Showing papers in "Composite Structures in 1994"

TL;DR: In this paper, the effect of void content on the static strength and fatigue life of composite laminates under flexural loading was investigated. And the authors proposed a fracture criterion correlating the ultrasonic attenuation to the strength of composite laminate and showed that voids have a strong detrimental effect on the fatigue life.

TL;DR: In this paper, the concept of heterogeneous porous media is also extended to the molecular level by considering the flow problem in a reinforcement sized with grafted macromolecules, and it is shown that the heterogeneous reinforcement structure may also contribute to the differences observed in measurements of the radial flow and the one-dimensional flow methods.

TL;DR: In this article, the modeling and computer simulation techniques of liquid composite molding processes, i.e., resin transfer molding (RTM) and structural reaction injection molding, are discussed.

TL;DR: In this article, exact solutions for temperature distribution and thermal stresses in simply supported rectangular orthotropic laminate subjected to prescribed boundary conditions under combined thermal and mechanical loading, are presented which will be used to check the accuracy of more generalized numerical tools.

TL;DR: In this article, the optimum design of laminated plates and shells subjected to constraints on strength, stiffness, buckling loads, and fundamental natural frequencies is examined, and a careful selection of lay-up is required to make the best use of the capabilities of the material.

TL;DR: In this paper, a geometrically and physically nonlinear finite element approach is presented for the analysis of mode-I and mixed-mode free edge delamination in composite laminates which properly accounts for the effects of initial thermal and hygroscopic stresses.

TL;DR: In this paper, a low velocity, instrumented impact tests were carried out on sandwich panels made of glass fiber reinforced plastic facings and polyvinylchloride foam core and three different core densities and three core thicknesses were examined.

TL;DR: In this paper, an upper limit of the transverse shear modulus across the corrugations is calculated assuming rigid facings, and the reduction of the effective shearing modulus due to deformations of the facings is quantified.

TL;DR: In this paper, a higher-order shear deformation theory and the conventional first-order theory are used to develop a finite element method to analyse accurately the bending and free vibration behavior of laminated composite beams, using nine-noded isoparametric elements.

TL;DR: In this article, the performance of the bonded repairs of a plate containing an inclined central through-crack under a biaxial loading was studied, and the problem of how to optimize the patch fibre orientation with single- or double-sided patching was discussed.

TL;DR: Crack growth and residual strength tests have been conducted on both Glare 3 and Glare 4 material as discussed by the authors, showing improvements in fatigue life of up to 100 times and improvements in residual strength of 40% compared with those for 2024-T3 monolithic aluminium alloy.

TL;DR: Based on generalized laminate plate theory, the formulation of a one-dimensional beam finite element with layer-wise constant shear (BLCS) is presented in this paper, which is equivalent to a first-order shear deformation beam theory (Timoshenko beam theory) on each layer.

TL;DR: In this article, the authors present the chronological development of a carbon fiber reinforced polymeric material technology to be used in primary structures of commercial aircraft, and the benefits in integrating the development of the material process, structural design and manufacturing evaluations are demonstrated.

TL;DR: In this paper, a simple substructuring technique for formulating these special elements is described, which accounts for the microstructure within a single element within a textile composites, where the microstructural scale of a material is of the same order of magnitude as the structural scale of the component.

TL;DR: In this paper, the buckling behavior of some composite stiffened panel structures subjected to in-plane compression and shear load combinations is analyzed using the finite strip method, a computer aided engineering analysis procedure.

TL;DR: In this article, an incremental linear elastic constitutive equation was used to calculate the residual stresses generated in polymer systems, with emphasis on thermosetting systems which are curing under dimensionally constrained conditions.

TL;DR: In this paper, the elastic buckling modes of pultruded I-beams subjected to various loading conditions are studied and the coupling of lateral and distortional buckling, very likely to appear in thinwalled cross-sections, is investigated.

TL;DR: In this article, an unusual behavior has been found for the form of the exotherm during the isothermal curing of liquid crystalline epoxy resins, which is correlated with the reduction of the extent of liquid crystal character with temperature.

TL;DR: In this paper, the authors investigated the thermal buckling of symmetric and non-symmetric cross-ply composite laminated beams based on first-order shear deformation theory.

TL;DR: In this paper, a successive approximation method was proposed and applied in connection with static and dynamic analyses of homogeneous isotropic, orthotropic and cross-ply laminated hollow cylinders and cylindrical panels.

TL;DR: In this article, an experimental program has been carried out to characterize the tensile behavior of pultruded composite I-shape structural members using coupon specimens of different widths cut from different locations.

TL;DR: In this article, a numerical model for the nonlinear analysis of thick laminates is presented using a multiplicative decomposition of the displacement vector in shell space, the 3D problem is reduced to a 2D problem and several linear and nonlinear examples are presented to illustrate the performance of the developed numerical model.

TL;DR: In this article, an experimental study on the development of a two-dimensional stamping method for the processing of unidirectional fiber reinforced composites with thermoplastic matrices, in which an angle mold and a mechanical press are used.

TL;DR: In this paper, a fracture mechanics based analysis has been used to predict the tensile delamination load of tapered laminated plates and a design is presented for a complex tapered plate with a view to maximising the onset of delamination.

TL;DR: In this article, a simple mathematical model for the sorption process is proposed, which seems to cover satisfactorily the experimental data, based on the idea that besides the diffusion, fast and slow changes in the properties of material are taking place due to the interaction between the epoxy and the fluid.

TL;DR: In this article, an experimental and analytical study was carried out to investigate the buckling and failure characteristics of stiffened compression-loaded panels with holes, and to assess the validity of analytical models used for the design of such panels.

TL;DR: In this article, the IM6 carbon fibers have been surface treated in steps to 20, 200 and 600% as well as the nominal 100% surface treatment, and the results showed that the composite shear and transverse flexural strengths were significantly increased after only the 20%surface treatment level, with further increases in the surface treatment level having only minor effect.

TL;DR: This paper examines the general topic of finite element analysis of composite structures and highlights areas of difficulty where further research and development is necessary.

TL;DR: In this paper, the boundary-value problems of static response under transverse load and free vibration of a general cross-ply doubly curved panel of rectangular planform are presented, where four classical shallow shell theories are used in the formulation, which generates a system of one fourth-order and two second-order partial differential equations with constant coefficients.

TL;DR: In this paper, the authors present a design methodology and associated data base for the damage-tolerant design of adhesively bonded repairs, illustrated by repairs to an edge-cracked panel and to multi-site damage in a fuselage lap joint.