Finite Element Analysis of Steel Quenching Process

The finite element method (FEM) is employed to investigate the residual stress state and the variation of internal stresses in the St5O cylinder bar quenched from 600 to O°C. Thermal analysis is first performed to obtain the cooling curves for the core and surface of the bar, this is followed by a full structural analysis. The results obtained from the computer simulation are compared with those experimentally determined values that are available in the literature and there appears to be a good measure of agreement. The study found that at the initial stages of the quenching process, the residual stresses were tensile at the surface and compressive in the core, however, towards the end of the quenching process, the tensile residual stresses switched to the core and compressive residual stresses at the surface

Fuzzy Rules Optimization in Fuzzy Expert System for Machinability Data Selection: Genetic Algorithms Approach

Machinability data selection is complex and cannot be easily formulated by any mathematical model to meet design specification. Fuzzy logic is a good approach to solve such problems. Fuzzy rules optimization is always a problems for a complex fuzzy rules from more than 10 thousand combinations. (Wong et aL 1997) developed fuzzy models for machinability data selection. There are more than 2 x 1029 possible sets of rules for each model. Situation would be more complicated if further increase the number of inputs and/or outputs. The fuzzy rules were selected by trial and error and intuition in reference (Wong et aL 1997). Genetic optimization is suggested in this paper to further optimizing the fuzzy rules optimization with genetic algorithms has been developed. Weighted centroid method is used for output defuzzi fication to save processing time. Comparisons between the results of the new models and the previously published literatures are made

Finite element analysis of sheet metal forming process

Minimization of response times and costs and maximization of the efficiency and quality in producing a product are imperative for survival in the competitive manufacturing industry. Sheet metal forming is a widely used and costly manufacturing process, to which these considerations apply. Aluminum sheet becomes favorable compare to steel regards to some improvement at aerodynamic designs, increased engine efficiency and fuel economy. Wide range of aluminum automotive product included doors, fenders, bumpers face bars, seat frames and roof panels have been produced. This paper was carried out to study the finite element (elastic-plastic) analysis of sheet metal forming process using the finite element software. LUSAS simulation was carried out to gain accurate and critical understanding of sheet forming process. Axisymmetry element mesh and plain strain element mesh were use incorporated with slideline features to model and study the sheet metal forming process. Simulation of elasticplastic behavior of aluminum sheet was carried out under non-linear condition to investigate sheet metal forming process

Experimental study of corrugated metal-composite tubes under axial loading

In this study, crushing behavior of corrugated metal-composite tube was examined experimentally under axial loading condition. Six types of specimens, classified into two groups of metal and metal-composite, were tested under quasi static axial loading. The failure mechanism and failure history of the specimens were presented and discussed. The experimental result showed that corrugated metal composite tubes demonstrate perfect energy absorption characteristics in terms of uniformity of load-displacement diagram, reduction of initial peak load and controlling failure mechanism. Moreover, it was also found that adding filament wound layer of composite on the surface of metallic corrugated tube compensated weakness of corrugated metal tubes, which is low energy absorption capacity. Metal-composite corrugated showed high energy absorption capacity as well as preferable crushing characteristic under the axial loading

The Effect of Number of Corrugation on Crashworthiness of Aluminum Corrugated Tube under Lateral Loading

Thin-walled tubes have been developed and are growing in use as new energy absorber structures. The objective of this study is to investigate the energy absorption and crushing characteristics of corrugated tubes with different number of corrugation in a specific length exposed to lateral loading. At the first step, experimental tests were carried out on a corrugated tube with three con\u27ugations (two inner and one outer) and a tube without corrugation. After that, a finite element model was developed by means of ABAQUS software in order to study the effect of corrugation number on crushing properties of thin-walled tubes. The results show that tubes with corrugations have a higher mean crushing force which is directly proportional to the number of corrugations. Moreover, the plateau region in load-displacement curve decreases by increasing the number of corrugations and therefore the tube reaches its densification point earlier. Plastic strain variation pattern along the tubes were investigated as well

A new pedagogic modules for training graduate student in research methodology

Research Methodology is a required course common to most graduate programs globally. The applied research methodology course at the College of Engineering, Qatar University is a compulsory course for all graduate students. In this course, various aspects of the foundation, types and methods of research are covered in the curriculum, along with experimental programme planning, research article writing, data processing and depiction, and the increasingly important (and often contentious) subject of bibliometrics. To fully engage the students with the key course element of the reading and critical assessment of published research papers, active learning is introduced. From the first week, students are actively engaged in the course, with the course mentor establishing the motivation for the course and the palpable benefits offered by it in furthering the research and, on a more practical level, the production of research articles. Active debate during presentations is encouraged, creating a climate conducive to critical thinking which underpins research per se. A conference is organized as part of the course to familiarize the students with the processes and etiquette of conference paper submission and presentations. This includes call for papers, submission of abstracts through the online system, communication with conference organizers, conference registration, transferring copyright, and full paper submission according to standard paper format. Each author of an accepted paper is given the opportunity to present their work orally in front of a panel of 4 faculty members and the conference participants. Time management and communication skills form a critical part of the assessment criteria. Students are also expected to develop a complete research proposal, again according to strict criteria as befit those instigated by the various funding agencies. From the course assessment and student course outcomes surveys, it has been found that the interest, engagement and learning curve for students has increased with these novel aspects. In summary, the approach has been interesting and led to further enhancement of the student learning process through the use of different learning styles with varied and innovative teaching techniques.qscienc

