Advanced Materials Research Vols. 984-985

Abstract: Workability is a degree of the amount of deformation that a powder metallurgy bits and pieces can survive prior to fracture occurred in the forming or upsetting processes. Ductile fracture is the most general mode of breakdown in bulk forming process. The formability is a complicated happening, dependent upon the method as well as the material parameters. An investigational research work was performed for the kind of the working behavior of Al–SiC-Y2O3 hybrid composite under triaxial stress state circumstance. Upsetting of Al–SiC-Y2O3 powder metallurgy compacts with various aspect ratios and initial preform densities were carried out and the working behavior of the powder compacts at various state conditions was computed. In the powder metallurgy technique cold pressing can be used for compaction of the reinforcement of SiC and Y2O3 with Aluminum hybrid composites (Al+SiC+Y2O3). The bottle green compacts can be sintered and workability characteristics can be studied. In the hybrid composites, SiC content has been different from 0% to 20% with different particle sizes namely 60 and 80μm. Y2O3 nanoparticles of size 30-50nm and reinforced with 1wt% , 2wt% and 3wt%. The experimental Results can be analyzed for workability and frictional stress state conditions during upsetting as a role of relative density. The formability stress index values obtained for various addition of SiC and Y2O3.

Abstract: — Finite element formulation for Functionally Graded Material (FGM) square plates subjected to Thermal loads are presented. The plate is assumed to be having linear temperature rise through the thickness. The power law distribution model is assumed for the composition of the FGM material along the thickness. A software program “COMSAP” has been developed using Semiloof shell element formulation and validation checks are carried out using the results available in the related literature. Results for thermal stress and thermal buckling analysis of functionally graded plates are reported.

Abstract: Metal matrix composites possess some glamorous properties like light weight, low density ,high strength-to-density ratio, formable to complex shape, lower manufacturing cost and are used more in commercial, industrial, marine, naval based industrial and are extensively used in automobiles and aerospace like empennage, wings, fuselage in fighter aircraft, bomber, transport, general aviation, rotary aircraft etc. Many researches are done on micro structural metals matrix composites and they result shows that composite of micro structural having good mechanical properties. Instead of using micro structural nanoparticles are used for better mechanical properties and better applications in aeronautical field. The present study is an attempt to prepare and analysis of mechanical properties of Aluminium 6061 reinforcement with TiB₂ nanoparticles using liquid metallurgy. By the use of ball milling process the TiB₂ micro particles are converted in to nanoparticles and reinforced with Aluminium 6061 in stir casting process. The addition level of reinforcement is being varied from 0-15wt% in step of 4 wt%.Test carried out on the fabricated composite included scanning electron microscopy, XRD, EDAX analysis, and Thermal analysis.

Abstract: Arriving optimal solutions is one of the important tasks in engineering design. Many real-world design optimization problems involve multiple conflicting objectives. The design variables are of continuous or discrete in nature. In general, for solving Multi Objective Optimization methods weight method is preferred. In this method, all the objective functions are converted into a single objective function by assigning suitable weights to each objective functions. The main drawback lies in the selection of proper weights. Recently, evolutionary algorithms are used to find the nondominated optimal solutions called as Pareto optimal front in a single run. In recent years, Non-dominated Sorting Genetic Algorithm II (NSGA-II) finds increasing applications in solving multi objective problems comprising of conflicting objectives because of low computational requirements, elitism and parameter-less sharing approach. In this work, we propose a methodology which integrates NSGA-II and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) for solving a two bar truss problem. NSGA-II searches for the Pareto set where two bar truss is evaluated in terms of minimizing the weight of the truss and minimizing the total displacement of the joint under the given load. Subsequently, TOPSIS selects the best compromise solution.

Abstract: — This paper demonstrates to build a Fuzzy Inference System (FIS) for any model utilizing the Fuzzy Logic Toolbox graphical user interface (GUI) tools. A different conception for decision making process, based on the fuzzy approach, is propounded by authors of the paper.The paper is worked out in two sections. Description about the Fuzzy Logic Tool box is done in the first section.Illustration with an introductory example concludes the second section. Based on various assumptions the authors construct the rule statements which are then converted into fuzzy rules and the GUI tools of the Fuzzy Logic Toolbox built using MATLAB numeric computing environment is used to construct a fuzzy inference system for this process.The output membership functions are expected to be fuzzy sets in Mamdani-type inference.Defuzzification of fuzzy set for each output variable generated after the aggregation process has to be carried out. Application of information technology for Decisions in today's environment which is highly competitive are undeniable principles of organizations and helps managers in making useful decisions meaningfully.

