Variation Analysis of Non-Rigid Assembly Using FEM and Fractals

Author(s):  
Xiaoyun Liao ◽  
G. Gary Wang

Many studies on the assembly of non-rigid parts suggest that the part variation affects the assembly dimensional quality. However, little is known about how the detailed microstructure of part variation influences the assembly dimensional quality. In this paper, a new method based on the finite element method (FEM) and fractal geometry is proposed to explore the influence of the part variation microstructure on the assembly dimensional variation. In the new method, a special fractal function, the Weierstrass-Mandelbrot (W-M) function, is used to extract and represent the characteristics of the part variation microstructure. FEM is applied to analyze the deformation of non-rigid parts by integrating the part variation microstructure. The contribution of the detailed part variation to the final assembly deformation is obtained by the influence coefficients method. The proposed method is implemented by using commercial software tools, ANSYS and Matlab. The proposed method is illustrated through a case study on an assembly of two flat sheet metal parts. This new approach should benefit high precision assemblies.

2006 ◽  
Vol 129 (8) ◽  
pp. 844-851 ◽  
Author(s):  
Jianpeng Yue ◽  
Jaime A. Camelio ◽  
Melida Chin ◽  
Wayne Cai

Dimensional variation in assembled products directly affects product performance. To reduce dimensional variation, it is necessary that an assembly be robust. A robust assembly is less sensitive to input variation from the product and process components, such as incoming parts, subassemblies, fixtures, and welding guns. In order to effectively understand the sensitivity of an assembly to input variation, an appropriate set of metrics must be defined. In this paper, three product-oriented indices, including pattern sensitivity index, component sensitivity index, and station sensitivity index, are defined. These indices can be utilized to measure the variation influence of a pattern, an individual part, and/or component, and components at a particular station to the dimensional quality of a final assembly. Additionally, the relationships among these sensitivity indices are established. Based on these relationships, the ranges of the sensitivity indices are derived. Finally, a case study of a sheet metal assembly is presented and discussed to illustrate the applicability of these metrics.


Author(s):  
YanFeng Xing

Fixture layout can affect deformation and dimensional variation of sheet metal assemblies. Conventionally, the assembly dimensions are simulated with a quantity of finite element (FE) analyses, and fixture layout optimization needs significant user intervention and unaffordable iterations of finite element analyses. This paper therefore proposes a fully automated and efficient method of fixture layout optimization based on the combination of 3dcs simulation (for dimensional analyses) and global optimization algorithms. In this paper, two global algorithms are proposed to optimize fixture locator points, which are social radiation algorithm (SRA) and GAOT, a genetic algorithm (GA) in optimization toolbox in matlab. The flowchart of fixture design includes the following steps: (1) The locating points, the key elements of a fixture layout, are selected from a much smaller candidate pool thanks to our proposed manufacturing constraints based filtering methods and thus the computational efficiency is greatly improved. (2) The two global optimization algorithms are edited to be used to optimize fixture schemes based on matlab. (3) Since matlab macrocommands of 3dcs have been developed to calculate assembly dimensions, the optimization process is fully automated. A case study of inner hood is applied to demonstrate the proposed method. The results show that the GAOT algorithm is more suitable than SRA for generating the optimal fixture layout with excellent efficiency for engineering applications.


Author(s):  
Jianpeng Yue ◽  
Jaime A. Camelio ◽  
Melida Chin

Dimensional variation in assembled products directly affects product performance. To reduce dimensional variation it is necessary that an assembly be robust. A robust assembly is less sensitive to input variation from the product and process components such as incoming parts, subassemblies, fixtures and welding guns. In order to effectively understand the sensitivity of an assembly to input variation, an appropriate set of metrics must be defined. In this paper, three product oriented indices including pattern sensitivity index, component sensitivity index and station sensitivity index are defined. These indices can be utilized to measure the variation influence of a pattern, an individual part and/or component, and components at a particular station to the dimensional quality of a final assembly. Additionally, the relationships among these sensitivity indices are established. Based on these relationships, the ranges of the sensitivity indices are derived. Finally, a case study of a sheet metal assembly is presented and discussed to illustrate the applicability of these metrics.


2007 ◽  
Vol 10-12 ◽  
pp. 12-17 ◽  
Author(s):  
T. He ◽  
L.M. Qiao ◽  
X.F. Xu ◽  
Y.L. Fu

To reduce the complexity and difficulty of costing of quality of manufactures, a new approach about the costing of quality including the method, structure, system and case study based on the business process rule is proposed in the paper. Comparing with the traditional method, the new idea can improve the performance of the costing of quality at the aspect of generalization, customization, evolution and reconfiguration by establish the mapping among the user application, the business rule and the business process.


2019 ◽  
Vol 2 (2) ◽  
pp. 177-187
Author(s):  
Venessa Agusta Gogali ◽  
Fajar Muharam ◽  
Syarif Fitri

Crowdfunding is a new method in fundraising activities based online. Moreover, the level of penetration of social media to the community is increasingly high. This makes social activists and academics realize that it is important to study social media communication strategies in crowdfunding activities. There is encouragement to provide an overview of crowdfunding activities. So the author conducted a research on "Crowdfunding Communication Strategy Through Kolase.com Through Case Study on the #BikinNyata Program Through the Kolase.com Website that successfully achieved the target. Keywords: Strategic of Communication, Crowdfunding, Social Media.


1992 ◽  
Vol 26 (9-11) ◽  
pp. 2345-2348 ◽  
Author(s):  
C. N. Haas

A new method for the quantitative analysis of multiple toxicity data is described and illustrated using a data set on metal exposure to copepods. Positive interactions are observed for Ni-Pb and Pb-Cr, with weak negative interactions observed for Ni-Cr.


2020 ◽  
Vol 10 (4) ◽  
Author(s):  
Mauro Sciarelli ◽  
Silvia Cosimato ◽  
Giovanni Landi

AbstractOver the last decades, Benefit Corporations arouse as a new corporate structure, alternative to traditional ones and pointing to offer a new approach to the management of business and sustainability issues. These companies' activities are statutory aimed at bridging for-profit and no-profit activities; thus, they intentionally and statutory pursue economic purposes together with social and environmental ones, to create a positive impact on economy, society and environment. Even though, Italian and other national laws set some specific disclosure duties for Benefit Corporations, especially in terms of Environmental, Social and Governance (ESG) issues, the literature still calls for further research on the topic. Therefore, this paper is aimed at contributing to bridge this gap, investigating the way Italian Benefit Corporations approach ESG disclosure. To this end, an exploratory analysis has been conducted, implementing a qualitative method, based on a multiple case study strategy. Even though the descriptive nature of the study, the achieved findings pointed out that the Benefit Corporation structure not necessarily implies a better approach to ESG.


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