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| Articles
by
S. Abdullah |
Total Records (
4 ) for
S. Abdullah |
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S. Abdullah
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D.A. Wahab
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This study discusses the concurrent application of design methodologies for the generation of engineering conceptual design in product design projects. The projects, or so called the capstone engineering design project, were carried out by groups of final year students in the Department of Mechanical and Materials Engineering (DMME), Universiti Kebangsaan Malaysia (UKM). To align with the Problem-Based Learning (PBL), which is a criterion in recent engineering education, the level of students` understanding in performing the engineering design project is highly required. Accordingly, this paper focuses on the use of the concurrent engineering approach in the concept generation phase with the application of the Pugh and Cross models. Methods to generate design ideas and design concepts such as brainstorming and the morphological chart were applied during the design process. Each of these methods has its own strength and it is necessary to apply them together to produce design ideas, leading to the development of more meaningful conceptual designs. To have a further outline of this situation, a case study on conceptual design generation performed by a group of undergraduate students from the DMME UKM is presented. Findings from the case study showed that better conceptual designs were generated, indicating improvements in the students` capabilities and creativity in the PBL engineering design projects. |
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S. Abdullah
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The actual road load time histories which were experimentally measured on a automotive component contains variable amplitude patterns, having a mixture of low and high amplitudes cycles. In terms of fatigue damage characterization, these low amplitude cycles have little or no effects to the failure of metallic components. Due to the importance of high amplitude events in the fatigue time histories, it shows an interest to explore a fatigue data compression technique (or also known as fatigue history editing) using a signal processing approach. Several computational algorithm of the fatigue data editing have been previously developed. Instead of these, the author used the time-frequency (or wavelet) approach in developing an alternative solution and it is called Wavelet Bump Extraction (WBE). For the scope of this study, the discussion will focus on the applicability of WBE using variable loadings. |
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S. Abdullah
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M.Z. Nuawi
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This study describes the use of the S-Transform to identify fatigue features in variable amplitude loadings. In normal situation, experimental fatigue loadings exhibit variable amplitude and nonstationary loading pattern, for which the traditional frequency domain analysis cannot provide accurate results. However, the time-localisation transform provides a promising solution. Since the S-transform if the simplification of the advanced time-frequency localization method, i.e., the wavelet transform, it is a good idea to study this transform in order to identify these fatigue features. The results obtained from this study showed that the high amplitude events were detected in the variable amplitude loading based on the difference pattern of the time-frequency localisation. These results were also compared to the plot of moving-damage using the Morrow’s strain-life fatigue damage model. Based on the promising outcomes, finally, it is proposed that further study of the S-transform should be carried out in broader scope of fatigue life assessment.
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S. Abdullah
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M.D. Ibrahim
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A. Zaharim
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I. Ahmad
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This study describes the analysis of fatigue road loading using the Moving Average approaches. Thus, techniques for preserving data associated to the underlying probabilistic properties were introduced. Fatigue damage cumulating is a random variable in essence. The randomness comes from the loading process and fatigue resistance of material. Seldom have models dealing with fatigue damage cumulating considered the co-influence of the two aspects of randomness at the same time. This article has established a probabilistic distribution model of moving average fatigue damage. In the model, the moving average trend can be estimated by smoothing the data to reduce the random variation and randomness at fatigue resistance of material is described by introducing a random variable of a variable amplitude loading sampled at 200Hz. This model can calculate the fatigue damage cumulating distribution after moving.
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