Wyniki wyszukiwania - Biblioteka Nauki

1

Dry Sliding Friction and Wear Behaviour of Leaded Tin bronze for Bearing and Bushing Application

100%

Dinesh D. , Megalingam A.

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2021

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tom Vol. 66, iss. 4

1095--1104

EN

Among different bearing materials, copper-based alloys are the most important source for bearing and bushing applications. In this work, the tribological behavior of a leaded tin bronze (Cu-22Pb-4Sn) against an EN31 Steel for various loads (20 N, 70 N, 120 N) and different sliding velocity (1 m/s, 3 m/s, 5 m/s) at 3000 m sliding distance is performed using a pin on disk tribometer. Irrespective of all loads and sliding velocity, a higher specific wear rate is observed at 1 m/s and 120 n that fails to facilitate the formation of lubricating film, whereas a lower specific wear rate is evident when the sliding velocity is increased to 5 m/s. This is attributed to the formation of a stable oxide layer that has been confirmed through the energy dispersive X-ray spectroscopy analysis and scanning electron microscopy. The coefficient of friction is observed in reducing trend from 0.69 to 0.48 for the increasing load (70 N, 120 N) and sliding velocity (3 m/s and 5 m/s) due to stable thin oxide film formation. Also, the increase in frictional force and loading the interacting surface temperature is increased to a maximum of 102°C. The grey relational analysis indicates that the optimal parameters for the minimum specific wear rate and coefficient of friction is 120 N and 5 m/s that has been confirmed with experimental analysis.

2

Optimization of the sizing process with grey relational analysis

86%

Sarpkaya C. , Sabir E. C.

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2016

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tom Vol. 24, no. 1 (115)

49--55

EN

The sizing process is an important one for textile mills and affects the efficiency of the loom machine. In this study, the optimization of multiple performance characteristics based on the grey relations analysis method, which is a new approach for optimization of the sizing process was researched using the Taguchi L18 (mixed 3 - 6 level) experimental plan. The process parameters selected: warp yarn count, the viscosity of the sizing solution and the dispatch speed of the warp yarn passing from the sizing machine, were optimized. In the experimental design of Taguchi L18 (mixed 3 - 6 level), the warp yarn count factor was chosen as 3 levels (12, 10 and 8 tex), the viscosity of the sizing solution factor as 3 levels (14, 20, & 24 Ns/m2), and the dispatch speed of the warp yarn passing from the sizing machine factor was selected as 6 levels (40, 50, 60, 70, 80, & 90 m/min). Quality characteristics were determined as the warp yarn strength, and the efficiency of the loom machine. A grey relational grade obtained from the grey relational analysis is used to solve the sizing process with multiple performance characteristics. Optimum levels for the sizing process parameters were determined using the grey relation grade.

PL

Proces nanoszenia preparacji jest ważny w procesie produkcji tkanin i wpływa na wydajność stosowanych krosien. Przeprowadzono optymalizacje szeregu parametrów procesu stosując metodę analizy zbiorów rozmytych będącą nowością w analizie procesu nanoszenia preparacji . Wykorzystano plan Tagucchi dla realizacji eksperymentu. Analizę przeprowadzono dla trzech przędz o różnych masach liniowych, trzech różnych lepkościach roztworu preparacji i trzech różnych prędkościach osnowy przechodzącej przez urządzenie do preparacji. Określono charakterystykę jakościową biorąc pod uwagę wytrzymałość osnowy i wydajność krosna. Optymalne wartości parametrów procesu preparacji określono przy zastosowaniu metody zbiorów rozmytych.

3

Study on an Optimal Design of Mechanical Properties for PP/PET Nonwovens

72%

Su T. L. , Gui-Bing H.

Fibres & Textiles in Eastern Europe

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2012

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tom Vol. 20, no. 5 (94)

75--79

EN

This study aimed to determine the optimal process parameters of needle-punched nonwoven fabrics, and obtain the maximal strength of needle-punched nonwoven fabrics. The Taguchi approach and grey relational analysis were used to solve the multi-quality optimisation problem and determine the optimal process parameter combination of needlepunched nonwoven fabrics. The L9 orthogonal array was used to design parameters that affect the needle-punched nonwoven fabric process, including the folding machine oscillating speed, folding machine conveying speed, needle-punch depth, and needle-punch density. Then grey relational analysis was used to overcome the single quality characteristic disadvantage of the Taguchi approach, and the optimal process parameter combination of multiple quality characteristics was obtained from the response graph of the analysis. The quality characteristics of this experiment are the nonwoven fabric tearing strength and tensile strength. Signal-to-noise ratios (S/N ratio) were calculated and an analysis of variance (ANOVA) was conducted to analyse the experiment results. The results of ANOVA showed that the factors with a significant effect on the quality characteristics of needlepunched nonwoven fabrics included the needle-punch depth and needle-punch density. In other words, by controlling these factors the quality characteristics of the needle-punched nonwoven fabrics could be controlled effectively. Finally, the 95% confidence interval of the verification experiment proved that this experiment was reliable and reproducible

PL

Celem pracy było wyznaczenie optymalnych parametrów procesu, otrzymywanie włóknin igłowanych dla uzyskania optymalnych właściwości, w tym możliwie jak największej wytrzymałości mechanicznej. Zastosowano metodę Taguchi i analizę zbiorów rozmytych. Jako parametry wyjściowe przyjęto: prędkość oscylacji maszyny igłującej, szybkość transportową, głębokość igłowania oraz gęstość przeigłowań. Optymalizację przeprowadzano pod kątem uzyskania maksymalnej wytrzymałości włókniny oraz odporności na rozrywanie. Przy analizie określano poziom szumów sygnału oraz przeprowadzono analizę wariancji. Stwierdzono, że najistotniejszymi parametrami, które muszą być kontrolowane w czasie produkcji włókniny są głębokość i gęstość przeigłowań.

4

Hybrid GRA-PCA and modified weighted TOPSIS coupled with Taguchi for multi-response process parameter optimization in turning AISI 1040 steel

72%

Mst. Nazma S. , Nikhil Ranjan D.

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tom LXVIII, nr 1

23--49

EN

The objective of the present study is to optimize multiple process parameters in turning for achieving minimum chip-tool interface temperature, surface roughness and specific cutting energy by using numerical models. The proposed optimization models are offline conventional methods, namely hybrid Taguchi-GRA-PCA and Taguchi integrated modified weighted TOPSIS. For evaluating the effects of input process parameters both models use ANOVA as a supplementary tool. Moreover, simple linear regression analysis has been performed for establishing mathematical relationship between input factors and responses. A total of eighteen experiments have been conducted in dry and cryogenic cooling conditions based on Taguchi L18 orthogonal array. The optimization results achieved by hybrid Taguchi-GRA-PCA and modified weighted TOPSIS manifest that turning at a cutting speed of 144 m/min and a feed rate of 0.16 mm/rev in cryogenic cooling condition optimizes the multi-responses concurrently. The prediction accuracy of the modified weighted TOPSIS method is found better than hybrid Taguchi-GRA-PCA using regression analysis.