Topology Optimization for Cellular Material Design

2014 ◽  
Vol 1662 ◽  
Author(s):  
Reza Lotfi ◽  
Seunghyun Ha ◽  
Josephine V. Carstensen ◽  
James K. Guest

ABSTRACTTopology optimization is a systematic, computational approach to the design of structure, defined as the layout of materials (and pores) across a domain. Typically employed at the component-level scale, topology optimization is increasingly being used to design the architecture of high performance materials. The resulting design problem is posed as an optimization problem with governing unit cell and upscaling mechanics embedded in the formulation, and solved with formal mathematical programming. This paper will describe recent advances in topology optimization, including incorporation of manufacturing processes and objectives governed by nonlinear mechanics and multiple physics, and demonstrate their application to the design of cellular materials. Optimized material architectures are shown to (computationally) approach theoretical bounds when available, and can be used to generate estimations of bounds when such bounds are unknown.

Author(s):  
Josephine V. Carstensen ◽  
Reza Lotfi ◽  
James K. Guest ◽  
Wen Chen ◽  
Jan Schroers

While topology optimization is typically employed for design at the component-level scale, it is increasingly being used to design the topology of high performance cellular materials. The design problem is posed as an optimization problem with governing unit cell and upscaling mechanics embedded in the formulation, and solved with formal mathematical programming. While design for linear elastic properties is generally well-established, this paper will discuss including nonlinear mechanics in the topology optimization formulation, also in the domain of cellular materials. In particular, the problem of maximizing total energy absorption of a cellular Bulk Metallic Glass material is considered and numerical and experimental analyses of the new design show that it has enhanced performance compared to conventional cellular topologies.


2021 ◽  
Author(s):  
Sina Rastegarzadeh ◽  
Jun Wang ◽  
Jida Huang

Abstract Advances in additive manufacturing enable the fabrication of complex structures with intricate geometric details. It also escalates the potential for high-resolution structure design. However, the increasingly finer design brings computational challenges for structural optimization approaches such as topology optimization (TO) since the number of variables to optimize increases with the resolutions. To address this issue, two-scale TO paves an avenue for high-resolution structural design. The design domain is first discretized to a coarse scale, and the material property distribution is optimized, then using micro-structures to fill each property field. In this paper, instead of finding optimal properties of two scales separately, we reformulate the two-scale TO problem and optimize the design variables concurrently in both scales. By introducing parameterized periodic cellular structures, the minimal surface level-parameter is defined as the material design parameter and is implemented directly in the optimization problem. A numerical homogenization method is employed to calculate the elasticity tensor of the cellular materials. The stiffness matrices of the cellular structures derived as a function of the level parameters, using the homogenization results. An additional constraint on the level parameter is introduced in the structural optimization framework to enhance adjacent cellulars interfaces’ compatibility. Based on the parameterized micro-structure, the optimization problem is solved concurrently with an iterative solver. The reliability of the proposed approach has been validated with different engineering design cases. Numerical results show a noticeable increase in structure stiffness using the level parameter directly in the optimization problem than the state-of-art mapping technique.


2017 ◽  
Vol 868 ◽  
pp. 291-296
Author(s):  
He Ting Qiao ◽  
Shi Jie Wang ◽  
Xiao Ren Lv

In this paper, a two-stage optimization algorithm is proposed to simultaneously achieve the optimum structure and microstructure of lightweight cellular materials. Microstructure is assumed being uniform in macro-scale to meet manufacturing requirements. Furthermore, to reduce the computation cost, the design process is divided into two stages, which are concurrent design and material design. In the first stage, macro density and modulus matrix of cellular material are used both as design variables. Then, the optimum topology of macro-structure and modulus matrix of cellular materials will be obtained under this configuration. In the second stage, topology optimization technology is used to achieve a micro-structure of cellular material which is corresponded with the optimum modulus matrix in the earlier concurrent design stage. Moreover, the effectiveness of the present design methodology and optimization scheme is then demonstrated through numerical example.