Abstract: In this paper finite element model of steel dental bracket is generated along with bonding agent, enamel & stress analysis is carried out on the bracket for different loading conditions. Three dimensional finite element model developed are constrained with boundary condition that resembles to the reality. The Vonmisses stress is recorded for each loading conditions and compared with experimental results. The experimental work for 60 samples were carried out on Universal testing machine at material testing laboratory, Basaveshwar Engineering College, Bagalkot. It is found from FEM results that the shear bonding strength for different loadings from 60 N to 80 N varies from 7.276 N/mm² to 9.7N/mm², which are closer to experimental values with acceptable error. The study reveals that Finite Element Method can be used as a strong tool to analyze the dental bracket and study different parameters to improve its performance and to avoid time and cost required for experimentation.

Abstract: Fixture layout design is crucial to ensure machining accuracy and sustained quality of manufacture. The machining accuracy can be improved by minimizing the workpiece deformation through proper positioning of the workpiece. Fixtures are employed to minimise the degrees of freedom of a workpiece during machining of objects where the positioning of fixture elements is crucial in minimizing the workpiece deformation. The main purpose of this research work is to perform static analysis on workpiece-fixture system involving drilling operation. Finite element method (FEM) has been used to model the workpiece-fixture system and determine the workpiece deformation. The positions of the locators and clamps are predicted using response surface methodology and the fixture optimized parameters are obtained by ant colony algorithm (ACA).

Abstract: The layout of a flexible manufacturing system (FMS) involves distributing different resources for achieving maximum efficiency. To provide a variety of products to customers the FMS has created a significant set of operational changes. Among this, layout planning is more important in achieving productivity of FMS. The problem of this type is combinatorial in nature and found to be Non-deterministic Polynomial (NP) complete. This paper focuses the loop layout planning of an FMS with the aim of minimizing the transportation distance and the backtracking distances of the Automated Guided Vehicles (AGV) using the hybrid Scatter Search - Particle Swarm Optimization algorithm (SS-PSO). Since the Loop layout has relatively low initial costs and contains few material handling links with higher flexibility. SS-PSO operates on unifying principles based on strategic designs compared to other metaheuristic algorithms such as GA, PSO etc. Hybrid SS-PSO approach is applied to seven and nine machines loop layout problem. It is found that the proposed algorithm provides a better solution with fast convergence rate compared with other metaheuristic algorithms.

Abstract: This journal describes a study on the structural effects of DI diesel engine conventional piston and modified pistons. To enhance the combustion efficiency of the engine conventional piston has been modified as shallow depth piston bowl with swirling grooves on the piston crown. Three different widths (5.5mm, 6.5mm and 7.5mm) and constant depth (0⁰ to 5⁰) swirling grooves added on the shallow depth combustion chambered piston crown. The conventional piston and modified pistons has been modeled in CATIA software and structural analysis done in ANSYS 14. In structural analysis observed that deformation for the modified pistons are same and negligible as compared to the conventional piston.

Abstract: – Pressure vessels often have a combination of high pressure together with high temperature such as gun barrels and high pressure hydraulic rams. For high pressure application, the cylindrical vessels are made to withstand the working pressure. These types of pressure vessels are made by two techniques, one is shrink-fit cylinders and other one is autofrettage cylinders. Autofrettage technique is used to ensure the pressure vessel highly strengthened due to prestressed effect causing the internal portion of the part to yield and resulting in internal compressive residual stresses. The present work is concerned about the elastoplastic stress analysis of thick cylinders. The numerical analysis is carried out on four different materials which are widely used in pressure vessels by using finite element software ANSYS. The elastic breakdown pressure, overstrain pressure, and bursting pressure of the cylinder are found out and the results are compared with experimental results.