1,720,965 research outputs found
Analysis of multiple crack initiation and propagation in glass/epoxy woven fabrics under cyclic loadings
No full text
Considerazioni sulla propagazione a fatica di cricche trasversali in laminati compositi: confronto tra cross-ply e DCB
No full textSviluppo e validazione di un modello analitico per la previsione delle proprietà elastiche e delle tensioni locali in compositi tessuti
No full textA multiscale strategy for assessing the micro-scale stress distribution in the matrix of textile composites
No full textIn this work, a multiscale strategy for estimating the local stress fields in the matrix of woven composites is presented. This is a fundamental tool for predicting the static and fatigue bundle crack initiation. The strategy adopts first an analytical model to estimate the average stresses in the bundles at the meso-scale. These are used as an input for 2D Finite Element (FE) analyses on representative volume elements to calculate the local stress fields in the matrix at the micro-scale. In particular, the cumulative distribution function of the local stress components in the matrix are predicted. From that, the average stresses in a control volume of the matrix are obtained, to be used for assessing the crack initiation in off-axis bundles. The entire strategy is validated experimentally, in terms of elastic properties, and numerically, in terms of average bundle stresses and local stress fields obtained through full 3D FE analyses
Sviluppo e validazione di un modello analitico per la stima delle proprietà elastiche di compositi tessuti in presenza di cricche
No full textFatigue damage evolution in woven composites with different architectures
No full textThe influence of the reinforcement architecture on the fatigue behaviour of woven composites is evaluated.
Glass/epoxy laminates with stacking sequence UD-woven-UD were produced with the woven layer at 0/90◦ and
± 45◦. Plain and twill fabrics with the same matrix and fibres were used. The damage evolution was monitored
during tension-tension fatigue tests, leading to a comparison between laminates based on life to crack initiation,
crack growth and crack density evolution. The fatigue behaviour in terms of life to crack initiation was found to
be predicted through local stresses in the matrix of the bundles, calculated using a recent multi-scale model
Influence of the mesostructure on the fatigue behaviour of textile composites
No full textThe aim of the present work is to analyze the influence of the mesostructure on the fatigue behaviour of textile composites. By affecting the stress distribution within a laminate, the mesostructure largely determines the damage evolution under cyclic loadings. In this work, plain woven fabrics with different number of layers were tested under cyclic loadings along the warp and weft directions, monitoring the damage evolution. The differences in meso- and micro-structure, together with the position of the bundle in the laminate, affect the fatigue-induced damage mechanisms. The stress fields obtained from 3D Finite Element analyses shed light onto the influence of the mesostructure on the damage onset. Eventually, a stress-based strategy to predict the life to crack initiation is proposed and validated against experimental data
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