Design and optimization of nonuniform cellular structures

2017 ◽  
Vol 232 (7) ◽  
pp. 1280-1293 ◽  
Author(s):  
Xin Jin ◽  
Guo-Xi Li ◽  
Meng Zhang
Keyword(s):  
Topology Optimization ◽  
Cellular Structure ◽  
Mechanical Performance ◽  
Design Method ◽  
Lightweight Design ◽  
Structure Design ◽  
Cellular Structures ◽  
Manufacturing Constraints ◽  
Element Analysis ◽  
Design And Optimization

Topology optimization and cellular structure infilling are two important approaches to achieve a lightweight design while meeting the relevant mechanical property requirements. In this work, we present a density-variable cellular structure design method combined with topology optimization while ensuring the manufacturability. The effective mechanical properties are reported as functions of the relative density to combine cellular structures with the topology optimization model. The manufacturing constraints are analyzed and expressed in topology optimization. In addition, density-variable cellular structures are rapidly modeled by mapping the topology optimization results to the relative densities of cells and via the use of user-defined features. It is shown by means of finite element analysis that the proposed design approach can improve the mechanical performance compared to the uniform cellular structure under the same weight reduction. And the choice of cell size for higher stiffness of the designed structure varies with different values of manufacturing constraints.

scholarly journals Multiscale, thermomechanical topology optimization of self-supporting cellular structures for porous injection molds

2019 ◽  
Vol 25 (9) ◽  
pp. 1482-1492
Author(s):  
Tong Wu ◽  
Andres Tovar
Keyword(s):  
Topology Optimization ◽  
Mechanical Performance ◽  
Mechanical Load ◽  
Design Method ◽  
Three Dimensional ◽  
Optimization Method ◽  
Cellular Structures ◽  
Injection Mold ◽  
Computationally Efficient ◽  
Content Type

Purpose This paper aims to establish a multiscale topology optimization method for the optimal design of non-periodic, self-supporting cellular structures subjected to thermo-mechanical loads. The result is a hierarchically complex design that is thermally efficient, mechanically stable and suitable for additive manufacturing (AM). Design/methodology/approach The proposed method seeks to maximize thermo-mechanical performance at the macroscale in a conceptual design while obtaining maximum shear modulus for each unit cell at the mesoscale. Then, the macroscale performance is re-estimated, and the mesoscale design is updated until the macroscale performance is satisfied. Findings A two-dimensional Messerschmitt Bolkow Bolhm (MBB) beam withstanding thermo-mechanical load is presented to illustrate the proposed design method. Furthermore, the method is implemented to optimize a three-dimensional injection mold, which is successfully prototyped using 420 stainless steel infiltrated with bronze. Originality/value By developing a computationally efficient and manufacturing friendly inverse homogenization approach, the novel multiscale design could generate porous molds which can save up to 30 per cent material compared to their solid counterpart without decreasing thermo-mechanical performance. Practical implications This study is a useful tool for the designer in molding industries to reduce the cost of the injection mold and take full advantage of AM.

Topology Optimization of QY70G Truck Crane Turntable Structure

2014 ◽  
Vol 532 ◽  
pp. 466-469 ◽  
Author(s):  
Ye Fei ◽  
Xing Kun Wang ◽  
Wen Min Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Design Method ◽  
Structure Design ◽  
Structural Topology ◽  
Main Bearing ◽  
Element Analysis ◽  
Finite Element Software ◽  
Before And After

Turntable is the main bearing component of truck crane, its structural-load-carrying capacity influences the operational capability directly. This paper adopts the HyperWorks software to make topology optimization for the turntable structure of QY70G truck crane, and carry out the finite element analysis and comparison for the models before and after optimization, which provides an effective method to improve the turntable structure of truck crane. Turntable is one of the important components of truck crane，it bears hoist boom、lifting、luffing mechanism and bob-weight and so on, it is the transfer center of truck crane when it works, the structure will directly affect the lifting performance of the machine. But, the rotary table structure design is affected by the vehicle shape size and installation and space layout. The traditional design method is based the experience of analogy to check by finite element software, it is difficult to get the design scheme which meets the requirements given above and own better strength and stiffness, it also have the disadvantages of long design cycle and large workload. This article is based on the finite element method and structural topology optimal idea, by means of HyperWorks-OptiStruct, makes finite element analysis for the turntable structure of certain QY70G truck crane, and carries on the structural topology in the condition of setted installation location and space, in order to obtain the ideal design plan.

