Ch. Ratnam

Multi-response optimization in orthogonal turn milling by analyzing tool vibration and surface roughness using response surface methodology:

Turn milling is one of the machining processes used to mill circular work pieces while the work piece rotates about its own axis. Orthogonal milling is one of the turn milling processes where the bottom part of cutter removes material from the rotating work piece with high metal removal rate. In this article, tool condition was studied by analyzing surface roughness and vibration of cutter with the use of response surface methodology. According to design of experiments, 16 experiments were conducted on ASTM B139 phosphor bronze with high-speed steel end mill cutter on four-axis milling machine. The response surface methodology was used to find out significant parameters that are affecting surface roughness and amplitude of cutter vibration. A multi-response optimization technique was used to identify optimum cutting parameters for less surface roughness and amplitude of cutter vibration.

Investigation of reconfiguration effect on makespan with social network method for flexible job shop scheduling problem

Abstract This paper presents a novel social network analysis based method (SNAM) to evaluate the reconfiguration effect i.e., identification of key machines and their influence on the system performance in the context of Flexible job shop scheduling problem (FJSSP). This research formulates a mathematical model along with the constraints by incorporating the total completion time of jobs as an objective function. The proposed SNAM has been applied to generate the collaboration networks by transforming the input data and presenting them in the form of an affiliation matrix to the network analysis software. Thereafter, to analyze the collaboration networks various SNA measures that have been calculated and different functional properties are evaluated. Finally, to investigate the reconfiguration effect on makespan integration of process planning and scheduling (IPPS) has been implemented with adopted effective game theory based hybrid deoxyribonucleic acid (DNA) algorithm. The validation of the proposed approach and its effectiveness is conducted through comparisons with benchmark instances and results confirm the efficiency of the proposed approach.

Vibration Based Damage Identification Using Burg's Algorithm and Shewhart Control Charts

This paper proposes a methodology for the health monitoring of structures capable of identifying the damage at the earliest possible stage using the acceleration time response data obtained from piezoelectric accelerometers. In this, a unique combination of databased models to extract the damage sensitive features and Shewhart control charts to monitor the variations of the selected damage sensitive features are presented. The applicability of the proposed method is tested with the welded structure model by fixing it to the multi axes electro dynamic vibration shaker. In this, damage will be defined as a crack through the thickness of the weld and damage was introduced into the structure by cutting a slot in the weld using electric discharge machining. The acceleration time response data from the test structure are measured for five damage levels. Damage sensitive features are extracted by fitting a time prediction databased model called an Auto Regressive model to the measured acceleration time response data obtained from the undamaged structure. Then, the residual errors are calculated at each time step. To monitor the variation of mean and standard deviation of the extracted damage sensitive features, X-bar and S control charts are used. It is found that X-bar and S charts are capable of identifying the presence of damage for different damage levels considered in this work.

Selection of optimal performance parameters of DI diesel engine using Taguchi approach

ABSTRACT The design of experiments (DOE) is a systamatic method to determine the relationship between factors and output process. The Taguchi technique is the most important approach for evaluating the performance and emissions characteristics of a diesel engine. Input factors such as load, percentage of Karanja oil methyl ester (KOME) blend, compression ratio (CR), injection pressure (IP) and injection timing (IT) were considered. In order to evaluate the brake specific fuel consumption (BSFC) and exhaust emissions such as carbon monoxide (CO) and smoke using Signal to noise ratio(S/N) and Analysis of varience (ANOVA). The confirmation experiment was conducted to verify the results.

Shock and Vibration Prevention Using Angular Mounts with Different Types of Oil-Based Elastomers

In this article, S&V (‘shock and vibration’) angular mounts are utilized to condense transmitted sound vibration of different machinery and safeguard the equipment against submerged explosion. Getting the purpose of having a noiseless ship is workable, if the machines fitted on these ships are also noiseless and their vibrations are isolated. This can be accomplished through legitimate condition-monitoring of suitable vibration isolation mounts. For this, numerous mounts are used in diesel engines on board ships. To get the better durability of engines’ life and other running machines, both elastic and viscous (damping) elastomers are distinctive material that makes it useful for preparing vibration mounts. Here different types of oil-based elastomers are used as a vibration-absorbing part in mounts as it can be designated to get better dynamic properties. Utilizing the tentatively assessed estimations of the elastomeric damping and mount stiffness, the tested spring-mass model of the dynamic reaction utilizing an elastomeric angular mount as the versatile component can be precisely recreated. In this distinction, it is found that the single DOF of perfect spring-mass model utilizing steady damping and stiffness values be able to anticipate the response reaction of the system exactly at resonance except not at non-resonance frequencies. The method proposed is compared and validated by its experimental results.