Search

Spherical fuzzy sets are a broader type of fuzzy sets that have the ability to handle various scenarios using their membership, non-membership, and neutral membership grades. These sets require that the total of the squares of these grades be no greater than one. This condition extends the possible values for the three grades and enables decision makers to have a wider range of options when assessing a situation. In solving real-life problems, it is necessary to describe a real number as a spherical fuzzy set to incorporate the fuzziness; thus, the need to use trapezoidal spherical fuzzy numbers (TSFN). This paper discusses the membership functions of the TSFN, their arithmetic operations, and their properties. Also, a ranking function is proposed to order the TSFNs. All these are used to solve a fuzzy risk analysis problem whose parameters are presented as TSFNs. [ABSTRACT FROM AUTHOR]

High-density polyethylene (HDPE) was graft functionalized with two different mercaptoesters in an inert atmosphere at 160°C under different experimental conditions by thermolysis method. The order of functionalization, crosslinking, and C=C formation reactions were determined from the relative intensities of carbonyl stretching vibration and C--H bending vibrations. FTIR, DSC, and TGA analytical tools were used to characterize mercaptoester-functionalized HDPE. A plausible reaction mechanism is proposed here to explain the experimental results obtained. POLYM. ENG. SCI., 50:474-483, 2010. [C]2009 Society of Plastics Engineers, INTRODUCTION Polyethylene (PE), an important engineering material, is used in day to day life in many ways as plastic carry bags, toys, and other usable things. Unfortunately, because of the [...]

Byline: V. Dhanalakshmi, K. Sankaranarayanasamy, Subramaniam Arunachalam, S.C.Lenny Koh Agile manufacturing is an emerging concept in industry that aims at achieving flexibility and responsiveness to the changing market needs. The agility concept has an impact on design of products and control of manufacturing systems. Most research on Design For Assembly (DFA) has focused on single product rather than multiple products. In the design of a multiproduct assembly line, the flow of products is an important factor to be considered. Out of the five types of flow, the backtracking flow is the least desirable because it complicates the flow and the serial flow is the most desirable flow since it eases control of manufacturing and material handling. In this paper, an algorithm is developed to identify and to eliminate the critical pair, which causes backtracking. The algorithm can be used by the designers, in design and redesign of products, in simplifying the production flow and hence in improving the manufacturing performance.

Byline: V. Dhanalakshmi, K. Sankaranarayanasamy, Subramaniam Arunachalam, S.C. Lenny Koh The manufacturing information for a part is required for automated process planning, the link between CAD and CAM. Extraction of manufacturing features for a part from its CAD model is the first step in automated process planning. Most of the CAD models are transferred from one system to another through the neutral file format IGES. The software developed in C++ extracts both simple and concatenated features for prismatic parts from IGES files. The final results obtained are a set of manufacturing features along with their dimensions and positions, which can be used directly for downstream applications such as process planning, NC part programming and cutter path generation. The working of the system and algorithms used for feature extraction are explained with examples.

Aluminum-based metal matrix composites (AMCs) play a vital role for potential applications in aerospace and automotive industries. This paper explores the experimental analysis of a composite with aluminum LM4 alloy as the matrix and tungsten carbide (WC) as the reinforcement material. The composite specimens were fabricated by the stir casting process. The reinforced ratios of 5, 10 and 15 wt.% of WC particulates were stirred in molten aluminum LM4 alloy (AALM4). Once the composite is solidified, the specimens are prepared to the required ASTM dimensions and tested for various mechanical properties such as tensile strength, impact strength and hardness. Moreover, the tribological behavior of the composite was studied using the pin-on-disc wear test apparatus. X-ray diffraction (XRD) analysis was conducted to analyze the various elements present in the composites. Finally, the scanning electron microscope (SEM) analysis reveals the uniform distribution of WC particles in Aluminum LM4 alloy matrix. The improvement in mechanical properties - hardness, impact strength and tensile strength - was achieved for the increase in the addition of wt.% of WC particles in the LM4 matrix. The decrease in mass loss was observed for the composite containing 15 wt.% of WC during the wear test among the various composites tested. [ABSTRACT FROM AUTHOR]