Bridging between topology optimization and additive manufacturing via Laplacian smoothing

2021 ◽  
pp. 1-12
Author(s):  
Bruno Barroqueiro ◽  
A. Andrade-Campos ◽  
J. Dias-de-Oliveira ◽  
R.A.F. Valente

Abstract The potential of Additive Layer Manufacturing (ALM) is high, with a whole new set of manufacturable parts with unseen complexity being offered. Moreover, the combination of Topology Optimization (TO) with ALM has brought mutual advantages. However, the transition between TO and ALM is a non-trivial step that requires a robust methodology. Thus, the purpose of this work is to evaluate the capabilities of adopting the commonly used Laplacian smoothing methodology as the bridging tool between TO and ALM. Several algorithms are presented and compared in terms of efficiency and performance. Most importantly, a different concept of Laplacian smoothing is presented as well as a set of metrics to evaluate the performance of the algorithms, with the advantages and disadvantages of each algorithm being discussed. In the end, the proposed mutable diffusion Laplacian algorithm is presented and exhibits less volume shrinkage and shows better preservation of some geometrical features such as thin members and edges. Moreover, a new volume constraint is presented, decreasing the resulting structural changes in the presented geometry and improving the final mesh quality.

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Ercan M. Dede ◽  
Shailesh N. Joshi ◽  
Feng Zhou

Topology optimization of an air-cooled heat sink considering heat conduction plus side-surface convection is presented. The optimization formulation is explained along with multiple design examples. A postprocessing procedure is described to synthesize manifold or “water-tight” solid model computer-aided design (CAD) geometry from three-dimensional (3D) point-cloud data extracted from the optimization result. Using this process, a heat sink is optimized for confined jet impingement air cooling. A prototype structure is fabricated out of AlSi12 using additive layer manufacturing (ALM). The heat transfer and fluid flow performance of the optimized heat sink are experimentally evaluated, and the results are compared with benchmark plate and pin-fin heat sink geometries that are conventionally machined out of aluminum and copper. In two separate test cases, the experimental results indicate that the optimized ALM heat sink design has a higher coefficient of performance (COP) relative to the benchmark heat sink designs.


Author(s):  
Ercan M. Dede ◽  
Shailesh N. Joshi ◽  
Feng Zhou

Topology optimization of an air-cooled heat sink considering heat conduction plus side-surface convection is presented. The optimization formulation is explained along with multiple design examples. A post-processing procedure is described to synthesize water-tight solid model computer-aided design (CAD) geometry from 3-D point-cloud data extracted from the optimization result. Using this process, a heat sink is optimized for confined jet impingement air cooling. A prototype structure is fabricated out of AlSi12 using additive layer manufacturing (ALM). The heat transfer and fluid flow performance of the optimized heat sink is experimentally evaluated, and the results are compared with benchmark plate and pin-fin heat sink geometries that are conventionally machined out of aluminum and copper. In two separate test cases, the experimental results indicate that the optimized ALM heat sink design has a higher coefficient of performance relative to the benchmark heat sink designs.


2019 ◽  
Vol 16 (3) ◽  
pp. 276-289
Author(s):  
N. V. Savenkov ◽  
V. V. Ponyakin ◽  
S. A. Chekulaev ◽  
V. V. Butenko

Introduction. At present, stands with running drums are widely used for various types of tests. Power stands play a special role. Such stands take the mechanical power from the driving wheels of the car. This simulates the process of movement of the vehicle under operating conditions. Such equipment has various designs, principles of operation and performance. It is also used in tests that are different by purpose, development stages and types: research, control, certification, etc. Therefore, it is necessary in order to determine the traction-speed, fuel-efficient and environmental performance characteristics.Materials and methods. The paper provides the overview of the power stands with running drums, which are widespread on the domestic market. The authors carried out the analysis of the main structural solutions: schemes of force transfer between the wheel and the drum; types of loading devices; transmission layout schemes and features of the control and measuring complex. The authors also considered corresponding advantages and disadvantages, recommended spheres of application, demonstrated parameters and characteristics of the units’ workflow, presented components and equipment.Discussion and conclusions. The authors critically evaluate existing models of stands with running drums. Such information is useful for choosing serial models of stands and for developing technical tasks for designing or upgrading the equipment.


