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ispartof: pages:1-8 ispartof: TexComp 12, 12th International Conference on Textile Composites pages:1-8 ispartof: TexComp-12, International Conference on Textile Composites location:Rayleigh, NC, USA date:26 May - 29 May 2015 status: published

Realistic descriptions of a carbon-epoxy 2/2 twill woven composite are generated by a stochastic multi-scale modelling approach. First, experimental data are collected on the short- and long-range variations in the reinforcement structure. Statistical information of each tow path parameter is computed in terms of mean, standard deviation and correlation information. Next, virtual reinforcements are constructed as a combination of average trends with zero-mean deviations. Depending on the presence of cross-correlation, either the Monte Carlo Markov Chain algorithm or a cross-correlated Series Expansion is applied to generate the random tow path deviations. The stochastic tow path instances are subsequently used to construct virtual composite specimens in the WiseTex format. Each specimen possesses the statistical data of the experimental samples on average. ispartof: pages:4741-4750 ispartof: Proceedings of the International Conference on Uncertainty in Structural Dynamics pages:4741-4750 ispartof: USD location:Leuven date:15 Sep - 17 Sep 2014 status: published

Realistic virtual textile composites are generated of a carbon-epoxy 2/2 twill woven composite. Each specimen, spanning ten by ten unit cells, possesses the short- and long-range variability characterised from experimental samples in prior work. A stochastic multi-scale modelling approach is presented to simulate many random reinforcements as combination of average trends with zero-mean deviations. Depending on the presence of cross-correlation, either the Monte Carlo Markov Chain method or Series Expansion technique is applied to generate the tow path deviations. Virtual specimens are acquired in the WiseTex format that reproduce the statistical information of the experimental samples on average. ispartof: pages:1-8 ispartof: Proceedings of the 16th European Conference on Composite Materials pages:1-8 ispartof: ECCM location:Seville, Spain date:22 Jun - 26 Jun 2014 status: published

ariability in textile composites is substantial. A full characterisation of the internal geometry supports material design and increases the reliability of numerical simulations. An approach is presented and tested to obtain a full statistical description of the internal structure of a carbon-epoxy 2/2 twill woven composite, produced using resin transfer moulding. In a first step experimental data are collected using micro-CT to characterise the short range, i.e. within unit cell dimensions, and optical imaging for the long range, spanning several unit cells. The statistical information of the tow reinforcement is quantified per tow type, warp and weft direction, in terms of standard deviation and correlation length. The largest variation is found for the in-plane tow centroid coordinate with a significantly different behaviour in warp and weft direction. Tow cross-sectional properties such as area and aspect ratio vary within the unit cell size with limited scatter. Cross-correlation between neighbouring tows is only observed for the in-plane position. In a second step the statistical data are the input for a multi-scale modelling strategy to generate virtual specimens with random tow reinforcement. While the mean trends of each tow property are directly taken from the experiments, the deviations are generated by two different geometry generators. The properties without cross-correlation are produced using a Markov Chain algorithm, while the cross-correlated in-plane coordinate is generated using the Karhunen-Loève series expansion. Virtual specimens are obtained which possess the same statistical information as present in the experimental samples. ispartof: pages:219-226 ispartof: Proceedings of the IX International Conference on Structural Dynamics vol:2014-January pages:219-226 ispartof: EURODYN 2014 location:Porto, Portugal date:30 Jun - 2 Jul 2014 status: published

ispartof: Book of Abstracts for 1st International Conference on Mechanics of Composites ispartof: MECHCOMP location:Stony Brook date:8 Jun - 12 Jun 2014 status: published

A stochastic multi-scale modelling approach is discussed using the textile preprocessor software WiseTex. Random unit cell structures are acquired by generating variable tow reinforcement consisting of systematic trends, determined from experimental data, added with stochastic deviations, produced by a recently proposed Markov Chain algorithm. The input statistical information is collected from a prior experimental campaign quantifying the tow path using X-ray micro-computed tomography. The tow information is transformed in the WiseTex format that is compatible with the micromechanical analysis tool TexComp to evaluate the stiffness properties corresponding to each virtual sample. This stochastic model is tested using statistical data of a seven ply polymer textile composite, with each ply consisting of a twill 2/2 woven carbon fabric in an epoxy matrix. © (2012) by the Katholieke Universiteit Leuven Department of Mechanical Engineering All rights reserved. ispartof: pages:5053-5064 ispartof: Proceedings of the International Conference on Uncertainty in Structural Dynamics (USD2012) vol:6 pages:5053-5064 ispartof: International conference on Uncertainty in Structural Dynamics (USD) location:Leuven, Belgium date:17 Sep - 19 Sep 2012 status: published