COMPOSITEs provide design flexibility because many of them can be moulded into complex shapes. Carbonfibre-reinforced epoxy COMPOSITEs exhibit excellent fatigue tolerance with high specific strength and stiffness. Theseproperties led to their numerous advanced applications ranging from military and civil aircraft STRUCTURES to consumerproducts. The modelling of beams undergoing arbitrarily large displacements and rotations, but small strains, is acommon problem in the application of these engineering COMPOSITE systems. This paper presents a nonlinear finiteelement model able to estimate the deformations of the fibre-reinforced epoxy COMPOSITE beam. The governingequations are based on Euler-Bernoulli Beam Theory (EBBT) with a von Ká rmá n type of kinematic nonlinearity. Anisotropic elasticity is employed for the material model of the COMPOSITE material. Characterization of themechanical properties of the COMPOSITE material is achieved through tensile test while simple laboratory experimentis used to validate the model. Results reveal that COMPOSITE fibre orientation; the type of applied load and boundarycondition affect the deformation characteristics of COMPOSITE STRUCTURES. Nonlinear consideration is important in theanalysis of fibre-reinforced epoxy COMPOSITEs.

The present work is a parametric study of the free vibrational characteristics of laminated square and rectangular plates. To validate the analysis, extensive comparisons with results present in the literature have been made. Some experimental investigations have also been carried out. The effects of material orthotropy, lamination sequence, orientation of fibres in angle ply laminates, boundary conditions, and simplifications arising from neglect of bending stretching coupling [Bij] and reduced bending stiffness matrix [D*] on the modal characteristics are presented. To provide some ideas for standardization of the discretization procedure, studies on the convergence of free vibration with a number of elements have been undertaken initially. Using the finite element solutions, some design curves have been generated to illustrate their use in the quick estimates of natural frequencies in the case of geometrically similar STRUCTURES of varying dimensions.      

This paper presents a novel formulation and numerical solutions for adhesively bonded COMPOSITE joints with non-linear (softening) adhesive behaviour. The presented approach has the capability of choosing arbitrary loadings and boundary conditions. In this model adherends are orthotropic laminates that obey classical lamination theory. The stacking sequences can be either symmetric or asymmetric. Adhesive layer (s) is (are) homogenous and isotropic material. They are modeled as continuously distributed nonlinear (softening) tension/compression and shear springs. In this method by employing constitutive, kinematics and equilibrium equations, sets of differential equations for each inside and outside of overlap zones are derived. In the inside of overlap zone, the set of differential equations is non-linear, that is solved numerically. By solving these equations, shear and peel stresses in adhesive layer (s) as well as deflections, stress resultants and moment resultants in the adherends are determined. Most of adhesives have non-linear behavior, therefore unlike previous methods, in which the adhesive layers are modeled as linear materials, in the presented approach the non-linear behavior is assumed for the adhesive layer and can be used to analyze the most of adhesive joints. The numerical results reveal that in the inside of overlap zone, magnitudes of shear forces are considerably large due to high rate of variation in the bending moments. The developed results are successfully compared with those obtained by finite element analysis using ANSYS. The comparisons demonstrate the accuracy and effectiveness of the aforementioned methods.

Steel-concrete COMPOSITE construction has gained wide acceptance world wide as an alternative to pure steel and pure concrete construction. However, this system is a relatively new concept for the construction industry in Bangladesh. Reinforced concrete members are used in the framing system for most of the buildings since this is the most convenient & economic system for low-rise buildings. However, for medium to high-rise buildings this type of structure is no longer economic because of increased dead load, less stiffness, span restriction and hazardous formwork. Steel-concrete COMPOSITE frame system can provide an effective and economic solution to most of these problems in medium to high-rise buildings. An attempt has been made in this study to explore the cost effectiveness of COMPOSITE construction for medium to high-rise buildings in Bangladesh. A cost versus number of story curve shows that for low-rise buildings RCC frame system is cheaper than COMPOSITE system. However, for buildings with number of stories greater than 15, COMPOSITE construction becomes economic than RCC construction.

Buckling strength of COMPOSITE latticed cylindrical shells is one of the important parameters for studying the failure of these STRUCTURES. In this paper, new governing differential equations are derived for latticed cylindrical shells and their critical buckling axial loads. The nested structure under compressive axial buckling load was analyzed. Finite Element Method (FEM) was applied to model the structure in order to verify the analytical results. The obtained results were validated based upon the results of previous case studies in literature. For the squared type of lattice COMPOSITE shells, a new formula for the buckling load was developed and its value was compared to the critical load, using FEM with 3D beam elements. The processes were carried out for three different materials of Carbon/Epoxy, Kevlar/Epoxy and EGlass/Epoxy.