Shyam Prasad Kodali - Academia.edu (original) (raw)

Papers by Shyam Prasad Kodali

Structural integrity of engineering materials is influenced by external as well as internal defec... more Structural integrity of engineering materials is influenced by external as well as internal defects. Tomographic reconstruction is useful for detection of internal defects in a nondestructive way. A novel tomographic reconstruction procedure is described and shown to have the potential to identify any defects present in a materials cross-section. The algorithm is designed in line with the principles of real coded genetic algorithms (RCGA). The proposed algorithm does not require the user to input exact characteristic property of material defects assumed to be present in the material cross-section being examined. The algorithm works its way with some finite range of the characteristic property as input. Results of several numerical studies demonstrate the effectiveness of proposed RCGA based reconstruction procedure.

Lecture Notes in Mechanical Engineering, 2021

Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbi... more Turbomachines are machines that transfer energy between a rotor and a fluid, including both turbines and compressors. While a turbine transfers energy from a fluid to a rotor, a compressor transfers energy from a rotor to a fluid. Many different designs of turbomachines are in use of which Tesla turbomachine is one, whose design is different from conventional designs. A Tesla turbomachine utilizes the viscous shear forces of a fluid (boundary layer effect) passing near a disk on an axle to transmit torque to and from the fluid. Tesla turbomachines have found wide ranging applications that include handling of mixtures of solids, liquids and gases without damaging the machine. It can be designed to efficiently pump highly viscous fluids as well as low viscous fluids. It has been used to pump fluids including ethylene glycol, fly ash, blood, rocks, live fish and many other substances. This paper attempts to present the outcomes of research carried out by various researchers during the ...

Knowledge-Based Systems, 2012

The development of an expert system for abrasive water jet machining (AWJM) process is considered... more The development of an expert system for abrasive water jet machining (AWJM) process is considered in the present work. The expert system has been developed by using fuzzy logic (FL). It is to be noted that the performance of AWJM in terms of depth of cut depends on various process parameters, such as diameter of focusing nozzle, water pressure, abrasive mass flow rate and jet traverse speed. Three approaches have been developed to predict the depth of cut in AWJM using FL system. The first Approach deals with the construction of Mamdani-based fuzzy logic system. It is important to note that the performance of the FL depends on its knowledge base. In Approach 2, the data base and rule base of the FL-system are optimized, whereas in the third Approach, the total FL-system is evolved automatically. A binary-coded genetic algorithm has been used for the said purpose. The developed expert system eliminates the need of extensive experimental work, to select the most influential AWJM parameters on the depth of cut. The performances of the developed FL-systems have been tested to predict the depth of cut in AWJM process with the help of test cases. The prediction accuracy of the automatic FL-system (i.e. Approach 3) is found to be better than the other two approaches.

Lecture Notes in Computer Science, 2009

Results of simulation studies on the application of genetic algorithms (GA) for solving an invers... more Results of simulation studies on the application of genetic algorithms (GA) for solving an inverse problem, tomographic reconstruction, using time-of-flight (TOF) data from ultrasound transmission tomography are presented. The TOF data is simulated without taking into consideration the diffraction effects of ultrasound which is reasonably valid when the impedance mismatch in the specimen under consideration is small. The proposed GA based reconstruction algorithm is described and the results for a number of cases are discussed. The sensitivity of the proposed algorithm is studied for various GA parameters viz. the population size, maximum number of generations, crossover probability, and mutation probability. A time complexity analysis of the proposed algorithm shows that the reconstruction times and number of unknowns bears a near quadratic relation enabling the prediction of reconstruction times when dealing with higher resolutions. The performance of proposed algorithm to the reconstruction when TOF data is contaminated with noise is also analyzed and presented. The results obtained are found to be consistent for a wide range of resolutions, type, size, and shape of inclusions.

In this work re-engineering approach has been used to determine the design concept of an accelera... more In this work re-engineering approach has been used to determine the design concept of an acceleration pedal and structural steel material had been used at this stage for analysis purpose. Various designs had been tried to reduce deformation in this acceleration pedal. In this particular design Catia software is used at the design stage and for analysis, Ansys 17.2 had been used.The Same metal had been selected for both the pedals in order to compare the results between them. Deformation results are achieved on Ansys. The result reveals that remodeled design has better results than the existing pedal. The pedal deformation is reduced comparatively up to 12%.

Engineering materials and structures have crack-like defects leading to premature failures. Usage... more Engineering materials and structures have crack-like defects leading to premature failures. Usage of fracture mechanics to assess the structural integrity requires knowledge on the type, location, shape, size, and orientation of the flaws. Tomographic reconstruction is one of the commonly used nondestructive testing methods for flaw characterization. The cross sectional image of the object being tested is obtained through the application of various reconstruction methods that are categorized as either analytical methods or iterative methods. In this work an iterative algorithm that works on the principles of genetic algorithms is developed and used for the reconstruction. The results of simulation studies on the tomographic reconstructions using genetic algorithms for the identification of defects in isotropic materials are discussed in the paper. The solution methodology based on use of genetic algorithms is applied to reconstruct the cross sections of test specimens with different...

