Applied Mechanics and Materials Vols. 229-231

Abstract: Malaysia is a developing nation and the manufacturing sector is the major contributor to the Malaysian economy. In the year 2009, Small and Medium Enterprises (SMEs) contribute to 28,840 establishments which represented 94.2 percent of the total establishments in the manufacturing sector in Malaysia. Welding is a common industrial process in manufacturing sector that has both acute and long term chronic hazards mainly from the inhalable welding fumes. Welding fumes assessment in SMEs welding workplace is essential in order to ensure the minimum level of exposure is maintained as required by the prevailing standards. However, providing concentration or emission information alone is insufficient and meaningless to the workers and company management. There is an urgent need to develop an index which served as a ranking tool in comparing environmental condition at different location and to simplify complex health hazard issues of welding fumes that can be comprehended easily by the workers and company management. Preliminary ideas on the derivation of the sub-index from rating of health effect, mixture hazard, doses and weightage of metal fumes element were outlined in this paper. At the end of this paper, future works regarding aggregation factor and verification of the index were also discussed.

Abstract: The purpose of the paper is to determine the applicability of external setup preparation activities of Single Minute Exchange of Die (SMED) in reducing setup time. Improving the external setup preparation of SMED leads a better and effective working performance. To improve the effectiveness of the external setup in SMED, it is concerned particularly with changing the internal activities into external activities and improving the current external activities. The process failure mode and effect analysis (PFMEA) adopted to analyze the problem faced of external set up process.The verification of the methods is done by an application a plastic injection molding manufacturing process where setup times are critical for time reduction.

Abstract: Nowadays, the research scope of Computer Numerically Controlled (CNC) vendors is to provide an interoperable controller to the industry, which has a capability to deal with more intelligent systems. G-code (ISO6983) as an information processing system has been used over the years, but by the development of systems during the generation of computer in industry the shortcomings of this information processing system becomes visible. STEP-NC as a new standard is being developed to remove barriers of ISO6983 such as lack of manufacturing interoperability between CAD/CAM/CAPP/CNC chains. In this paper, the lack of manufacturing interoperability between systems and solution in each one is reviewed, and then the case study has been developed to indicate power of STEP-NC in removing this barrier between different CNC’s.

Abstract: The sustainability concept today is at the front lines of new technologies in manufacturing, products and work methodology. Be a sustainable manufacturer is critical issue to the future of manufacturing system. Various efforts have been conducted around the world to ensure the sustainability of manufacturing system. This study addresses current trend in sustainable manufacturing by focus on two major elements, which are facility design and production planning. Critical challenges are listed and future trends have been discussed.

Abstract: This paper discusses about unprecedented challenges in consequence of globalization and competitive market conditions which manufacturing industries have to face with. Besides changing environmental regulation and social and regional demand, these challenges, will introduce e-manufacturing concept to deal with the recent needs. Manufacturers become more agile and nimble by development of internet. On one hand, it affects differently on the sections of process industries. On the other hand, it makes more demand for products and more opportunities to sell and market the products. To support this new concept, E-Manufacturing enablers will be introduced and finally, developments for next generation are discussed.

Abstract: This paper presents an integrated approach for denture (dental prosthesis) manufacturing process by integrating information from patient denture requirement, design flow and manufacturing activities. The aim is to produce a removable complete denture with high degree of precision, good quality of denture and rapid fabrication process. The method includes data acquisition, design process and teeth assembly of the denture that reduces the dependency on experienced craftsmen and reduces the time consumption in denture processing chain. The system also aims to reduce patient visiting times and consequently reduces the expenses. The basic system has been developed at the Faculty of Mechanical and Manufacturing Engineering, UTHM with the cooperation of the School of Dental Sciences, USM and Klinik Pergigian Batu Pahat, Johor. By implementing the integrated system, denture can be produced using centralize manufacturing facilities of several dental clinics and provide denture replacement services which can be delivered in 24hrs. Although the basic system has been tested and found very satisfactory result, there are development works and improvements are still needed in order for the system ready for commercialization.

Abstract: In contrast with all advantages of composite materials, susceptibility of these materials to impact damage became a major concern recently. The aim of this research is to investigate the dynamic response of laminated composite cylindrical shell subjected to pure impact numerically. For this purpose, the impact of a steel ball on composite cylinder is modeled in Abaqus software as a point load and the amount of radial deflection and contact force of the contact point on cylinder surface is recorded for whole period of contact motion. To validate the obtained results they were compared with the exactly the same model in published data. According to obtained results, both of radial deflection and contact force have a parabolic variation during the impact motion. The maximum radial deflection occurs when the striker has its maximum penetration and bouncing back motion is just about to start.

Abstract: The high temperature proton exchange membrane fuel cell (HT-PEMFC) is widely paid attention to due to the characteristics of simple water management, high intolerance of CO and high utilization of heat. In order to discover the effects of different operating factors on the performance of HT-PEMFC, several sets of experiments based on pyridine polymer were carried out in the testing system testing VI curves. The experimental results show that the fuel cell temperature affects enormously on the performance of the HT-PEMFC; humidification of reactant on the performance is almost negligible, which contribute to the understanding the working mechanism of HT-PEMFC.

Abstract: This study combined the numerical analysis and experimental measurement to investigate the conjugate conduction and natural convection for a block heat source module in a three-dimensional cabinet filled and surrounded by air. The effects of Rayleigh number Ra, module position C1, ratio of block to air thermal conductivities Kbf, and ratio of board to air thermal conductivities Kpf are examined. Moreover, efforts are carried out to explore the influence of thermal interaction between the air streams inside and outside the cabinet.

Abstract: The formula and calculating method of specific heat ratio in confined explosion with small explosive charge volume ratios under considering chemical reactions of the detonation products was researched. Taking the TNT explosive as an example, a numerical calculating program was written, and the specific heat ratio of the confined explosion either considering the influence of the chemical reactions or not were calculated by the program.