Monte-Carlo simulation of the durability of glass fibre reinforced composite under environmental stress corrosion

The lifetime distribution of glass fibre subject to permanent environmental stress corrosion is very important for assessing the durability and damage tolerance of composites using glass reinforcement. A mechanical model based on the statistics of flaw spectra during stress corrosion and 3D shear lag model is presented. The proposed approach shows that it is possible to identify the influence of stress corrosion properties on the long term durability of glass fibre reinforced composites (GFRP)

Performance design of reinforced concrete slabs using commercial finite element software

[Abstract]: A fundamental task in the design of reinforced concrete structures is to search for minimum cost through the variation and placement of the quantities of the relatively expensive steel reinforcement without jeopardising the safety of the structure. The use of nonlinear finite element can assist greatly in achieving an economical and safe design. However, commercially available finite element softwares are not designed for this task as most of them have been developed to be used as verification rather than design tools. 'Home-written' software can be designed to achieve this task, however it may suffer from serious drawbacks such as bugs, lack of user friendliness, lack of generality, and unproven reliability. This present study shows that if a given software comes with a scripting interface, it can be easily transformed from a verification tool to a performance design tool. This is illustrated with the use of ABAQUS [1], but it can be adapted to any other software with a scripting interface

Meso-scale finite element investigation into the short and long term strengths of glass fibre reinforced composites

A finite element model is proposed for simulating the short and long term strength of Glass Fibre Reinforced Plastics. The essence of the model is a division of the composite system into a binary system comprising 'fibre elements' to represent the fibres, and 'effective medium' elements to represent the matrix material, which account for other mechanical properties such as shear and transverse stiffness and Poisson's effect. Such a representation stems from the fact that the performance of a composite material is intrinsically controlled by the microstructure of the component materials. Besides, it has the advantage of the power and versatility of the finite element technique. Typical results for short and long term strengths are compared to similar predictions obtained from shear lag theory. Good agreement is obtained for a variety of finite element discretisations

Design and analysis of a composite beam for infrastructure applications - Part II: preliminary investigation in shear and torsion

Bending behaviour was dealt with in the preceding prequel, its associated failure modes identified, and a simplified theoretical approach was proposed for design purposes. However, this approach would not be complete without a simplified method for estimating the shear resistance of the beam and its torsional response

Computation of laminated composite plates using integrated radial basis function networks

This paper reports a meshless method, which is based on radial-basis-function networks (RBFNs), for the static analysis of moderately-thick laminated composite plates using the first-order shear deformation theory. Integrated RBFNs are employed to represent the field variables, and the governing equations are discretized by means of point collocation. The use of integration rather than conventional differentiation to construct the RBF approximations significantly stabilizes the solution and enhances the quality of approximation. The proposed method is verified through the solution of rectangular and non-rectangular composite plates. Numerical results obtained show that the method achieves a very high degree of accuracy and a fast convergence rate

Design and analysis of a composite beam for infrastructure applications - Part I: preliminary investigation in bending

The objective of this study is to contribute to the development of a composite beam for use in civil engineering systems. Based on the limitations in existing concepts, a new beam design is proposed and its behaviour studied. Using the classical beam theory, the Timoshenko beam theory, the Timoshenko plate theory, as well as the transformed section approach, borrowed from reinforced concrete, a simplified analytical approach, which could be used in design, is developed to conduct first and second order analysis of the proposed beam in order to achieve a rational sizing of its section before a rigorous testing regime is carried out. Finally, to validate the analytical model and gain confidence in the design, the analytical and experimental results are compared to a rigorous non linear finite element solution. It was found that the analytical model agreed relatively well with the experiments and the FE analyses, giving confidence in the validity of the underlying assumptions

Design and analysis of a composite beam for infrastructure applications - Part III: experimental results and nonlinear FE analysis

Using the analytical approaches developed, the cross section of the new fibre composite beam described in the prequels to this paper is designed in order to avert secondary failure modes. A series of specimens have been built and put through a thorough testing regime to establish the performance of the beam. To gain confidence in the analytical models and achieve further understanding of the beam behaviour, a rigorous nonlinear finite element analysis is also presented. It was found that the analytical model agreed relatively well with the experiment and the FE analysis, thus validating the underlying assumptions

Plasticity models for the biaxial behaviour of concrete at elevated temperatures, Part II: Implementation and simulation tests

The thermo-mechanical behaviour of concrete at elevated temperatures under multiaxial stress is extremely nonlinear. In Part I we developed a general analytical failure criterion based on the available biaxial test data. Here, the loading surfaces are used to derive the elastic-plastic incremental stress-strain relationships for a plasticity approach, and the model is used to predict experimental strain measurements under biaxial stress. Agreement is shown to be very good. The predictions are also used to suggest possible variations in material parameters such as Poisson's ratio, for which scant data exist