Feature technology and its applications in computer integrated manufacturing

A Thesis submitted for the degree of Doctor of Philosophy of University of LutonComputer aided design and manufacturing (CAD/CAM) has been a focal research area for the manufacturing industry. Genuine CAD/CAM integration is necessary to make products of higher quality with lower cost and shorter lead times. Although CAD and CAM have been extensively used in industry, effective CAD/CAM integration has not been implemented. The major obstacles of CAD/CAM integration are the representation of design and process knowledge and the adaptive ability of computer aided process planning (CAPP). This research is aimed to develop a feature-based CAD/CAM integration methodology. Artificial intelligent techniques such as neural networks, heuristic algorithms, genetic algorithms and fuzzy logics are used to tackle problems. The activities considered include: 1) Component design based on a number of standard feature classes with validity check. A feature classification for machining application is defined adopting ISO 10303-STEP AP224 from a multi-viewpoint of design and manufacture. 2) Search of interacting features and identification of features relationships. A heuristic algorithm has been proposed in order to resolve interacting features. The algorithm analyses the interacting entity between each feature pair, making the process simpler and more efficient. 3) Recognition of new features formed by interacting features. A novel neural network-based technique for feature recognition has been designed, which solves the problems of ambiguity and overlaps. 4) Production of a feature based model for the component. 5) Generation of a suitable process plan covering selection of machining operations, grouping of machining operations and process sequencing. A hybrid feature-based CAPP has been developed using neural network, genetic algorithm and fuzzy evaluating techniques

A framework for green manufacturing practicies in small and medium enterprises in Malaysia

Green Manufacturing Practices (GrMP) is a term used to describe manufacturing practices that do not harm the environment during any part of the manufacturing process. It emphasizes the use of processes that do not pollute the environment or harm consumers, employees, or other members of the community. Small and medium enterprises (SMEs) are moving toward sustainable alternatives through GrMP method. It stresses on critical factors such as organisational style, eco-knowledge, business environment, society influences, supply chain management and technology network. Large size industries are more compelled to do so compared to SMEs due to the fact that they are more influential with better organizational management and good financial stability compared to SMEs. However, SMEs are trying to adapt GrMP as a mandatory process, but lack of proper framework which guide them for implementation. Therefore, this study developes the framework of GrMP for local SMEs. The study involves enablers and barriers in implementing GrMP from previous literatures. This work formulate a framework based on relationship between criticals factors with enablers and barriers. 59 of respondents from local industries in Malaysia were selected as respondents based on six of critical factors divided into two parts which are enablers and barriers. The questionnaire are designed based on this. Survey were evaluated by using Statistical Package for the Social Sciences (SPSS) version 23, in terms of correlation, reliability, central tendency and variability testing. The finding on this study in the term of framework will help SMEs to implementing GrMP. Framework formulate relates the critical factors from previous literature and enablers and barriers from survey based on perception of industries expert. GrMP for SMEs are the first step of environmental awareness and ecological responsibilties

Pembangunan Modul Pengajaran Kendiri (MPK) keusahawanan dalam topik isu keusahawanan bagi pelajar diploma di politeknik

Terdapat pelbagai kaedah pembelajaran yang telah diperkenalkan termasuklah kaedah pembelajaran yang menggunakan pendekatan pembelajaran bermodul secara kendiri. Kajian ini adalah bertujuan untuk mengkaji kesesuaian Modul Pengajaran Kendiri Keusahawanan dalam topik Isu Keusahawanan yang telah dihasilkan bagi pelajar yang mengikuti pengajian Diploma di Jabatan Perdagangan Politeknik. Antara aspek yang dikaji ialah untuk menilai sama ada rekabentuk modul yang dihasilkan dapat memenuhi ciri-ciri modul yang baik, MPK yang dihasilkan dapat membantu mencapai objektif pembelajaran, MPK ini bersifat mesra pengguna dan MPK yang dihasilkan membantu pensyarah menyampaikan pengajarannya dengan lebih berkesan. Kajian ini dilakukan ke atas 110 orang pelajar semester en am yang mengikuti pengajian diploma dan 4 orang pensyarah yang mengajar subjek Keusahawanan di Jabatan Perdagangan Politeknik Sultan Salahuddin Abdul Aziz Shah, Selangor. Kaedah analisa data yang digunakan dalam kajian ini ialah skor min dan peratus. Hasil daripada kajian ini menunjukkan bahawa rekabentuk modul yang dihasilkan memenuhi ciri-ciri modul yang baik, MPK ini membantu untuk mencapai objektif pembelajaran, MPK ini bersifat mesra pengguna dan MPK yang dihasilkan dapat membantu pensyarah menyampaikan pengajarannya dengan lebih berkesan. Ini bermakna secara keseluruhannya, hasil kajian menunjukkan bahawa modul yang dihasilkan oleh pengkaji adalah sesuai digunakan oleh pelajar-pelajar semester enam yang mengikuti pengajian diploma di Jabatan Perdagangan peringkat politeknik. Seterusnya, beberapa pandangan telah dikemukakan bagi meningkatkan rnutu dan kualiti MPK yang dihasilkan. Semoga kajian ini dapat memberi manfaat kepada mereka yang terlibat dalam bidang pendidikan