Efficient design optimization of variable-density cellular structures for additive manufacturing: theory and experimental validation

2017 ◽  
Vol 23 (4) ◽  
pp. 660-677 ◽  
Author(s):  
Lin Cheng ◽  
Pu Zhang ◽  
Emre Biyikli ◽  
Jiaxi Bai ◽  
Joshua Robbins ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Cellular Structure ◽  
Lightweight Design ◽  
Scaling Law ◽  
Variable Density ◽  
Cellular Structures ◽  
Efficient Design ◽  
Content Type

Purpose The purpose of the paper is to propose a homogenization-based topology optimization method to optimize the design of variable-density cellular structure, in order to achieve lightweight design and overcome some of the manufacturability issues in additive manufacturing. Design/methodology/approach First, homogenization is performed to capture the effective mechanical properties of cellular structures through the scaling law as a function their relative density. Second, the scaling law is used directly in the topology optimization algorithm to compute the optimal density distribution for the part being optimized. Third, a new technique is presented to reconstruct the computer-aided design (CAD) model of the optimal variable-density cellular structure. The proposed method is validated by comparing the results obtained through homogenized model, full-scale simulation and experimentally testing the optimized parts after being additive manufactured. Findings The test examples demonstrate that the homogenization-based method is efficient, accurate and is able to produce manufacturable designs. Originality/value The optimized designs in our examples also show significant increase in stiffness and strength when compared to the original designs with identical overall weight.

scholarly journals Preparation and properties of silicone rubber materials with foam/solid alternating multilayered structures

2021 ◽  
Author(s):  
Wenhuan Zhang ◽  
Zhaoping Deng ◽  
Hongwei Yuan ◽  
Shikai Luo ◽  
Huayin Wen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silicone Rubber ◽  
Cellular Structure ◽  
Cellular Structures ◽  
Compressive Property ◽  
Solid Layer ◽  
Multilayered Structures ◽  
Element Analysis ◽  
Morphology And Mechanical Properties

AbstractIn this paper, silicone rubber materials with foam/solid alternating multilayered structures were successfully constructed by combining the two methods of multilayered hot-pressing and supercritical carbon dioxide (SCCO2) foaming. The cellular morphology and mechanical properties of the foam/solid alternating multilayered silicone rubber materials were systematically studied. The results show that the growth of the cell was restrained by the solid layer, resulting in a decrease in the cell size. In addition, the introduction of the solid layer effectively improved the mechanical properties of the microcellular silicone rubber foam. The tensile strength and compressive strength of the foam/solid alternating multilayered silicone rubber materials reached 5.39 and 1.08 MPa, which are 46.1% and 237.5% of the pure silicone rubber foam, respectively. Finite element analysis (FEA) was applied and the results indicate that the strength and proportion of the solid layer played important roles in the tensile strength of the foam/solid alternating multilayered silicone rubber materials. Moreover, the small cellular structures in silicone rubber foam can provided a high supporting counterforce during compression, meaning that the microcellular structure of silicone rubber foam improved the compressive property compared to that for the large cellular structure of silicone rubber foam.

scholarly journals Lattice Structure Design and Optimization With Additive Manufacturing Constraints

2018 ◽  
Vol 15 (4) ◽  
pp. 1546-1562 ◽  
Author(s):  
Yunlong Tang ◽  
Guoying Dong ◽  
Qinxue Zhou ◽  
Yaoyao Fiona Zhao
Keyword(s):  
Additive Manufacturing ◽  
Lattice Structure ◽  
Structure Design ◽  
Manufacturing Constraints ◽  
Design And Optimization

Two-Scale Topology Optimization With Parameterized Cellular Structures

2021 ◽  
Author(s):  
Sina Rastegarzadeh ◽  
Jun Wang ◽  
Jida Huang
Keyword(s):  
Topology Optimization ◽  
High Resolution ◽  
Structural Optimization ◽  
Optimization Problem ◽  
Material Design ◽  
Homogenization Method ◽  
Elasticity Tensor ◽  
Structure Design ◽  
Cellular Structures ◽  
Mapping Technique

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.

scholarly journals Lightweight Design of Front Suspension Upright of Electric Formula Car Based on Topology Optimization Method

2020 ◽  
Vol 11 (1) ◽  
pp. 15 ◽  
Author(s):  
Jixiong Li ◽  
Jianliang Tan ◽  
Jianbin Dong
Keyword(s):  
Topology Optimization ◽  
Optimization Design ◽  
Lightweight Design ◽  
Geometric Model ◽  
Load Condition ◽  
Optimization Method ◽  
Structure Design ◽  
Front Suspension ◽  
Emergency Braking ◽  
Topology Optimization Method