Lecture Notes in Mechanical Engineering

These days it is very common to see many cars, from passenger cars to sports cars fitted with dif... more These days it is very common to see many cars, from passenger cars to sports cars fitted with different kinds of spoilers on them. It is well known that external aerodynamics of a car is the key to better performance and comfort levels. In view of this, besides other factors, all car manufacturers' aim at an optimized car design in terms of external aerodynamics of the car. The addition of rear spoiler to an aerodynamically optimized car body will result in a change of lift and drag forces the car experiences and thus influence the cars overall performance, fuel consumption, safety, and stability. The paper presents a discussion on the results obtained from numerical simulation of airflow over a passenger car without a rear spoiler and compares these with results obtained for a passenger car fitted with a rear spoiler. The influence of rear spoiler on the generated lift, drag, and pressure distributions are investigated and reported. The approach followed is "model-mesh-ana...

Materials Today: Proceedings

Multidiscipline Modeling in Materials and Structures

Purpose The purpose of this paper is to adopt the multi-objective optimization technique for iden... more Purpose The purpose of this paper is to adopt the multi-objective optimization technique for identifying a set of optimum abrasive water jet machining (AWJM) parameters to achieve maximum material removal rate (MRR) and minimum surface roughness. Design/methodology/approach Data of a few experiments as per the Taguchi’s orthogonal array are considered for achieving maximum MRR and minimum surface roughness (Ra) of the Inconel718. Analysis of variance is performed to understand the statistical significance of AWJM input process parameters. Findings Empirical relations are developed for MRR and Ra in terms of the AWJM process parameters and demonstrated their adequacy through comparison of test results. Research limitations/implications The signal-to-noise ratio transformation should be applied to take in to account the scatter in the repetition of tests in each test run. But, many researchers have adopted this transformation on a single output response of each test run, which has no ...

Proceedings of the Eleventh Conference on Congress on Evolutionary Computation, May 18, 2009

ABSTRACT Different approaches are in use to solve the problem of tomographic reconstruction, whic... more ABSTRACT Different approaches are in use to solve the problem of tomographic reconstruction, which is an inverse problem. Four different approaches; three variations of multiplicative algebraic reconstruction technique (MART) and a new approach based on genetic algorithms (GA), are evaluated and compared in the paper. The approaches are applied to the reconstruction of specimens from time-of-flight data collected by ultrasound transmission tomography. The time-of-flight data is simulated without taking into consideration the diffraction effects of ultrasound which is reasonably valid, only when the impedance mismatch in the specimen under consideration is small. Also it is assumed that the specimen under consideration consists of a maximum of three different materials with the goal being to identify the number, shape, and location of the inclusions in the specimen. The sensitivity of the various algorithms to the parameters involved, performance of various algorithms in terms of errors in reconstruction and time taken for the reconstruction are studied and presented here. Further the performance of the algorithms when the input data are contaminated with noise is presented. It is observed that although GA takes more time than MART, GA is reliable and accurate and scores much better than MART in dealing with problems where only limited data is available for the reconstruction.

International Journal of Modeling, Simulation, and Scientific Computing, 2010

In the present study, forward modeling of high-speed finish milling process has been solved using... more In the present study, forward modeling of high-speed finish milling process has been solved using soft computing. Two different approaches, namely neural network (NN) and fuzzy logic (FL), have been developed to solve the said problem. The performance of NN and FL systems depends on the structure (i.e. number of neurons in the hidden layer, transfer functions, connection weights, etc.) and knowledge base (i.e. rule base and data base), respectively. Here, an approach is proposed to optimize the above-mentioned parameters of NN and FL systems. A binary coded genetic algorithm (GA) has been used for the said purpose. Once optimized, the NN and FL-based models will be able to provide optimal machining parameters online. The developed approaches are found to solve the above problem effectively, and the performances of the developed approaches have been compared among themselves and with that of the results of existing literature.

2009 IEEE Congress on Evolutionary Computation, 2009

Proceedings of the 10th annual conference on Genetic and evolutionary computation - GECCO '08, 2008

In this paper simulation studies of the ultrasound computerized tomography (CT) technique employi... more In this paper simulation studies of the ultrasound computerized tomography (CT) technique employing time of flight data is presented. An enhanced genetic algorithm based reconstruction technique is proposed that is capable of detecting multiple types of inclusions in the test specimen to be reconstructed. It is assumed that the physical properties of the inclusions are known a priori. The preliminary results of our algorithm for a simple configuration are found to be better than those reported with MART1. In addition to being able to identify inclusions of different materials, both the shape and location of the inclusions could be reconstructed using the proposed algorithm. The results are found to be consistent and satisfactory for a wide range of grid sizes and geometries of inclusion(s). Based on the regression analysis an empirical relation between the number of unknowns and the reconstruction time is found which enables one to predict the reconstruction time for higher resolutions.

2008 First International Conference on Emerging Trends in Engineering and Technology, 2008

Abstract The selection of optimum machining parameters in any machining process involves multiple... more Abstract The selection of optimum machining parameters in any machining process involves multiple conflicting objectives and often solution to such problems is sought by converting them into a single composite objective. In this paper a truly multi-objective optimization of ...

SN Applied Sciences

Metal matrix composites are extensively used in aerospace, automobile and other engineering appli... more Metal matrix composites are extensively used in aerospace, automobile and other engineering applications as an alternative to a wide range of elements. High strength-weight ratio, durability and high corrosion resistance are benefits of metal matrix composites. The study that exhibits adopts optimal cutting parameters (speed, feed and depth of cut). The initial study is to explore end milling process of alumina (AA6082 with SiC 3% and fly ash 2%) molted metal matrix composite. The technique for order preference by similarity to ideal solution and fuzzy logic for optimizing the cutting parameter values has been utilized in the MMC. The response surface methodology is being used to develop the numerical model between output responses and machining parameters. The second-order regression models are studied through analysis of variance. The experimental investigation exhibits that feed rate is the important factor on response variables.