Pardeep Gupta

Effect of Process Parameters on Kerf Width in WEDM for HSLA Using Response Surface Methodology

Wire electric discharge machine (WEDM) is a spark erosion machining process to cut very hard conductive material with the help of a wire electrode. High strength low alloy steel (HSLA) is a hard alloy with high hardness and wear resisting property. The purpose of this study is to investigate the effect of parameters on kerf width for WEDM using HSLA as workpiece. HSLA is used in cars, trucks, cranes, bridges, roller coasters and other structures that are designed to handle large amounts of stress. It is revealed that kerf width decreases with increase in pulse on time, pulse off time, spark gap voltage and peak current. Kerf width increases with increase in wire tension. In order to evaluate the effect of selected process parameters, the response surface methodology (RSM) is used to formulate a mathematical model which correlates the independent process parameters with the desired kerf width. The central composite rotatable design has been used to conduct the experiments. The analysis of results indicates that the spark gap voltage, pulse on time, peak current and pulse off time have a significant effect on kerf width.

Optimizing OEE, productivity and production cost for improving sales volume in an automobile industry through TPM: a case study

The aim of this paper is to investigate how increase in sales volume has evolved by improving overall equipment effectiveness (OEE) of machines, plant productivity and production cost through total productive maintenance (TPM) initiatives in a reputed tractors manufacturing industry in India. In the present scenario of global competitive market, the manufacturing industry needs to improve their operational performance for surviving and prospering. TPM is practised by industry as a business tool for rapid and continuous improvement in its manufacturing capabilities. OEE offers a powerful control tool to overcome production deficiencies and operational performance constrains. Productivity and manufacturing cost are also crucial operational measures to analyse the manufacturing performance. In this study, evaluation and analysis of the methodology adopted for improving sales volume through TPM initiatives was carried out using an interactive research approach. The industrial example on the application of OEE tool demonstrates that it has a remarkable potential to enhance the equipment effectiveness. The empirical findings of the study reveal that augmented OEE and productivity, and reduced production cost resulted to double the sales revenue and triple the profit within a period of three years. The industry also achieved notably tangible and intangible benefits with the TPM implementation.

System for computer-aided cavity layout design for die-casting dies

Die-casting is one of the methods used to produce a large number of components with a good surface finish by injecting cast alloys into a metal mould under high pressure. The design of a die-casting die requires human expertise and is normally performed by trial and error, which leads to monetary and time losses. Automation at the initial die design stage would result in higher productivity and would reduce the production lead time. Decisions regarding the number of cavities, the layout pattern and the placement of cavities in die-casting are critical for die design and manufacturing. This paper presents research work on a system for computer-aided cavity layout design for die-casting dies. The proposed system consists of three modules: (1) determination of number of cavities; (2) selection of layout pattern; and (3) placement of cavities in the die base. It enables die designers to generate a cavity layout design automatically from a computer-aided design (CAD) file of the part with little information provided manually. The optimal number of cavities is determined by considering economic, technical, geometrical and time limitations, followed by the selection of a layout pattern. Thereafter, cavities are placed in the die base. The developed system depends on a database of die-casting machines and materials along with a knowledge base of die design. This system has been tested on a number of die-casting parts and results have been found to be along the lines of those obtained by the industry. The proposed system is more comprehensive than those presently available and is a step in the right direction for design-manufacturing integration for die-casting.

Mission Reliability and Availability Prediction of Flexible Polymer Powder Production System

The expressions for mission reliability and steady state availability of flexible and complex polymer powder production system a part of acrylic fiber mill are derived. This practical paper explains mathematical formulation of the problem with more realistic and practical assumptions to evaluate reliability parameters of interest. The system under consideration is a complex and flexible mechanical system being used in a chemical plant manufacturing dry polymer powder from monomers. This is a multicomponent system and on failure of some of its units, this system remains operative for a short specified period of time. Here the mission becomes to repair these failed units within the specified repair time to run the system continuously, otherwise the system will transit to non-operative state. Failure rates for all the units are constant while their repair times are arbitrarily distributed. The problem is formulated using probability considerations and supplementary variable technique. Lagrange’s method for partial differential equations is used to solve the system governing equations.

A hybrid impedance control scheme for underwater welding robots with a passive foundation in the controller domain

A hybrid impedance control scheme for the force and position control of an end-effector is presented in this paper. The interaction of the end-effector is controlled using a passive foundation with compensation gain. For obtaining the steady state, a proportional–integral–derivative controller is tuned with an impedance controller. The hybrid impedance controller is implemented on a terrestrial (ground) single-arm robot manipulator. The modeling is done by creating a bond graph model and efficacy is substantiated through simulation results. Further, the hybrid impedance control scheme is applied on a two-link flexible arm underwater robot manipulator for welding applications. Underwater conditions, such as hydrodynamic forces, buoyancy forces, and other disturbances, are considered in the modeling. During interaction, the minimum distance from the virtual wall is maintained. A simulation study is carried out, which reveals some effective stability of the system.

