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A Genetic Algorithm for Structural Comparison
in the Fleet of Gear Trains
-- A B Srinivasa Rao, M Sreenivasa Reddy and A M K Prasad
It is desirable to know the characteristics inherent to the structure, so that the best train can be selected from the numerous distinct gear trains with the same number of links and degree of freedom. To achieve this, quantitative measures are developed in a simple way, using some of the principles of genetic process. These can be used for identifying a distinct train and to know the general characteristics of a gear train like speed ratio, transmission efficiency, etc. © 2011 IUP. All Rights Reserved.
Deflection and Stresses in Heavy Propeller
Shafts Considering Deformation of Bushed Bearings
and Foundation Bolts
--Kartikeya Tripathi and Vikrant Kulthe
In marine applications, high torque is transmitted by propulsion shafts. These shafts are long and supported on intermediate bearings, mounted on supports using bolts. The supports are fixed on ship hull. Such shafts sag under heavy load, resulting in large deflections and induced stresses. When the deflection and stresses are calculated using classical beam theory, it is not possible to account for deformation of bearings, bolts and compliance of base. In this paper, an analysis is done using finite element method by which such factors can be taken into account. The results are compared with those obtained using the classical theory. The method of analysis and the results should be useful in estimating the deflections and stresses in heavy and long shafts with better accuracy. This approach should also be useful in estimating the possibility of failure due to excessive stresses and deflections during mounting and assembly of such shafts. © 2011 IUP. All Rights Reserved.
An Application of Inner Product
of Vectors for Selecting Suitable Material
-- Senthil S
A component is made up of different materials. Material selection is a step in the process of designing any physical object. Today, a variety of materials are available, with each material having its own characteristics, applications, advantages and limitations. Designers have to consider a large number of material selection attributes. An improper selection will affect the productivity and profitability of a firm. Material selection is a multicriteria decision-making problem involving a large number of attributes. A systematic and efficient approach to material selection is necessary in order to select the best alternative for a given application. In this paper, an Inner Product of Vectors (IPV) method is proposed. The procedure is based on an IPV method considering the material selection attributes and their relative importance for the application considered. An example is taken to validate and demonstrate the proposed method. © 2011 IUP. All Rights Reserved.
Effect of Tool Geometry on Joint Properties
of Friction Stir Welded Al/Cu Bimetallic Lap Joints
-- M Satya Narayana Gupta, B Balunaik and K G K Murti
Friction Stir Welding (FSW) is an emerging solid state welding method which is finding increasingly widespread industrial acceptance for joining similar and dissimilar materials. Aluminium to copper bimetallic lap joints have got wide acceptance in the electrical and electronic industries. Commercially, pure Al/Cu bimetallic lap joints are fabricated by the FSW technology using tapered and straight fluted tools. This paper presents valuable information on electromechanical behavior of aluminium to copper bimetallic lap joints required for critical applications such as high current busbars, heavy duty earthing strips, etc. The experiments are conducted based on Design of Experiments (DoE) to reduce the number of trials. It is observed that better joint properties are obtained in the joints fabricated using straight fluted tool and the joint resistance is negligible, as in manufactured condition. © 2011 IUP. All Rights Reserved.
A Study of Semi-Automated Speed Controlling Device
for Wood Machining
-- R V Praveena Gowda, A N N Murthy and E Muniraju
When the cutter comes in contact with the material, the speed of a cutter suddenly drops due to the hardness of the material. This causes various problems such as the reduction in the tool life, more power consumption and so on. The objective is to control the speed of the cutter depending on the hardness of the material. So, to overcome the above problem, a semi-automated speed controlling device for machine tools was designed to vary the speed of the cutter with a constant feed rate of the job depending on the hardness and strength of the material. This prototype is concerned with the machining of different types of wood. It consists of a 1 HP variable speed DC motor, Tachogenerator, 8’’ tungsten carbide tip cutter, and a motor for the automatic feeding mechanism. The project is concerned with the study of existing methods of machining, finding alternate techniques for the speed control, pilot study of a new machine, cost analysis and designing the prototype. Finally, the field testing was done keeping the few constraints in view. After testing, it was observed that the power utilization in the designed machine reduced by about 42%. Tool life would also be increased and the property of the material (job) would not be hindered due to the heat generated between the job and the cutting tool. It is the effective implementation of the semi-automatic machine for cutting which would give enormous benefits in the field of power utilization and tool life. A few modifications like Proportionate Integrate Delivery (PID) system technology are also required for the better use of the machine tool in cutting. © 2011 IUP. All Rights Reserved.
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