Disaster management in industrial areas: perspectives, challenges and future research

Purpose: In most countries, development, growth, and sustenance of industrial facilities are given utmost importance due to the influence in the socio-economic development of the country. Therefore, special economic zones, or industrial areas or industrial cities are developed in order to provide the required services for the sustained operation of such facilities. Such facilities not only provide a prolonged economic support to the country but it also helps in the societal aspects as well by providing livelihood to thousands of people. Therefore, any disaster in any of the facilities in the industrial area will have a significant impact on the population, facilities, the economy, and threatens the sustainability of the operations. This paper provides review of such literature that focus on theory and practice of disaster management in industrial cities. Design/methodology/approach: In the paper, content analysis method is used in order to elicit the insights of the literature available. The methodology uses search methods, literature segregation and developing the current knowledge on different phases of industrial disaster management. Findings: It is found that the research is done in all phases of disaster management, namely, preventive phase, reactive phase and corrective phase. The research in each of these areas are focused on four main aspects, which are facilities, resources, support systems and modeling. Nevertheless, the research in the industrial cities is insignificant. Moreover, the modeling part does not explicitly consider the nature of industrial cities, where many of the chemical and chemical processing can be highly flammable thus creating a very large disaster impact. Some research is focused at an individual plant and scaled up to the industrial cities. The modeling part is weak in terms of comprehensively analyzing and assisting disaster management in the industrial cities. Originality/value: The comprehensive review using content analysis on disaster management is presented here. The review helps the researchers to understand the gap in the literature in order to extend further research for disaster management in large scale industrial cities.Peer Reviewe

Fast upsetting of circular cylinders of aluminium metal matrix composites: experimental results and numerical analysis

Cylindrical specimens of Al/Cu and Al/Li metal matrix composite (MMC) were subjected to dynamic compression at room temperature using an experimental drop hammer. Force-time and displacement-time traces were recorded. The experimental results are compared with theoretical results obtained using finite-difference analysis proposed in a previous paper by the authors [1]. The computational results obtained for the force-time histories agree reasonably with the experimental observation. Effect of strain rate and thermal softening on the mechanical behaviour of Al/Cu MMC and Al/Li MMC were examined

Manufacturing process planning optimisation in reconfigurable multiple parts flow lines

Purpose: This paper explores the capabilities of genetic algorithms in handling optimization of the critical issues mentioned above for the purpose of manufacturing process planning in reconfigurable manufacturing activities. Two modified genetic algorithms are devised and employed to provide the best approximate process planning solution. Modifications included adapting genetic operators to the problem specific knowledge and implementing application specific heuristics to enhance the search efficiency. Design/methodology/approach: The genetic algorithm methodology implements a genetic algorithm that is augmented by application specific heuristics in order to guide the search for an optimal solution. The case study is based on the manufacturing system. Raw materials enter the system through an input stage and exit the system through an output stage. The system is composed of sixteen (16) processing modules that are arranged in four processing stages. Findings: The results indicate that the two genetic algorithms are able to converge to optimal solutions in reasonable time. A computational study shows that improved solutions can be obtained by implementing a genetic algorithm with an extended diversity control mechanism. Research limitations/implications: This paper has examined the issues of MPP optimization in a reconfigurable manufacturing framework with the help of a reconfigurable multiparts manufacturing flow line. Originality/value: The results of the case illustration have demonstrated the practical use of diversity control implemented in the MGATO technique. In comparison to MGAWTO, the implemented MGATO improves the population diversity through a customized threshold operator. It was clear that the MGATO can obtain better solution quality by foiling the tendency towards premature convergence

Design and Simulation of Plastic Injection Moulding Process

This paper presents the design of plastic injection mould for producing a plastic product. The plastic part was designed into two different types of product, but in the same usage function. One part is using clip function and another part is using tick function. In the computer-aided design (CAD), two plastic parts were drawn in 3 dimension (3D) view by using Pro-Engineer (Pro-E) parametric software. In the computer-aided manufacturing (CAM), Pro-Manufacturing from Pro-E parametric software was used to develop the machining program. For mould design, the product was designed into two changeable inserts to produce two different types of plastic product in one mould base. Before proceeding to injection machine and mould design, this part was analysed and simulated by using Mold Flow or Part Advisor software. From the analysis and simulation we can define the most suitable injection location, material temperature and pressure for injection. The predicted weld lines and air trap were also found and analysed