Topological model for machining of parts with complex shapes

Complex shapes are widely used to design products in several industries such as aeronautics, automotive and domestic appliances. Several variations of their curvatures and orientations generate difficulties during their manufacturing or the machining of dies used in moulding, injection and forging. Analysis of several parts highlights two levels of difficulties between three types of shapes: prismatic parts with simple geometrical shapes, aeronautic structure parts composed of several shallow pockets and forging dies composed of several deep cavities which often contain protrusions. This paper mainly concerns High Speed Machining (HSM) of these dies which represent the highest complexity level because of the shapes' geometry and their topology. Five axes HSM is generally required for such complex shaped parts but 3 axes machining can be sufficient for dies. Evolutions in HSM CAM software and machine tools lead to an important increase in time for machining preparation. Analysis stages of the CAD model particularly induce this time increase which is required for a wise choice of cutting tools and machining strategies. Assistance modules for prismatic parts machining features identification in CAD models are widely implemented in CAM software. In spite of the last CAM evolutions, these kinds of CAM modules are undeveloped for aeronautical structure parts and forging dies. Development of new CAM modules for the extraction of relevant machining areas as well as the definition of the topological relations between these areas must make it possible for the machining assistant to reduce the machining preparation time. In this paper, a model developed for the description of complex shape parts topology is presented. It is based on machining areas extracted for the construction of geometrical features starting from CAD models of the parts. As topology is described in order to assist machining assistant during machining process generation, the difficulties associated with tasks he carried out are analyzed at first. The topological model presented after is based on the basic geometrical features extracted. Topological relations which represent the framework of the model are defined between the basic geometrical features which are gathered afterwards in macro-features. Approach used for the identification of these macro-features is also presented in this paper. Detailed application on the construction of the topological model of forging dies is presented in the last part of the paper

PCPro a Novel Technology for Rapid Prototyping and Rapid Manufacturing

PCPro stands for Precise Cast Prototyping, which is a combination of casting technologies and milling. This method was developed at Fraunhofer IWS in Dresden, Germany. It is patented in Germany [1] and is applied in the USA under US 10/794,936. The main goal for this development was to shorten the process chain for making plastic prototypes accompanied by higher quality. The casting technology was integrated in a machining center in order to enable a high degree of automation and to avoid an external casting system. This means that Rapid Manufacturing can be easily implemented using such an automated combination of casting and machining. This article describes the PCPro method by means of the fabrication of sample parts. The advantages and the limitations in comparison to common Rapid Prototyping and Rapid Manufacturing process chains will be discussed. In addition, the manufacturing of a prototype machine is presented.Mechanical Engineerin

Goods and services tax (GST) on construction capital cost and housing property price

Good and Service Tax (GST) an indirect broad-based conswnpti.on tax. Following with the implementation of GST in Malaysia on 1st April 2015, it is suspected that the construction capital cost and housing property price will increase accordingly. This study is aim to review the GST effect associated on construction capital cost and it influences towards housing developer and housing property price. Additionally, this study highlights what was the developer point of view on the GST given to them and also the housing price further proposes initiatives to the housing developers. Argument of GST effect is useful for the public administrators so that to re-consider the rate of GST and also beneficial to the construction parties to account with the GST implementation. As conclusion, this study review that GST do give an impact towards the construction capital cost, housing developer and housing property price in terms of knock-on effect

Effect of PAO-based γ-Fe2O3 and surfactant concentration on viscosity characteristic

This is a preliminary study on the viscosity characteristics of polyalphaolefin (PAO)- based γ-Fe2O3 under zero magnetic fields. By varying the concentration of magnetic nanoparticles (MNPs), PAO-based γ-Fe2O3 with different concentrations were synthesized by co-precipitation method. The effect of this factor on the viscosity characteristic of γ-Fe2O3 (< 30 nm) was investigated on the basic of a series of rheological measurement. The use of oleic acid (OA) as a coating agent and surfactant was also investigated by varying its concentration. The results show the concentration of MNPs and the amount of OA has obvious effect on viscosity characteristics of PAO-based γ-Fe2O3. In the case of comparison between the concentrations of MNPs, higher concentration of MNPs increased the viscosity of the PAO-based γ-Fe2O3 and exhibit nearly Newtonian behavior. The large amount of OA also exhibits the increment on viscosity characteristic of MNPs. The experimental data were compared with the Bingham and Casson model and the results revealed that the rheology of the polyalphaolefin (PAO)-based γ-Fe2O3 fitted the Casson model better

Goods and services tax (GST) on construction capital cost and housing property price

Good and Service Tax (GST) an indirect broad-based conswnpti.on tax. Following with the implementation of GST in Malaysia on 1st April 2015, it is suspected that the construction capital cost and housing property price will increase accordingly. This study is aim to review the GST effect associated on construction capital cost and it influences towards housing developer and housing property price. Additionally, this study highlights what was the developer point of view on the GST given to them and also the housing price further proposes initiatives to the housing developers. Argument of GST effect is useful for the public administrators so that to re-consider the rate of GST and also beneficial to the construction parties to account with the GST implementation. As conclusion, this study review that GST do give an impact towards the construction capital cost, housing developer and housing property price in terms of knock-on effect