Majid Hashemipour

A modular virtual reality system for engineering laboratory education

The globalization trend has affected the tertiary education sector, resulting in an increased flow of both students and academics across borders. Economic pressures on universities and the emergence of new technologies have spurred the creation of new systems in engineering education. The recent advances in computer graphics have exposed great potential in education at all levels. The Virtual Reality (VR) is a promising technology which aims to assist the students in the visualization of concepts and to provide immediate graphical feedback during the learning process. This article presents a modular interactive teaching package, called Virtual Learning System (VLS), which can be used by people with little prior computer experience. VLS provides a comprehensive and conductive yet dynamic and interactive environment that can be incorporated into various courses in the field of Mechanical and Manufacturing Engineering. The evaluation of the learning process with the developed system has been done through laboratory reports, lab quizzes and questionnaires implemented with a tutorial monitoring application.

Virtual reality in requirement analysis for CIM system development suitable for SMEs

This paper presents a methodology, based on Virtual Reality (VR), for representing a manufacturing system in order to help with the requirement analysis (RA) in CIM system development, suitable for SMEs. The methodology can reduce the costs and the time involved at this stage by producing precise and accurate plans, specification requirements, and a design for CIM information systems. These are essentials for small and medium scale manufacturing enterprises. Virtual Reality is computer-based and has better visualization effects for representing manufacturing systems than any other graphical user interface, and this helps users to collect information and decision needs quickly and correctly. A VR-RA tool is designed and developed as a software system to realize the features outlined in each phase of the methodology. A set of rules and a knowledge base is appended to the methodology to remove any inconsistency that could arise between the material and the information flows during the requirement analysis. A novel environment for matching the physical and the information model domains is suggested to delineate the requirements.

Virtual-reality-based information requirements analysis tool for CIM system implementation: a case study in die-casting industry

A virtual-reality-based information requirement analysis tool (VR–RA tool) has been developed for an existing methodology, in order to capture and represent the enterprise information requirements of computer integrated manufacturing (CIM). The present paper describes the operational aspects of the existing methodology in VR–RA and introduces the developed VR–RA tool, which can be used by system analysts for determination of information requirements. A virtual manufacturing environment for matching the physical and the information model domains is utilized to delineate the information system requirements of CIM implementation. A set of rules and a knowledge base is appended to the virtual environment to remove any inconsistency that could arise between the material and the information flows during the requirement analysis. An experimental case study has been carried out in a firm in the die-casting industry in order to demonstrate the features and the potential industrial application of the VR–RA tool outlined in the current paper.

High-Speed Incremental Forming Process: A Trade-Off Between Formability and Time Efficiency

Making use of “optimal experimental design,” the paper attempts to investigate individual and interactive effects of predictor parameters, namely tool size, pitch size, feed rate, spindle rotational speed, and blank thickness, on sheet formability in single point incremental forming (SPIF) process. For the sake of precision, a novel sensor system was developed and employed to detect crack as it initiates on SPIF test specimens. A novel benchmark for formability in SPIF was established by addressing normal strain along sheet thickness, maximum attainable forming angle, and the rate of variation in forming angle. The process was finally optimized in terms of maximum achievable formability and minimum processing time. Accordingly, high-speed forming (with forming speed of at least 5000 mm/min) was realized to be perfectly viable, whereas the sheet formability remains quite satisfactory (over 90% of the maximum value). The key role of high spindle speed (up to 3000 rpm) was also highlighted in this regard.

Numerical optimization of hole making in GFRP composite using abrasive water jet machining process

Machining of composite materials for the production of bolt holes is essential in the assembly of the structural frames in many industrial applications of glass fiber-reinforced plastic (GFRP). Abrasive water jet cutting technology has been used in industry for such purposes. This technology has procured many overlapping applications and as the life of the joint in the assembled structure can be critically affected by the quality of the holes, so it is important for the industry to understand the application of the abrasive water jet cutting process on GFRP composite materials. The aim of the present work is to assess the influence of abrasive water jet machining parameters on the hole making process of woven-laminated GFRP material and to find the optimum values of the process parameters. Statistical approach was used to understand the effects of the predicted variables on the response variables. Analysis of variance was performed to isolate the effects of the parameters affecting the hole making in abrasive water jet cutting. The results show that the optimum values of cutting feed, fiber density, water jet pressure, standoff distance, and abrasive flow rate upon the response variables are 0.3 m/min, 0.82 g/cm3, 150 MPa, 2 mm, and 100 g/min, respectively.