In order to obtain a lightweight front upright of an electric formula car’s suspension, the topology optimization method is used in the front upright structure design. The mathematical model of the lightweight optimization design is constructed, and the geometric model of the initial design of the front upright is subjected to the ultimate load condition. The structural optimization of a front upright resulted in the mass reduction of the upright by 60.43%. The optimized model was simulated and verified regarding the strength, stiffness, and safety factor under three different conditions, namely turning braking, emergency braking, and sharp turning. In the experiment, the uprights were machined and assembled and integrated into the racing suspension. The experimental results showed that the optimized front uprights met the requirements of performance.

Structure Optimization of Ship Unloader for Weight Reduction by FEA

2012 ◽  
Vol 443-444 ◽  
pp. 713-718
Author(s):  
Sui Ran Yu ◽  
Quan Fei Zhang
Keyword(s):  
Design Method ◽  
Work Conditions ◽  
Structure Design ◽  
Element Analysis ◽  
Traditional Structure ◽  
The Finite Element Analysis ◽  
Strength And Stiffness ◽  
Stress And Deformation ◽  
Fea Analysis

This paper introduces a optimize design method of ship unloader. The traditional structure design method is totally by experience and manual calculation, while this method is using the Finite Element Analysis (FEA) method to optimize the structure of ship unloader. Therefore this method may keep the stress and deformation of the structure under permission with less use of materials. First we use the FEA analysis software ANSYS to analyze the static strength and stiffness of grab ship unloader, and get its stress and deformation under different work conditions. Then we evaluate the results and modify the structures to improve the performances of the structure under the complex working conditions. Case study shows this method is effective and efficient in practical use.

Rapid Modeling and Design Optimization of Multi-Topology Lattice Structure Based on Unit-Cell Library

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Yuan Liu ◽  
Shurong Zhuo ◽  
Yining Xiao ◽  
Guolei Zheng ◽  
Guoying Dong ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Lattice Structure ◽  
Structure Design ◽  
Parametric Modeling ◽  
Unit Cell ◽  
Element Analysis ◽  
Structure Generation ◽  
Cell Library ◽  
Unit Cells ◽  
Property Space

Abstract Lightweight lattice structure generation and topology optimization (TO) are common design methodologies. In order to further improve potential structural stiffness of lattice structures, a method combining the multi-topology lattice structure design based on unit-cell library with topology optimization is proposed to optimize the parts. First, a parametric modeling method to rapidly generate a large number of different types of lattice cells is presented. Then, the unit-cell library and its property space are constructed by calculating the effective mechanical properties via a computational homogenization methodology. Third, the template of compromise Decision Support Problem (cDSP) is applied to generate the optimization formulation. The selective filling function of unit cells and geometric parameter computation algorithm are subsequently given to obtain the optimum lightweight lattice structure with uniformly varying densities across the design space. Lastly, for validation purposes, the effectiveness and robustness of the optimized results are analyzed through finite element analysis (FEA) simulation.

scholarly journals Backbone cup – a structure design competition based on topology optimization and 3D printing

2016 ◽  
Vol 7 ◽  
pp. A1 ◽  
Author(s):  
Ji-Hong Zhu ◽  
Kai-Ke Yang ◽  
Wei-Hong Zhang
Keyword(s):  
Topology Optimization ◽  
3D Printing ◽  
Experimental Approach ◽  
Mechanical Performance ◽  
Turnaround Time ◽  
Structure Design ◽  
The Finite Element Method ◽  
New Approach ◽  
Design Competition ◽  
Testing Approach

This paper addresses a structure design competition based on topology optimization and 3D Printing, and proposes an experimental approach to efficiently and quickly measure the mechanical performance of the structures designed using topology optimization. Since the topology optimized structure designs are prone to be geometrically complex, it is extremely inconvenient to fabricate these designs with traditional machining. In this study, we not only fabricated the topology optimized structure designs using one kind of 3D Printing technology known as stereolithography (SLA), but also tested the mechanical performance of the produced prototype parts. The finite element method is used to analyze the structure responses, and the consistent results of the numerical simulations and structure experiments prove the validity of this new structure testing approach. This new approach will not only provide a rapid access to topology optimized structure designs verifying, but also cut the turnaround time of structure design significantly.

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