@phdthesis{AbuBakar,
  author    = {Abu Bakar, Ilyani Akmar},
  title     = {Computational Analysis of Woven Fabric Composites: Single- and Multi-Objective Optimizations and Sensitivity Analysis in Meso-scale Structures},
  issn      = {1610-7381},
  doi       = {10.25643/bauhaus-universitaet.4176},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20200605-41762},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {151},
  abstract  = {This study permits a reliability analysis to solve the mechanical behaviour issues existing in the current structural design of fabric structures. Purely predictive material models are highly desirable to facilitate an optimized design scheme and to significantly reduce time and cost at the design stage, such as experimental characterization. The present study examined the role of three major tasks; a) single-objective optimization, b) sensitivity analyses and c) multi-objective optimization on proposed weave structures for woven fabric composites. For single-objective optimization task, the first goal is to optimize the elastic properties of proposed complex weave structure under unit cells basis based on periodic boundary conditions. We predict the geometric characteristics towards skewness of woven fabric composites via Evolutionary Algorithm (EA) and a parametric study. We also demonstrate the effect of complex weave structures on the fray tendency in woven fabric composites via tightness evaluation. We utilize a procedure which does not require a numerical averaging process for evaluating the elastic properties of woven fabric composites. The fray tendency and skewness of woven fabrics depends upon the behaviour of the floats which is related to the factor of weave. Results of this study may suggest a broader view for further research into the effects of complex weave structures or may provide an alternative to the fray and skewness problems of current weave structure in woven fabric composites. A comprehensive study is developed on the complex weave structure model which adopts the dry woven fabric of the most potential pattern in singleobjective optimization incorporating the uncertainties parameters of woven fabric composites. The comprehensive study covers the regression-based and variance-based sensitivity analyses. The second task goal is to introduce the fabric uncertainties parameters and elaborate how they can be incorporated into finite element models on macroscopic material parameters such as elastic modulus and shear modulus of dry woven fabric subjected to uni-axial and biaxial deformations. Significant correlations in the study, would indicate the need for a thorough investigation of woven fabric composites under uncertainties parameters. The study describes here could serve as an alternative to identify effective material properties without prolonged time consumption and expensive experimental tests. The last part focuses on a hierarchical stochastic multi-scale optimization approach (fine-scale and coarse-scale optimizations) under geometrical uncertainties parameters for hybrid composites considering complex weave structure. The fine-scale optimization is to determine the best lamina pattern that maximizes its macroscopic elastic properties, conducted by EA under the following uncertain mesoscopic parameters: yarn spacing, yarn height, yarn width and misalignment of yarn angle. The coarse-scale optimization has been carried out to optimize the stacking sequences of symmetric hybrid laminated composite plate with uncertain mesoscopic parameters by employing the Ant Colony Algorithm (ACO). The objective functions of the coarse-scale optimization are to minimize the cost (C) and weight (W) of the hybrid laminated composite plate considering the fundamental frequency and the buckling load factor as the design constraints. Based on the uncertainty criteria of the design parameters, the appropriate variation required for the structural design standards can be evaluated using the reliability tool, and then an optimized design decision in consideration of cost can be subsequently determined.},
  subject      = {Verbundwerkstoff},
  language  = {en}
}
@misc{Ansari,
  type      = {Master Thesis},
  author    = {Ansari, Meisam},
  title     = {Simulation methods for functional and microstructured composite materials},
  doi       = {10.25643/bauhaus-universitaet.4278},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20201103-42783},
  school      = {Bauhaus-Universit{\"a}t Weimar},
  pages     = {110},
  abstract  = {In this thesis, a generic model for the post-failure behavior of concrete in tension is proposed. A mesoscale model of concrete representing the heterogeneous nature of concrete is formulated. The mesoscale model is composed of three phases: aggregate, mortar matrix, and the Interfacial Transition Zone between them. Both local and non-local formulations of the damage are implemented and the results are compared. Three homogenization schemes from the literature are employed to obtain the homogenized constitutive relationship for the macroscale model. Three groups of numerical examples are provided.},
  subject      = {Simulation},
  language  = {en}
}
@article{WangArash,
  author    = {Wang, Quan and Arash, Behrouz},
  title     = {Announcement of a virtual special issue on computational carbon nanoscience},
  series = {Carbon},
  journal   = {Carbon},
  doi       = {10.1016/j.carbon.2015.05.082},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20170428-31695},
  pages     = {370 -- 372},
  abstract  = {The Carbon journal is pleased to introduce a themed collection of recent articles in the area of computational carbon nanoscience. This virtual special issue was assembled from previously published Carbon articles by Guest Editors Quan Wang and Behrouz Arash, and can be accessed as a set in the special issue section of the journal website homepage: www.journals.elsevier.com/carbon. The article below by our guest editors serves as an introduction to this virtual special issue, and also a commentary on the growing role of computation as a tool to understand the synthesis and properties of carbon nanoforms and their behavior in composite materials.},
  subject      = {Kohlenstoff},
  language  = {en}
}
@inproceedings{PopovaDatchevaIankov2003,
  author    = {Popova, E. D. and Datcheva, Maria and Iankov, Roumen},
  title     = {Mechanical Models with Interval Parameters},
  doi       = {10.25643/bauhaus-universitaet.348},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20111215-3482},
  year      = {2003},
  abstract  = {In this paper we consider modelling of composite material with inclusions where the elastic material properties of both matrix and inclusions are uncertain and vary within prescribed bounds. Such mechanical systems, involving interval uncertainties and modelled by finite element method, can be described by parameter dependent systems of linear interval equations and process variables depending on the system solution. A newly developed hybrid interval approach for solving parametric interval linear systems is applied to the considered model and the results are compared to other interval methods. The hybrid approach provides very sharp bounds for the process variables - element strains and stresses. The sources for overestimation when dealing with interval computations are demonstrated. Based on the element strains and stresses, we introduce a definition for the values of nodal strains and stresses by using a set-theoretic approach.},
  subject      = {Verbundwerkstoff},
  language  = {en}
}