A Large-scale Topology Optimization Method for Three-dimensional Transient Thermal-fluid Flows

2017 ◽  
Vol 2017.30 (0) ◽  
pp. 312
Author(s):  
Kentaro YAJI ◽  
Masao OGINO ◽  
Cong CHEN ◽  
Kikuo FUJITA
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.


Leonardo ◽  
2016 ◽  
Vol 49 (3) ◽  
pp. 226-231
Author(s):  
Yoon Young Kim ◽  
Jae Chun Ryu ◽  
Eunil Kim ◽  
Hyoungkee Kim ◽  
Byungseong Ahn

The authors propose a variational art algorithm: a virtual system-based optimization algorithm developed for generating images. Observing that the topology optimization method used for multiphysics system design can produce two- or three-dimensional layouts without baselines, the authors propose to expand it beyond engineering applications for generating images. They have devised a virtual physical system—a heat-path system—that “interprets” the optimization-based process of image generation as the simultaneous drawing of multiple strokes in a painting.


2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Chih-Hsing Liu ◽  
Chen-Hua Chiu ◽  
Ta-Lun Chen ◽  
Tzu-Yang Pai ◽  
Mao-Cheng Hsu ◽  
...  

This study presents a topology optimization method to synthesize an innovative compliant finger for grasping objects with size and shape variations. The design domain of the compliant finger is a trapezoidal area with one input and two output ports. The topology optimized finger design is prototyped by three-dimensional (3D) printing using flexible filament, and be used in the developed gripper module, which consists of one actuator and two identical compliant fingers. Both fingers are actuated by one displacement input, and can grip objects through elastic deformation. The gripper module is mounted on an industrial robot to pick and place a variety of objects to demonstrate the effectiveness of the proposed design. The results show that the developed compliant finger can be used to handle vulnerable objects without causing damage to the surface of grasped items. The proposed compliant finger is a monolithic and low-cost design, which can be used to resolve the challenge issue for robotic automation of irregular and vulnerable objects.


Author(s):  
Filippo Cucinotta ◽  
Marcello Raffaele ◽  
Fabio Salmeri

AbstractStochastic lattice structures are very powerful solutions for filling three-dimensional spaces using a generative algorithm. They are suitable for 3D printing and are well appropriate to structural optimization and mass distribution, allowing for high-performance and low-weight structures. The paper shows a method, developed in the Rhino-Grasshopper environment, to distribute lattice structures until a goal is achieved, e.g. the reduction of the weight, the harmonization of the stresses or the limitation of the strain. As case study, a cantilever beam made of Titan alloy, by means of SLS technology has been optimized. The results of the work show the potentiality of the methodology, with a very performing structure and low computational efforts.


Author(s):  
Takayuki Yamada ◽  
Shinji Nishiwaki ◽  
Atsuro Iga ◽  
Kazuhiro Izui ◽  
Masataka Yoshimura

This paper proposes a new level set-based topology optimization method for thermal problems that deal with generic heat transfer boundaries including design-dependent boundary conditions, based on the level set method and the concept of the phase field theory. First, a topology optimization method using a level set model incorporating a fictitious interface energy derived from the concept of the phase field theory is briefly discussed. Next, a generic optimization problem for thermal problems is formulated based on the concept of total potential energy. An optimization algorithm that uses the Finite Element Method when solving the equilibrium equation and updating the level set function is then constructed. Finally, several three-dimensional numerical examples are provided to confirm the utility and validity of the proposed topology optimization method.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6252
Author(s):  
Xiao Shen ◽  
Haitao Han ◽  
Yancheng Li ◽  
Changxiang Yan ◽  
Deqiang Mu

In this paper, to improve the heat dissipation efficiency of a radiator for focal plane assemblies, a topology optimization method is introduced into the design process. For the realization of the optimization, an objective of maximal thermal stiffness concerning the radiator is formulated. The topology optimization is performed under the same mass constraint of 2.05 kg as the initial design. To improve the manufacturability of topology optimization result, an inverse design is conducted to reconstruct a new model. In transient thermal simulation, the average maximal temperature on focal plane assemblies with a reconstructed radiator is 8.626 °C, while the average maximal temperature with the initial design is 9.793 °C. Compared to the initial design, a decrease of 1.167 °C on maximal temperature is achieved. As the heat dissipation efficiency of the proposed radiator design is improved compared to the initial design, it is meaningful in future applications.


Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Haitao Luo ◽  
Rong Chen ◽  
Siwei Guo ◽  
Jia Fu

At present, hard coating structures are widely studied as a new passive damping method. Generally, the hard coating material is completely covered on the surface of the thin-walled structure, but the local coverage cannot only achieve better vibration reduction effect, but also save the material and processing costs. In this paper, a topology optimization method for hard coated composite plates is proposed to maximize the modal loss factors. The finite element dynamic model of hard coating composite plate is established. The topology optimization model is established with the energy ratio of hard coating layer to base layer as the objective function and the amount of damping material as the constraint condition. The sensitivity expression of the objective function to the design variables is derived, and the iteration of the design variables is realized by the Method of Moving Asymptote (MMA). Several numerical examples are provided to demonstrate that this method can obtain the optimal layout of damping materials for hard coating composite plates. The results show that the damping materials are mainly distributed in the area where the stored modal strain energy is large, which is consistent with the traditional design method. Finally, based on the numerical results, the experimental study of local hard coating composites plate is carried out. The results show that the topology optimization method can significantly reduce the frequency response amplitude while reducing the amount of damping materials, which shows the feasibility and effectiveness of the method.


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