Study of success factors of TPM implementation in Indian industry towards operational excellence: An overview

Presently the manufactures are facing a great pressure to reduce cost of manufacturing and provide new and quality products in the market on a regular basis. The Indias manufacturing sector is striving hard towards operational excellence. Reduction of waste, improvement of quality, higher through put and overall more efficient production system is leading India towards a manufacturing revolution. A good number of companies have started implementing a range of business strategies including going lean, and using manufacturing strategies such as TPM, TQM, Six Sigma, JIT etc. to obtain operational excellence. Total Productive Maintenance (TPM) refers to a management system for optimizing the productivity of manufacturing equipment. A study to evaluate the implementation aspects and success factors of TPM initiatives taken by Indian industry for achieving manufacturing excellence is carried out and presented in this paper. There remained considerable improvement in the morale of employees, skill level of employees, technological up-gradation, machine conditions, and customer satisfaction level after TPM. Also the industries remained successful in improving their overall equipment effectiveness (OEE) up to 30% and some of them achieved the world class level of 95% OEE.

A Brief Review on Modeling Approaches of Friction Dampers Used in Turbomachinery

The present paper deals with a brief review on different modeling techniques used to model friction dampers in turbomachinery. It is not the intention of the author to provide a detailed survey on all the approaches. However, the main concentration is on finite element modeling and bondgraph modeling. The main purpose of this paper is to provide a detailed survey on various modeling approaches adopted in turbomachinery, especially kinematics modeling, finite element modeling, parametric modeling, harmonic balance analysis and bondgraph modeling. The usefulness of bondgraph modeling technique is underlined in this paper presenting several considerations in the model. The bondgraph is one of the most convenient ways to represent a system form the physical aspects in foreground. It has advantages of putting together multi-energy domain of the system in a single representation in a unified manner. A case study of bondgraph modeling of turbine blade has been presented along with friction damper.

SCM: An integrated approach for effective management: A case study of manufacturing unit

In the present work the current supply chain of the company has been thoroughly studied to sort out the excess inventory related problem and a new model of supply chain of the company has been proposed with recommendations. A demand forecasting analysis has been done for solving inventory pileup problem in the store. The Bullwhip effect is quantified and recommendations are given to reduce variation in the demand and supply of company. To sort out problem of irregularities in the supply of raw materials a proper vendor rating method has been designed for the company and ABC analysis in the inbound store has been proposed to streamline the purchasing activity of the company. The bar-coding system has been recommended with proper validation to the company for solving the problem of wrong issuing of the materials to different sections. This work has been done for a small medium scale manufacturing company of Northern India.

The impact of Quality Maintenance Pillar of TPM on manufacturing performance

The purpose of this paper is to demonstrate the contributions of Quality Maintenance (QM) Pillar of TPM approach in improving the product quality in a food industry manufacturing potato chips. QM Pillar is an important initiative of TPM methodology which aims to give customer delight through defect free manufacturing. The effective TPM implementation enhances production efficiency with an ultimate aim of attaining zero breakdowns, zero losses and zero defects. The focus of QM Pillar is on eliminating non-conformances in a systematic manner and maintaining equipment to produce high quality products. The QM pillar activities in the industry remained successful in reducing the customer complaints and regulatory complaints to zero. Also, considerable reduction in number of major defects occurred and leakage problems reduced from 1.20% to 0.27%. The QM pillar targets are achieved successfully by the industry such as sustaining customer complaints at zero, reduce in-process defects by 83% and reduce cost of quality by 46%.

Reverse logistics network design for spent batteries: a simulation study

End of life (EOL) product management, which encompasses reuse, remanufacturing and materials recycling, requires a structured reverse logistic network in order to collect products efficiently at the end of their life cycle. This work describes modelling and simulation of reverse logistics network design for collection of spent batteries for Sangrur District of North India. To compare different order assignment, a simulation model of forward and reverse logistics networks has been developed. Several simulation experiments have been designed to analyse impact of the system design factors on the operational performance of the reverse logistics system. The simulation results show that the model presented in this paper calculates the battery collection cost, transfer time, transfer cost, and resource utilisation in a predictable manner. Moreover, it provides a tool to understand how the system behaves by carrying out ‘what-if’ assessments and to identify which parameters are most important for more detailed an...