extensional, bending and bending-extensional coupling stiffness matrices, A, B and D, and dynamic stability equation of LAMINATED BEAM is established. Due to similarity between this equation and isotropic stability equation, as an assumption, isotropic BEAM boundary conditions are used for COMPOSITE BEAM. Cantilever- free boundary conditions are used and a closed form solution is established. Flutter instability problems for symmetric and un-symmetric LAMINATED BEAMs are solved by this method and results are compared with finite element results in literatures. Considering the simplicity of the present method, results show good agreement with the finite element method. Finally dynamic stability behavior of laminates with different stacking sequences are investigated by present method and effect of different parameters such as fiber orientation, number of layers, and stacking sequence, on the flutter load and corresponding frequency of symmetric and un -symmetric laminates are investigated.

The structural analysis of an infinite unsymmetric LAMINATED COMPOSITE Timoshenko BEAM over Pasternak viscoelastic foundation under moving load is studied. The BEAM is subjected to a travelling concentrated load. Closed form steady state solutions, based on the first-order shear deformation theory (FSDT) are developed. In this analysis, the effect of bend-twist coupling is also evaluated. Selecting of an appropriate displacement field for deflection of the COMPOSITE BEAM and using the principle of total minimum potential energy, the governing differential equations of motion are obtained and solved using complex infinite Fourier transformation method. The dynamic response of unsymmetric angle-ply LAMINATED BEAM under moving load has been compared with existing results in the literature and a very good agreement is observed. The results for variation of the deflection, bending moment, shear force and bending stress are presented. In addition, the influences of the stiffness, shear layer viscosity of foundation, velocity of the moving load and also different thicknesses of the BEAM on the structural response are studied.

Nowadays, piezoelectric transducers are widely applied because of their capability to convert environmental energies (e. g. mechanical vibrations) into the electrical energy. In an energy harvester structure, not only piezoelectric characteristics but also properties of the non-piezoelectric part of the energy harvesting structure are highly important. Therefore, in the present research, electrical energy generation from forced vibrations of a COMPOSITE BEAM with the piezoelectric layer is considered. For this purpose, firstly, the governing equations of the system are obtained using Euler-Bernoulli BEAM theory. Then, Kantorovich method was used to calculate the output voltage for a COMPOSITE BEAM with the piezoelectric layer. To verify the analytical method, the results were compared to the finite-element modeling results. Furthermore, the effects of fiber orientation angle and layup arrangement in the COMPOSITE BEAM with piezoelectric layer on the amount of harvested energy were investigated. According to the obtained results, by increasing the elastic modulus of the COMPOSITE BEAM and its effect on the damping ratio of the structure, considerably higher energy is harvested. Then, the effects of COMPOSITE BEAM dimensions, the ratio of COMPOSITE BEAM thickness to the piezoelectric layer thickness, the concentrated mass, and the damping ratio on the amount of harvested energy were studied. The results show that using the COMPOSITE materials and by proper design of layup and fiber orientation angle in each layer, it is possible to get different equivalent elastic modulus in the COMPOSITE BEAM, and consequently alter natural frequency of the system and output voltage amplitude of the circuit.

In this paper, a new inverse hyperbolic shear deformation theory is proposed, formulated and validated for a variety of numerical examples of LAMINATED COMPOSITE BEAM for the static responses. The proposed theory based upon shear strain shape function yields nonlinear distribution of transverse shear stresses and also satisfies traction free boundary conditions. Principle of virtual work is employed to develop the governing differential equations. A Levy type closed form solution methodology is also proposed for crossply simply supported BEAMs which limits applicability. However, it provides accurate solution which is free from any numerical /computational error. It is observed that the present theory can be more accurately applied for the modeling of LAMINATED COMPOSITE BEAMs at the same computational cost as that of other shear deformation theories.

