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1

Using metamodeling and fluid-structure interaction analysis in multi-objective optimization of a butterfly valve

Pałys Laura, Mrzygłód Mirosław W.

Computer Assisted Methods in Engineering and Science

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2021

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Vol. 28, no. 1

17--38

EN

Along with the increase in computing power, new possibilities for the use of parametriccoupled analysis of fluid flow machines and metamodeling for many branches of industryand medicine have appeared. In this paper, the use of a new methodology for multi-objective optimization of a butterfly valve with the application of the fluid-structure interaction metamodel is presented. The optimization objective functions were to increasethe value of the KV valve’s flow coefficient while reducing the disk mass. Moreover, theequivalent von Mises stress was accepted as an additional constraint. The centred composite designs were used to plan the measuring point. Full second-order polynomials, non-parametric regression, Kriging metamodeling techniques were implemented. The optimization process was carried out using the multi-objectives genetic algorithm. For eachmetamodel, one of the optimization candidates was selected to verify its results. The besteffect was obtained using the Kriging method. Optimization allowed to improve the KVvalue by 37.6%. The metamodeling process allows for the coupled analysis of the fluidflow machines in a shorter time, although its main application is geometry optimization.

2

Prediction of the optimum tensile – shear strength through the experimental results of similar and dissimilar spot welding joints

Mahmood Najmuldeen Yousif

Archive of Mechanical Engineering

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2020

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LXVII, nr 2

197--210

EN

Resistance spot welding is the most significant joining technique utilized in various industries, like automotive, boilers, vessels, etc., that are commonly subjected to variable tensile-shear forces due to the unsuitable use of the input spot welding variables, which mainly cause the welded joints failure during the service life of the welded assembly. So, in order to avoid such failures, the welding quality of some materials like aluminum must be improved taking into consideration the performance and weight saving of the welded structure. Thus, the need for optimizing the used welding parameters becomes essential for predicting a good welded joint. Accordingly, this study aims at investigating the influence of the spot welding variables, including the squeeze time, welding time, and current on the tensile-shear force of the similar and dissimilar lap joints for aluminum and steel sheets. It was concluded that the use of Taguchi design can improve the welded joints strength through designing the experiments according to the used levels of the input parameters in order to obtain their optimal values that give the optimum tensile-shear force as the response. As a consequence of the present work, the optimal spot welding parameters were successfully obtained.

3

Approximating curve by a single segment of B-Spline or Bézier curve directly in CAD environment

Sobolak Mariusz, Połowniak Piotr, Marciniec Adam, Jagiełowicz Patrycja Ewa

Advances in Manufacturing Science and Technology

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2020

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Vol. 44, nr 3

84--92

EN

The paper presents the method of approximating curves with a single segment of the B-Spline and Bézier curves. The method for determining a single curve segment using the optimization methods in the CATIA environment is shown. The algorithms of simulated annealing and design of experiment are used for optimization. For the same purpose, a new original procedure for determining the distance between the given curves using explicit parameters in the CATIA environment was also used. This approximation of the cyclic curves results in the curve oscillation as shown in the examples. The results show that the approximation method with Bézier curve using control points as “free” points can be applied to obtain the best results of approximation.

4

A statistical approach to simulate instances of archeological findings fragments

Renno Fabrizio, Lanzotti Antonio, Papa Stefano

Journal of Automation Mobile Robotics and Intelligent Systems

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2019

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Vol. 13, No. 1

46--64

EN

First aim of this paper is to describe a methodology developed to create virtual fragments of archeological archetypes in CAD (Computer Aided Design) environment. A simple Reverse Engineering (RE) technique was adopted to reconstruct the shape of vases allowing the archeologists, and so the CAD inexpert personnel, to use it. Moreover, another relevant aspect is the definition of a procedure to simulate shape errors on the virtual prototypes to make more realistic the results. The characteristics of the fragments to be reproduced were selected by means of Design of Experiment (DOE) techniques. So, an algorithm was implemented to simulate the shape error, related to the working operations, that represents the typical noise for the feature recognition of archeological findings. Furthermore, this algorithm can make more complex the hypotheses related to the Gaussian model of simulation of the error and can adapt the value of the shape error (i.e. increasing it) according to the data gathered in archaeological excavation. The case study was based on the definition of a catalogue of archetypes of the black Campanian vases studied and classified by the archeologist J.P. Morel. The procedure conceived was applied to five (among one hundred) vases of the virtual catalogue obtaining forty instances of fragments affected by errors and so creating virtual mock-ups of typical pieces which may be found in the archeological site considered for the case study.

5

Identifying Optimal Friction Stir Welding Process Parameters for 2024 Al Alloy Butt Joints

Kluz Rafał, Bucior Magdalena, Kubit Andrzej

Advances in Science and Technology. Research Journal

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2019

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Vol. 13, no 4

48--53

EN

Friction stir welding (FSW) is a solid state joining process used to join metals and their alloys. The main goal of this paper was to select the optimal welding parameters such as: rotational speed and the feed rate of the tool. The article presents the results of the tests on welding 1 mm thick 2024 aluminum sheet according to the statistical 3-level completed plan PS/DK 32. The rotational speed of the tool varied within the range of 1100–1300 rpm and the feed rate within the range of 40–60 mm/min. For these parameters, the analyses of the experiment repeatability, impact significance and adequacy of equations were conducted.

6

Evaluation of outsourcing transportation contract using simulation and design of experiment

Setamanit S.

Polish Journal of Management Studies

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2018

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Vol. 18, No. 2

300--310

EN

This paper aims to develop an approach to identify optimal fleet size under uncertainty and to identify important factors affecting transportation performance. The methodologies used in this paper are two folded. The first methodology is to develop a simulation model that allows manager to evaluate the impact of having different number of trailers on delivery and cost in order to identify the optimal fleet size. The second methodology is to use a Design of experiment (DOE) together with the simulation model to identify important factors that affect transportation performances. The result shows that the company should hire 16 trailers, which will reduce the delivery delay from 14% to 0.02%. Furthermore, it is found that variation in demand has a strong impact on late delivery and cost. There is also an interaction between demand variation and transportation time variation.

PL

Niniejszy dokument ma na celu opracowanie podejścia do określania optymalnej wielkości floty w warunkach niepewności oraz określenie ważnych czynników wpływających na wydajność transportu. Metodologie stosowane w tym artykule są złożone. Pierwszą metodologią jest opracowanie modelu symulacyjnego, który umożliwi menedżerowi ocenę wpływu posiadania różnych przyczep i kosztów w celu określenia optymalnego rozmiaru floty. Drugą metodologią jest wykorzystanie projektu eksperymentu (DOE) wraz z modelem symulacyjnym w celu zidentyfikowania ważnych czynników wpływających na wydajność transportu. Wynik pokazuje, że firma powinna wynająć 16 przyczep, co zmniejszy opóźnienie dostawy z 14% do 0.02%. Ponadto stwierdzono, że zróżnicowanie popytu ma duży wpływ na opóźnienia w dostawie i koszty. Istnieje również interakcja między zmiennością popytu a zmiennością czasu transportu.