Wyniki wyszukiwania - BazTech

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Modeling and optimization of cutting parameters when turning EN-AW-1350 aluminum alloy

Khrouf F., Tebassi H., Yallese M. A., Chaoui K., Haddad A.

International Journal of Applied Mechanics and Engineering

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2022

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Vol. 27, no. 2

124--142

EN

An experimental investigation is carried out to examine the effects of various cutting parameters on the response criteria when turning EN-AW-1350 aluminum alloy under dry cutting conditions. The experiments related to the analysis of the influence of turning parameters on the surface roughness (Ra) and material removal rate (MRR) were carried out according to the Taguchi L27 orthogonal array (313) approach. The analysis of variance (ANOVA) was applied to characterizing the main elements affecting response parameters. Finally, the desirability function (DP) was applied for a bi-objective optimization of the machining parameters with the objective of achieving a better surface finish (Ra) and a higher productivity (MRR). The results showed that the cutting speed is the most dominant factor affecting Ra followed by the feed rate and the depth of cut. Moreover, the Artificial Neural Network (ANN) approach is found to be more reliable and accurate than its Response Surface methodology (RSM) counterpart in terms of predicting and detecting the non-linearity of the surface roughness and material removal rate mathematical models. ANN provided prediction models with a precision benefit of 8.21% more than those determined by RSM. The latter is easier to use, and provides more information than ANN in terms of the impacts and contributions of the model terms.

2

Optimisation of water distribution networks design by minimizing the total length

Lahiouel Y., Chaoui K., Khezzar L., Haddad A., Azari Z.

Engineering Transactions

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2005

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Vol. 53, iss. 2

165-183

EN

The aim of the present work is to establish a new algorithm for the optimization of the design of water distribution networks. The proposed algorithm makes it possible to connect the nodes and the sources using the shortest path to obtain a final looped configuration. A novel method, the "minimal length algorithm", is proposed. It uses the advantages of existing methods and exceeds their limitations. Some of the well-known existing methods are the shortest path algorithm, the minimum spanning tree algorithm and a novel method published previously. The developed algorithm is implemented into a user-friendly interactive computer program which allows the design of looped systems with minimal length ensuring least cost, reliability of the network and hence the availability of water.

3

Dependence of the striking distance on earth electrode shape: a laboratory investigation

Boudissa R., Haddad A., Baersch R., Belaicha R.

Archives of Electrical Engineering

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2005

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Vol. 54, nr 2

127-142

EN

The electrogeometric model is now widely used for the dimensioning of lightning protection systems of ground structures. This model has the advantage of taking into account the magnitude of the lightning current and its statistical distribution but has a weakness in that it does not include the shape of electrode of the ground structure. This paper describes a laboratory experiment to investigate the dependence of the striking distance of a descending negative discharge on the shape of the ground electrode/structure. A theoretical study, based on the Lemke streamer-leader model, is also described. In this study, the streamer discharge is assumed to grow into a stable leader in the space between two electrodes when the streamer reaches a critical length, associated with the shape and polarity of the energized electrode. The experimental model uses an air-water interface in which the water conductivity is varied. The experimental results agree with the theoretical predictions.

PL

W projektowaniu układów ochrony odgromowej budowli naziemnych wykorzystuje się szeroko modele elektryczno-geometryczne. Ich zaletą jest możliwość uwzględnienia wartości prądu wyładowania i jego rozkładu statystycznego, wadą - niemożliwość analizy wpływu kształtu elektrod uziemieniowych. Artykuł przedstawia badania laboratoryjne zależności długości drogi przeskoku udaru o biegunowości ujemnej od kształtu elektrody uziemieniowej. Przedstawiono również analizę teoretyczną problemu w oparciu o model strimerowo-liderowy Lemkego. W analizie tej założono, że wyładowanie strimerowe przechodzi w ustabilizowane wyładowanie liderowe w przestrzeni międzyelektrodowej gdy strimer osiąga długość krytyczną, zależną od kształtu i biegunowości elektrody uziemieniowej. W modelu laboratoryjnym wykorzystano układ woda-powietrze ze zmienną konduktywnością cieczy. Wyniki badań laboratoryjnych są zgodne z analizą teoretyczną.