Large-Scale Three-Dimensional Anisotropic Topology Optimization of Variable-Axial Composite Structures

Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Enpei Zhao ◽  
Wei Zhang ◽  
Kazuhiro Saitou

Abstract Variable-axial fiber-reinforced composites allow for local customization of fiber orientation and thicknesses. Despite their significant potential for performance improvement over the conventional multiaxial composites and metals, they pose challenges in design optimization due to the vastly increased design freedom in material orientations. This paper presents an anisotropic topology optimization (TO) method for designing large-scale, 3D variable-axial composite structures. The computational challenge for large-scale 3D TO with extremely low volume fraction is addressed by a tensor-based representation of 3D orientation that would avoid the 2π periodicity of angular representation such as Eular angles, and an adaptive meshing scheme, which, in conjunction with PDE regularization of the density variables, refines the mesh where structural members appear and coarsens where there is void. The proposed method is applied to designing a heavy-duty drone frame subject to complex multi-loading conditions. Finally, the manufacturability gaps between the optimized design and the fabrication-ready design for Tailored Fiber Placement (TFP) is discussed, which motivates future work toward fully-automated design synthesis.

2021 ◽  
pp. 1-15
Author(s):  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Enpei Zhao ◽  
Kazuhiro Saitou

Abstract Variable-axial fiber-reinforced composites allow for local customization of fiber orientation and thicknesses. Despite their significant potential for performance improvement over the conventional multiaxial composites and metals, they pose challenges in design optimization due to the vastly increased design freedom in material orientations. This paper presents an anisotropic topology optimization method for designing large-scale, 3D variable-axial lightweight composite structures subject to multiple load cases. The computational challenges associated with large-scale 3D anisotropic topology optimization with extremely low volume fraction are addressed by a tensor-based representation of 3D orientation that would avoid the 2π periodicity of angular representations such as Euler angles, and an adaptive meshing scheme, which, in conjunction with PDE regularization of the density variables, refines the mesh where structural members appear and coarsens where there is void. The proposed method is applied to designing a heavy-duty drone frame subject to complex multi-loading conditions. Finally, the manufacturability gaps between the optimized design and the fabrication-ready design for Tailored Fiber Placement (TFP) is discussed, which motivates future work toward a fully-automated design synthesis.


2021 ◽  
Author(s):  
Philipp Hofer ◽  
Erich Wehrle

The design of structures using topology optimization can improve the structural performance and save material, in turn reducing costs. Using a framework of large-scale, three-dimensional topology optimization implemented by the authors in an open-source multiphysical software, we investigate the influence of uncertain loading on the optimized design. Direct differentiation is used to reveal the relationship between displacements and applied force, giving an efficient and effective tool to postprocess optimized topologies. The developed methodology for the assessment of the sensitivity with respect to applied forces is explored using two three-dimensional examples: the classic MBB cantilever and a cableway pylon. The advantages and limitations of this method are discussed.


2021 ◽  
Author(s):  
Kazuhiro Saitou ◽  
Yuqing Zhou ◽  
Tsuyoshi Nomura ◽  
Wei Zhang ◽  
Enpei Zhao

2001 ◽  
Author(s):  
Jay R. Sayre ◽  
Alfred C. Loos

Abstract Vacuum assisted resin transfer molding (VARTM) has shown potential to significantly reduce the manufacturing cost of high-performance aerospace composite structures. In this investigation, high fiber volume fraction, triaxially braided preforms with through-the-thickness stitching were successfully resin infiltrated by the VARTM process. The preforms, resin infiltrated with three different resin systems, produced cured composites that were fully wet-out and void free. A three-dimensional finite element model was used to simulation resin infusion into the preforms. The predicted flow patterns agreed well with the flow pattern observed during the infiltration process. The total infiltration times calculated using the model compared well with the measured times.


2013 ◽  
Vol 19 (6) ◽  
pp. 1678-1687 ◽  
Author(s):  
Jean-Pierre Da Costa ◽  
Stefan Oprean ◽  
Pierre Baylou ◽  
Christian Germain

AbstractThough three-dimensional (3D) imaging gives deep insight into the inner structure of complex materials, the stereological analysis of 2D snapshots of material sections is still necessary for large-scale industrial applications for reasons related to time and cost constraints. In this paper, we propose an original framework to estimate the orientation distribution of generalized cylindrical structures from a single 2D section. Contrary to existing approaches, knowledge of the cylinder cross-section shape is not necessary. The only requirement is to know the area distribution of the cross-sections. The approach relies on minimization of a least squares criterion under linear equality and inequality constraints that can be solved with standard optimization solvers. It is evaluated on synthetic data, including simulated images, and is applied to experimental microscopy images of fibrous composite structures. The results show the relevance and capabilities of the approach though some limitations have been identified regarding sensitivity to deviations from the assumed model.


2013 ◽  
Vol 367 ◽  
pp. 145-150
Author(s):  
Jia Lian Cao ◽  
Jun Yong Li ◽  
Chao Yan Wan

To complete the optimization of large-scale structure such as vehicle body efficiently, a new topology optimization method which combines with sub-structural analysis technology is proposed. With HyperWorks/Optistruct for a platform: first, the finite element model of the light rail vehicle body including sub-structure and non sub-structure is created; second, analyze the most dangerous condition using static reduction method which based on sub-structure technology, output the reduction matrix, generate the sub-structure; and then optimization model is defined including that design variables is the element density, objective function is the minimum volume fraction and constraint is the definition of stress, then enter the reduction matrix, and choose the non sub-structure area for topology optimization; Finally, based on the results, redesign the structure and get the improved one according to the technical requirements and practical experience.


2011 ◽  
Vol 308-310 ◽  
pp. 886-889 ◽  
Author(s):  
Yang Jun Luo ◽  
Xiao Xiang Wu ◽  
Alex Li

For generating a more reasonable initial layout configuration, a three-dimensional topology optimization methodology of the steel-concrete composite structure is presented. Following Solid Isotropic Material with Penalization (SIMP) approach, an artificial material model with penalization for elastic constants is assumed and elemental density variables are used for describing the structural layout. The considered problem is thus formulated as to find the optimal material density distribution that minimizes the material volume under specified displacement constraints. By using the adjoint variable method for the sensitivity analysis, the optimization problem is efficiently solved by the gradient-based optimization algorithm. Numerical result shows that the proposed topology approach presented a novel structural topology of the simply-supported steel-concrete composite beam.


Author(s):  
Amir Hooshmand ◽  
Matthew I. Campbell

AbstractThis paper presents a new technique for shape and topology optimization of fluid channels using generative design synthesis methods. The proposed method uses the generative abilities of graph grammars with simulation and analysis power of conventional computational fluid dynamics methods. The graph grammar interpreter GraphSynth is used to carry out graph transformations, which define different topologies for a given multiple-inlet multiple-outlet problem. After evaluating and optimizing the generated graphs, they are first transformed into meaningful three-dimensional shapes. These solutions are then analyzed by a computational fluid dynamics solver for final evaluation of the possible solutions. The effectiveness of the proposed method is checked by solving a variety of available test problems and comparing them with those found in the literature. Furthermore, by solving very complex large-scale problems, the robustness and effectiveness of the method is tested. To extend the work, future research directions are presented.


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