Solar Energy ◽  
2019 ◽  
Vol 182 ◽  
pp. 237-244 ◽  
Author(s):  
Ahmed-Ali Kanoun ◽  
Mohammed Benali Kanoun ◽  
Abdelkrim E. Merad ◽  
Souraya Goumri-Said

2021 ◽  
Vol 11 (8) ◽  
pp. 3538
Author(s):  
Mauricio Arredondo-Soto ◽  
Enrique Cuan-Urquizo ◽  
Alfonso Gómez-Espinosa

Cellular Materials and Topology Optimization use a structured distribution of material to achieve specific mechanical properties. The controlled distribution of material often leads to several advantages including the customization of the resulting mechanical properties; this can be achieved following these two approaches. In this work, a review of these two as approaches used with compliance purposes applied at flexure level is presented. The related literature is assessed with the aim of clarifying how they can be used in tailoring stiffness of flexure elements. Basic concepts needed to understand the fundamental process of each approach are presented. Further, tailoring stiffness is described as an evolutionary process used in compliance applications. Additionally, works that used these approaches to tailor stiffness of flexure elements are described and categorized. Finally, concluding remarks and recommendations to further extend the study of these two approaches in tailoring the stiffness of flexure elements are discussed.


Author(s):  
Wenyuan Zhang ◽  
Lang He ◽  
Yuanchao Li ◽  
Dongyan Tang ◽  
Xin Li ◽  
...  

All-air-processed perovskite solar cells (PSCs) have attracted increasing attention due to low cost and simplified manufacturing processes. At present, to fabricate efficient and stable PSCs in the air is expected....


2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Maximilian Schrank ◽  
Jens Brimmers ◽  
Thomas Bergs

Continuous generating gear grinding with vitrified grinding worms is an established process for the hard finishing of gears for high-performance transmissions. Due to the increasing requirements for gears in terms of power density, the required surface roughness is continuously decreasing. In order to meet the required tooth flank roughness, common manufacturing processes are polish grinding with elastic bonded grinding tools and fine grinding with vitrified grinding tools. The process behavior and potential of the different bonds for producing super fine surfaces in generating gear grinding have not been sufficiently scientifically investigated yet. Therefore, the objective of this report is to evaluate these potentials. Part of the investigations are the generating gear grinding process with elastic bonded, as well as vitrified grinding worms with comparable grit sizes. The potential of the different tool specifications is empirically investigated independent of the grain size, focusing on the influence of the bond. One result of the investigations was that the tooth flank roughness could be reduced to nearly the same values with the polish and the fine grinding tool. Furthermore, a dependence of the roughness on the selected grinding parameters could not be determined. However, it was found out that the profile line after polish grinding is significantly dependent on the process strategy used.


Author(s):  
Guang Dong ◽  
Zheng-Dong Ma ◽  
Gregory Hulbert ◽  
Noboru Kikuchi ◽  
Sudhakar Arepally ◽  
...  

Efficient and reliable sensitivity analyses are critical for topology optimization, especially for multibody dynamics systems, because of the large number of design variables and the complexities and expense in solving the state equations. This research addresses a general and efficient sensitivity analysis method for topology optimization with design objectives associated with time dependent dynamics responses of multibody dynamics systems that include nonlinear geometric effects associated with large translational and rotational motions. An iterative sensitivity analysis relation is proposed, based on typical finite difference methods for the differential algebraic equations (DAEs). These iterative equations can be simplified for specific cases to obtain more efficient sensitivity analysis methods. Since finite difference methods are general and widely used, the iterative sensitivity analysis is also applicable to various numerical solution approaches. The proposed sensitivity analysis method is demonstrated using a truss structure topology optimization problem with consideration of the dynamic response including large translational and rotational motions. The topology optimization problem of the general truss structure is formulated using the SIMP (Simply Isotropic Material with Penalization) assumption for the design variables associated with each truss member. It is shown that the proposed iterative steps sensitivity analysis method is both reliable and efficient.


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