Computational Modeling of Progressive Failure in FRP Composite Laminates Subjected to Static and Impact Transverse loading

In order to arrive at safe and reliable design of composite structures, understanding of the mechanisms and mechanics of damage growth in these materials is of paramount significance. Numerical models, if designed, implemented and used carefully, can be helpful not only to understand the mechanisms and mechanics of damage growth but also to...

Detection of early squats by axle box acceleration

This thesis discusses a new method for detection of short track irregularities, particularly squats, with axle box acceleration (ABA) measurements. A squat is a surface initiated short track defect, associated with high frequency vibrations of the wheel-rail system. High stresses in the contact patch at squats cause accumulation of plastic...

Computational modelling of fibre-reinforced cementitious composites: An analysis of discrete and mesh-independent techniques

Failure patterns and mechanical behaviour of high performance fibre-reinforced cementitious composites depend to a large extent on the distribution of fibres within a specimen. A discrete treatment of fibres enables us to study the influence of various fibre distributions on the mechanical properties of the material. The numerical analysis of...

Multiscale failure modelling of quasi-brittle materials

The conventional multiscale homogenization theory, which has mainly been applied to determine constitutive laws for bulk materials, suffers from two drawbacks when applied to softening materials. Firstly, the coarse scale response is sensitive to the finite element mesh used to discretize the coarse scale domain. Secondly, increasing the size of...

Computational modeling of failure in composite laminates

There is no state of the art computational model that is good enough for predictive simulation of the complete failure process in laminates. Already on the single ply level controversy exists. Much work has been done in recent years in the development of continuum models, but these fail to predict the correct failure mechanism in cases where...

Design strategy structural concrete in 3D focusing on uniform force results and sequential analysis

Introduction (chapter 1) In analysis software models the infrastructural constructions are often reduced to geometrical linear and surface models (plane stress and shell models). The selection of a model much depends on the speed of the analysis process and the total processing time. The increased computer power has boosted the visualisation of...

Computational modelling of rubber-like materials under monotonic and cyclic loading

The simulation of rubber-like material behaviour by means of the finite element method has been described in this study. Proper material models for the numerical description of static hyper-elasticity, the ideal Mullins effect and the Mullins effect with permanent deformation were proposed, respectively. The second focus of this study was the...

Error estimation and adaptive spatial discretisation for quasi-brittle failure

Accuracy of a finite element solution depends greatly on the spatial discretisation of the problem domain. The more refined/enriched discretisation provides better accuracy but also requires more computational cost. For modelling of quasi-brittle failure, the process zone where failure takes place can be very small, thus it is very cost...

Computational modelling of chloride ingress in concrete

Anti-reflective cracking design of (reinforced) asphaltic overlays