Author(s):  
Christine Ipsen ◽  
Marc van Veldhoven ◽  
Kathrin Kirchner ◽  
John Paulin Hansen

The number of people working from home (WFH) increased radically during the coronavirus (COVID-19) pandemic. The purpose of this study was therefore to investigate people’s experiences of WFH during the pandemic and to identify the main factors of advantages and disadvantages of WFH. Data from 29 European countries on the experiences of knowledge workers (N = 5748) WFH during the early stages of lockdown (11 March to 8 May 2020) were collected. A factor analysis showed the overall distribution of people’s experiences and how the advantages and disadvantages of WFH during the early weeks of the pandemic can be grouped into six key factors. The results indicated that most people had a more positive rather than negative experience of WFH during lockdown. Three factors represent the main advantages of WFH: (i) work–life balance, (ii) improved work efficiency and (iii) greater work control. The main disadvantages were (iv) home office constraints, (v) work uncertainties and (vi) inadequate tools. Comparing gender, number of children at home, age and managers versus employees in relation to these factors provided insights into the differential impact of WFH on people’s lives. The factors help organisations understand where action is most needed to safeguard both performance and well-being. As the data were collected amidst the COVID-19 pandemic, we recommend further studies to validate the six factors and investigate their importance for well-being and performance in knowledge work.


Author(s):  
James M. Gibert ◽  
Georges M. Fadel

This paper provides two separate methodologies for implementing the Voronoi Cell Finite Element Method (VCFEM) in topological optimization. Both exploit two characteristics of VCFEM. The first approach utilizes the property that a hole or inclusion can be placed in the element: the design variables for the topology optimization are sizes of the hole. In the second approach, we note that VCFEM may mesh the design domain as n sided polygons. We restrict our attention to hexagonal meshes of the domain while applying Solid Isotropic Material Penalization (SIMP) material model. Researchers have shown that hexagonal meshes are not subject to the checker boarding problem commonly associated with standard linear quad and triangle elements. We present several examples to illustrate the efficacy of the methods in compliance minimization as well as discuss the advantages and disadvantages of each method.


2014 ◽  
Vol 6 ◽  
pp. 734568 ◽  
Author(s):  
Liang Tang ◽  
Jie Wu ◽  
Jinhao Liu ◽  
Cuicui Jiang ◽  
Wen-Bin Shangguan

Control Arm (CA) of a suspension plays an important role in the automotive ride comfort and handling stability. In this paper, the topology optimization model including ball joints and bushing for topology optimization of an aluminium CA is established, where a ball joint is simplified as rigid elements and the elastic properties of a rubber bushing are estimated using Mooney-Rivlin constitutive law. A method for treating with multiple loads in topology optimization of CA is presented. Inertia relief theory is employed in the FEA model of the CA in order to simulate the large displacement motion characteristics of the CA. A CA is designed based on the topology optimization results, and the strength, natural frequency, and rigidity of the optimized CA are calculated. The calculated results show that the performances of the optimized CA with the proposed model meet the predetermined requirements.


2018 ◽  
Vol 25 (6) ◽  
pp. 1059-1073 ◽  
Author(s):  
Weifeng Chen ◽  
Hu Weimin ◽  
Dejiang Li ◽  
Shaona Chen ◽  
Zhongxu Dai

AbstractGraphene (graphene) is a new type of two-dimensional inorganic nanomaterial developed in recent years. It can be used as an ideal inorganic nanofiller for the preparation of polymer nanocomposites because of its high mechanical strength, excellent electrical conductivity and plentiful availability (from graphite). In this review, the preparation methods of graphene/polymer nanocomposites, including solution blending, melt blending and in situ polymerization, are introduced in order to study the relationship between these methods and the final characteristics and properties. Each method has an influence on the final characteristics and properties of the nanocomposites. The advantages and disadvantages of these methods are discussed. In addition, a variety of nanocomposites with different properties, such as mechanical properties, electronic conductivity, thermal conductivity and thermal properties, are summarized comprehensively. The potential applications of these nanocomposites in conductive materials, electromagnetic shielding materials, photocatalytic materials and so on, are briefly presented. This review demonstrates that polymer/graphene nanocomposites exhibit superior comprehensive performance and will be applied in the fields of new materials and novel devices. Future research directions of the nanocomposites are also presented.


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