Isogeometric shape optimization of smoothed petal auxetic structures via computational periodic homogenization
Article dans une revue avec comité de lecture
An important feature that drives the auxetic behaviour of the star-shaped auxetic structures is the hinge-functional connection at the vertex connections. This feature poses a great challenge for manufacturing and may lead to significant stress concentrations. To overcome these problems, we introduced smoothed petal-shaped auxetic structures, where the hinges are replaced by smoothed connections. To accommodate the curved features of the petal-shaped auxetics, a parametrisation modelling scheme using multiple NURBS patches is proposed. Next, an integrated shape design frame work using isogeometric analysis is adopted to improve the structural performance. To ensure a minimum thickness for each member, a geometry sizing constraint is imposed via piece-wise bounding polynomials. This geometry sizing constraint, in the context of isogeometric shape optimization, is particularly interesting due to the non-interpolatory nature of NURBS basis. The effective Poisson ratio is used directly as the objective function, and an adjoint sensitivity analysis is carried out. The optimized designs – smoothed petal auxetic structures – are shown to achieve low negative Poisson’s ratios, while the difficulties of manufacturing the hinges are avoided. For the case with six petals, an in-plane isotropy is achieved.
Showing items related by title, author, creator and subject.
Article dans une revue avec comité de lectureWANG, Zhen-Pei; POH, Leong Hien; ZHU, Yilin; DIRRENBERGER, Justin; FOREST, Samuel (Elsevier, 2019)This paper focuses on a systematic isogeometric design approach for the optimal petal form and size characterization of tetra-petals auxetics, considering both plane stress and plane strain conditions. The underlying ...
Article dans une revue avec comité de lectureDIRRENBERGER, Justin; FOREST, Samuel; JEULIN, Dominique (Elsevier, 2014)The size of representative volume element (RVE) for 3D stochastic fibrous media is investigated. A statistical RVE size determination method is applied to a specific model of random microstructure: Poisson fibers. The ...
Article dans une revue avec comité de lectureVIARD, Antoine-Emmanuel; DIRRENBERGER, Justin; FOREST, Samuel (Elsevier, 2020)Under tension low carbon steel exhibits inhomogeneous plastic deformation. This instability called Piobert-Lüders banding creates fronts of localized strain that propagate in the structure. To date, Lüders banding has been ...
Chapitre d'ouvrage scientifiqueDIRRENBERGER, Justin; FOREST, Samuel; JEULIN, Dominique (Springer New York, 2019)Architectured materials involve geometrically engineered distributions of microstructural phases at a scale comparable to the scale of the component, thus calling for new models in order to determine the effective properties ...
Multiscale modeling of the elasto-plastic behavior of architectured and nanostructured Cu-Nb composite wires and comparison with neutron diffraction experiments Article dans une revue avec comité de lectureGU, T.; MEDY, J. R.; KLOSEK, Vincent; CASTELNAU, Olivier; FOREST, Samuel; HERVÉ-LUANCO, Eveline; LECOUTURIER-DUPOUY, F.; PROUDHON, Henry; RENAULT, Pierre Olivier; THILLY, Ludovic; VILLECHAISE, Patrick (Elsevier, 2019)Nanostructured and architectured copper niobium composite wires are excellent candidates for the generation of intense pulsed magnetic fields ( 100T) as they combine both high strength and high electrical conductivity. ...