Applied Mechanics and Materials Vols. 465-466

Abstract: This work presents a study of energy absorption performances of pultruded composite tubes under quasi-static compressive loadings. The as-received tubes were chamfered at 35, 45 and 55⁰. The purpose of chamfered tube edge is to initiate the crushing process and to make sure the tubes were progressively collapsed under quasi-static compressive loadings. According to the present results, for 3 mm tube thickness, varying chamfering angles are not significantly affected the force-displacement curves. Except for the case of 55⁰ showed higher peak force compared with other angles. However, if the thickness is increased to 5 mm, the effect on the curves of force versus displacement is tremendous where higher chamfering angles produced higher energy absorption performances.

Abstract: This research explored ISO 14649 together with ISO 6983 and utilize STEP-NC in overcoming the problems of G & M code and at the same time take advantage of the current advances in computing and controllers. A new STEP-NC Code Generator called Milling STEP Coder, which focuses on the milling process that are able to generate STEP-NC codes based on ISO 14649 Part 11 was developed. This system also has the capabilities to visualize the STEP-NC codes generated in a parent to child relationship tree-view structure, as well as give an image visualization of how the end machining will appears. The developed Milling STEP Coder uses Software Prototyping Model as its software development methodology, instead of the normal waterfall model, as prototype is a valuable mechanism for gaining better understanding of the system requirements. A small-scale mock up of the system was developed following an iterative modification process. The advantages of the proposed Milling STEP Coder program was verified and evaluated. The Milling STEP Coder can generates STEP-NC codes through a STEP-NC compliant interface and will give industries and academician more in-depth understanding and confidence to make the switch from G & M code to STEP-NC.

Abstract: Different designs of manufacturing systems are adopted in industry today. A good manufacturing design should be flexible to compensate for uncertainties such as demand fluctuations and machine breakdowns. A new conceptual manufacturing system called Multi-Channel Manufacturing (MCM) is expected to provide flexibility and efficiency under uncertainties. This paper proposes the first approach to address the usefulness of MCM. This research tries to identify the key characteristics of MCM and the manufacturing environments for which MCM should perform well. Through simulation models, different manufacturing scenarios are analyzed and a suitable manufacturing system design for each scenario is identified. The simulation results illustrate that with limited material handling capacity and opportunities for setup time reduction, MCM can outperform other manufacturing formations.

Abstract: The objectives of the project are to simulate linear Mamdami type fuzzy temperature controller and non-linear Takegi-Sugeno type fuzzy temperature controllers using MATLAB and Simulink, and to compare the performance between the two controllers. A case study has been created to test the controllers involved a water boiler, where the system is modeled using Joules Law and Law of Thermodynamics. A Proportional-Integral-Derivative (PID) controller was tuned and the PID parameters were then used to obtain the gain of the fuzzy controllers. Simulation results confirmed that non-linear fuzzy controller has smaller overshoot and faster settling time compared to the linear fuzzy controller and PID controller, although an extra derivative gain may be needed for the non-linear fuzzy controller if the integral term is huge enough to affect the stability of the system.

Abstract: In order for humans and robots to interact in an effective and instinctive manner, robots must obtain information about the human emotional state in response to the robots actions. This is important as the presence of robot in manufacturing industry is very wide and robot plays a big role in the emerging of automation manufacturing technology. Consequently, we believed that it is necessary to investigate how human feel about this situation and if robot can understand those human emotions, collaboration with human can be much better. In order to investigate the human emotions, we applied a kansei survey method based on a kansei engineering technology. We request a number of participants to take part in our experiment where they will be in the same environment of where a robot is working on some tasks. The participants will answer those questions in the survey based on what they feel about working together with moving robot. The overall goal is, in fact, to predict in which area in the vicinity of the robot that the human is heading to, especially in term of humans feeling, so that by understanding how human feels of working together with robots, perhaps we can create a better working environment. This paper describes the results of our findings about how human feel when collaborating with robot (s).

Abstract: The parameters and its influence on the winding design of an inductor was investigated, using Taguchis method, with the aim of selecting an optimum set of parameters. An experimental design was use to determine the optimal combination of parameters corresponding to various contour designs that would result in minimum fall out ratio and minimum machine error processing. An orthogonal array factorial run was employed to determine an optimal set of parameters and to determine the influence of parameters such as wind start post, finishing angle, winding width and winding pitch on the performance. Based on the results from the analysis, it is concluded that the winding width is the most significant parameter related to fall out ratio. Additionally, the parameter winding width will define the optimum contour design in terms of geometry of design shape.

Abstract: In this study, the tube sinking process for manufacturing the micro Ti-0.2Pd tube (2.4 mm external diameter, 0.4 mm thickness) was simulated by finite element analysis. The external diameter of the initial tube was 5.0 mm. In order to simulate the tube sinking process, the flow stress equation was deducted from the result of the tensile test and friction coefficient was indirectly obtained through the parameter studies. The simulation results showed the simulation error according to the change of diameter predicted to be less than 2%. The defect of the internal surface by stress was found through the experiment result.

Abstract: Dynamic analysis is very important in developing machine structure to sustain the required accuracy, reliability and productivity. The objective of this study is to conduct a dynamic and modal analyses of micro-milling machine. The machine designs were predicted by comparing the Finite Element Analysis (FEA) using ANSYS software and experimental hammer testing. Two micro-milling machine designs have been proposed. Natural frequency and mode shape was analyzed in modal analysis which show the result that first mode recorded frequency of 92.086 Hz for design A and 154.78 Hz for design B. Natural frequency of design B was higher than design A. From the comparision, it can be concluded that Design B was selected as a best design.

Abstract: This work presents the tube forming characteristics of a trailing arm which the whole forming processes are arranged through pre-bending twice and hydro-forming once. This work utilizes the finite element method to simulate the hydro-forming process of the trailing arm by changing the process parameters, such as velocity of left and right punches and internal hydraulic pressure, etc. The effects of process parameters on the distribution states of the tube wall-thickness, distribution of equivalent stresses and strains, and formability of the forming arm are thus investigated. Taguchi method, orthogonal array and factor response are then applied together to determine the optimal process parameter combinations corresponding to two single-quality objects, minimum tube wall-thickness and maximum equivalent stress, with nominal-the-best and smaller-the-better, respectively. It shows that the velocity of the right punch for the billet material axial feeding supplement should be larger than that of the left punch preventing the uneven bursting of the tube-wall on right-end. The analysis of variance also shows that left punch velocity is a major contribution parameter for tube wall-thickness while that primarily affects the equivalent stress is the internal pressure.

Abstract: Current trend for manufacturers associated to MIM industry try to enhance the feedstock in term of its characteristics, since it is the most crucial part of the MIM process. This paper covered the characterization and rheological studies on a ready-made feedstock of stainless steel 316L which is vital to determine the availability and suit the needs of many advanced applications. There are three different experiments involved which are Scanning Electron Microscope (SEM), Differential Scanning Calorimeter (DSC), Thermogravimetric (TGA) and Capillary Rheometer. Observation through SEM gives an insight of the bonding microstructure matrices of the feedstock and also determines the homogeneity of the feedstock. DSC testing defines the melting temperature of the 3 binders used which are 62.07°C for surfactant, 178.72°C for filler and 236.61°C for backbone binder. From TGA result, it showed that the total weight loss of feedstock was 39%. Throughout the capillary rheometer testing, the feedstocks viscosity was decreasing as the shear rate increasing. The feedstock exhibits pseudoplastic behaviour since its flow behaviour index was less than 1. It is founded that at the temperature of 190°C, the feedstock exhibits the best characteristics for injection.