A framework for structural modelling of an RFID-enabled intelligent distributed manufacturing control system

A modern manufacturing facility typically contains several distributed control systems, such as machining stations, assembly stations, and material handling and storage systems. Integrating Radio Frequency Identification (RFID) technology into these control systems provides a basis for monitoring and configuring their components in real-time. With the right structural modelling, it is then possible to evaluate designs and translate them into new operational applications almost immediately. This paper proposes an architecture for the structural modelling of an intelligent distributed control system for a manufacturing facility, by utilising RFID technology. Emphasis is placed on a requirements analysis of the manufacturing system, the design of RFID-enabled intelligent distributed control systems using Unified Modelling Language (UML) diagrams, and the use of efficient algorithms and tools for the implementation of these systems.

Forming Parameters and Forming Defects in Incremental Forming Process: Part B

Single point incremental forming (SPIF), at present, is suffering from defects. With an aim to enhance understanding on their development to control them methodically, FE analyses by varying four parameters are performed in the present study. It is found that, while deforming sheet, stresses develop in the bottom of part. The SPIF defects are in fact outgrowth of these stresses. More precisely, the ratio of vertical- to horizontal-stress is a principal factor that controls (or causes) defects. The development of wall defect depends on the stress ratio in the tool/blank contact (zone A), while that of pillow defect depends on the stress ratio both in the tool/blank contact (zone A) as well as in the center of parts bottom (zone B). Moreover, the magnitude and nature (tension or compression) of the stress ratio, subject to the type of parameter, varies as a parameter is varied. These variations in the stress state in turn affect the defects growth (or size). It is concluded that the stress ratio both in zone A and in zone B needs to be simultaneously controlled so as to overcome the SPIF defects.

Toward a framework for intra-enterprise competency modeling

The purpose of this paper is to propose a framework for intra-enterprise competency modeling. A case study to illustrate the adopted concepts and developed framework is discussed. Based on the proposed framework, emphasis is placed on investigating the capability models in different departments of the enterprise with the goal of enhancing enterprise decision making process.

A framework for modelling enterprise competencies: from theory to practice in enterprise architecture

Enterprise competency refers to knowledge that describes the skills and abilities possessed by a particular enterprise. This paper proposes a new framework for intra-enterprise competency modelling. First, formal definitions of enterprise competency and related aspects (i.e. resource, activity, and knowledge) are presented. Second, conceptual subcategories (i.e. capability, cross-functional co-ordination, and cross-functional integration) are discussed for the purposes of capability and competency modelling. The framework is illustrated by developing a competency knowledge base for a bicycle plant with two sectors. The competency knowledge base provides information important to decision-making, and can act as an indicator for an enterprise’s willingness to engage in robust collaboration.

Toward a Modeling Framework for Organizational Competency

Competency modeling framework serves as a; (a) very important basis for the explanation of a generic competency modeling approach, (b) base element in the consolidation of existing knowledge in this area, (c) tool for model developers on selecting appropriate competency models, and (d) basis for competency modeling. This research uses literature review approach to propose a modeling framework for organizational competency. The proposed modeling framework has been developed based on the most relevant well known competency models. The research suggests that organizational competency can be categorized into three groups; individual competency, enterprise competency and collaboration-oriented competency. For modeling each of these groups, it is essential that the modeling process have to be aligned with model developer purpose (Modeling perspective), thus the model developing process will be based on the same segmentation model. Furthermore, competencies have to be model at different levels of abstraction (modeling intent).