This paper investigates the influence of temperature on the active vibration control of LAMINATED COMPOSITE cantilever BEAMs using collocative experimental and simulation techniques. The system identification toolbox of the MATLAB simulation tool is utilized to obtain the transfer function of the plant model. The adequate vibration attenuation of the glass-epoxy cantilever BEAM operating in various thermal environments is achieved using the proportional (P) and proportional-integral-derivative (PID) controllers. The vibration attenuation characteristics of the developed control algorithms are comprehensively investigated for a wide temperature range of –20 °C to 60 °C using PZT-5H patches. Particular emphasis is given to the vibration control of the fundamental natural frequency of the LAMINATED COMPOSITE cantilever BEAM. The obtained results of open and closed-loop models are presented in both time and frequency domains. The results indicate that for all the temperatures considered, the PID controller is found to be more effective in vibration attenuation than the P controller. The vibration attenuation performance of the cantilever BEAM considerably improved at the higher magnitude of temperature values. The natural frequency of the system is reduced continuously with an increase in temperature.

Various industrial sectors require highly specialized and efficient materials for applications in fields such as the military, aeronautics, aerospace, and mechanical and civil engineering. COMPOSITE materials that meet the stringent requirements across these domains have become prominent, often serving as structural components and requiring precise mathematical modeling. Zigzag (ZZ) and Layerwise (LW) theories are commonly used for LAMINATED-BEAM structural analysis. Although the LW theory provides superior accuracy, it suffers from an increase in unknowns as the number of layers grows. Conversely, the ZZ theory is less computationally intensive and less accurate. This study proposes an exponential high-order zigzag function with a unified kinematic formulation to enhance the accuracy of the ZZ theory. The results were compared with those of existing models and demonstrated excellent agreement with the reference solutions, irrespective of the layer count or slenderness index, making it a more efficient choice for LAMINATED-BEAM analysis.

Nowadays, the practical applications of shell elements such as BEAMs having thin-wall cross-sections are increasing greatly in various fields of engineering including aerospace, nuclear, marine, and automotive industries. This is due to their ability to optimally use structural materials and simultaneously reduce the total weight of the structure. Fiber polymer COMPOSITEs also have different conspicuous properties such as high stiffness-to-weight and strength-to-weight ratios, corrosion resistance, and high strength. Therefore, LAMINATED COMPOSITE C-section BEAM elements simultaneously possess both the beneficial features of fiber-reinforced COMPOSITE materials and thin-walled cross-sections at the same time. Motivated by these facts, in this research, the flexural-torsional stability of multi-layer fibrous COMPOSITE tapered BEAM-columns with channel-section subjected to axial and bending loads is investigated. For this purpose, the total potential energy governing the problem is extracted based on Vlasov’s model for small non-uniform torsion along with the classical LAMINATED plate theory. Then, using Ritz’s methodology as an analytical solution technique, the endurable buckling load is calculated. Eventually, the effect of important parameters such as stacking sequences, fiber COMPOSITE materials, boundary conditions, axial load eccentricity, and axial preloading on the linear buckling capacity of double-tapered multi-layer COMPOSITE BEAM-column with channel-section under axial load and end moment is investigated.

This paper presents size dependent stability analysis a cantilever micro LAMINATED BEAM embedded in elastic medium by using the modified coupled stress theory which includes the length scale parameter. The micro BEAM subjected to compressive load is considered as three COMPOSITE laminas and embedded in elastic medium which is modelled in the Winkler foundation model. In the obtaining of the governing equations, the energy principle is used. In the solution of the buckling problem, the energy based Ritz method is implemented with algebraic polynomials. In order to accuracy obtained expressions and used method, a comparative study is performed. Many parametric studies are presented in order to investigate the buckling of LAMINATED micro BEAMs. For this purpose, effects of stacking sequence of laminas, geometric parameters, length scale parameter, fiber orientation angle, the parameter of elastic medium on critical buckling loads of LAMINATED micro BEAMs are investigated.

In this article, the dispersion of propagation waves in an arbitrary direction in LAMINATED COMPOSITE plates is studied in the framework of elasticity. Three-dimensional field equations of elasticity are considered, and the characteristic equation is obtained on employing the continuity of displacements and stresses at the layers' interfaces. Obtained characteristic equation is further simplified by making use of the properties of the block matrices. Some important particular cases such as of free waves on reducing plates to single layer and the surface waves when thickness tends to infinity are also discussed. Numerical results are also obtained and represented graphically.