Key Engineering Materials Vol. 572

Abstract: Edge detection is one of the most important steps in image processing and pattern recognition, it is also a critical technology of hand bone identification. Canny edge detection algorithm is simple, easy to implement and fast execution advantage, therefore, it still maintain a certain degree of competitiveness in the practical application. Firstly, the principles and the existing problems of Canny algorithm are studied in this paper, against threshold problem, improved method of an adaptive threshold is proposed, using Otsu method selected threshold, the split results would be better. Finally, the experimental results show that the proposed method can effectively extract the edge of the images.

Abstract: In order to obtain characteristic parameters of the debris from accident pictures for traffic accident reconstruction, MATLAB image processing technology was applied to deal with accident pictures such as grayscale transformation, binarization, noise reduction and segmentation. According to the proportional relationship obtained by camera calibration between pixel and the actual size, the diameter of sphere debris, the length and width of rectangular debris were achieved. The error calculated by comparing extraction parameters of accident picture with real size is within 5%.

Abstract: In order to research the injury of pedestrian collided with microbus windshield, the finite element model of pedestrian and windshield are established based on the characteristics of pedestrian collision with microbus windshield in traffic accident to simulate the collision process by ANSYS/LS-DYNA. In the condition of different impact velocities, HIC, TTI and stress intensity of pedestrian are studied in simulation test. The results illustrate that with the impact velocitys increasing the original impact energy, stress intensity, acceleration, HIC, and TTI increase. Also, the collision time is prolonged. Collision in head, the head of pedestrian would suffer serious injury with more than 29 km/h impact velocity. The chest would suffer serious injury with more than 25 km/h impact velocity in condition of colliding on chest.

Abstract: Students consider spatial visualization as one of the major difficulties at which they had to face in engineering studies. Most of them think that any effort leading to improve the understanding of such problem is welcomed. Taking this into account, an interactive application is developed in this paper in order to overcome the difficulties that engineering students traditionally find with regard to the visualization of ternary phase diagrams. To develop the didactic application diverse commercial software were used: (i) 3DStudioMax for designing the ternary equilibrium diagram and (ii) Quest3D for giving the tool a more intuitive and easy to use character. The result is a 3D virtual application which students can use for interacting in real time with a ternary diagram, e.g. changing point of view, rotating view, observing hidden zones of the diagram by applying transparency option, exploding view phases, cutting the diagram revealing isothermal sections and so on.

Abstract: Laboratory practices in technical degrees are usually crowed, what makes that many students waste the opportunity of putting into practice the knowledge acquired in theoretical classes. Taking this into account, an interactive virtual platform (IVP) is presented in this paper for enhancing students´ self-learning of one of the most commonly material tests used in engineering: the compression test for concrete samples. In order to carry out such innovative teaching approach, a computational modeling of a virtual materials laboratory was developed by authors including an interactive compression test machine. This way, by using this IVP, students can freely interact with the virtual compression machine during out of class study time. According to this approach, the aim of this computational application is essentially didactic, since (i) this tool allows students to get familiar with concrete compression test and, in this way, (ii) the knowledge acquired by means of such tool can be really useful to improve the performance in students´ learning during their later pressential laboratory practices.

Abstract: The Design Optimisation (DO) of Complex Systems is often a multidisciplinary task and involves multiple conflicting objectives and design constraints, where conventional methods cannot solve efficiently. This paper presents Advanced DO by Means of Evolutional Algorithms in two Real World Applications Electronics and Micro-Electro-Mechanical-Systems (MEMS). The former is presented in the context of multi-objective evolutionary synthesis and optimisation of analogue systems. As for the latter, DO of MEMS bio-mimetically is a very novel area of research, Which addresses the compelling change in the traditional landscape of the associated research disciplines by seeking to provide a novel biologically inspired computational platform for DO of micro-scale designs. This paper presents the latest advancements in the application of EAs in the DO of MEMS and analogue electronic systems and the emergence of the new area of ‘Multidisciplinary Optimisation'.

Abstract: The location of a checked part is one of the most critical and complicated problems in the checking fixture design (CFD) for thin-walled parts with less stiffness. The unreasonable layout of locators will give rise to the high deflection of the checked part and affect measure accuracy. Based on the “N-2-1” locating principle, an optimization method is presented to determine the locator layout, where the finite element method (FEM) is used to calculate the maximal deformation of the work piece which is used to be an objective function of optimization, and the Particle Swarm Optimization (PSO) with fine performance of global convergence is adopted as an optimization solver to seek for the optima. Finally, a case study is presented to verify the proposed method.

Abstract: This work describes a fuzzy expert system for rough turning. In order to automate unmanned turning, safety of the process must be ensured. In addition, any quality requirements should be fulfilled and, within these constraints, productivity maximized. The traditional approach in adaptive control of machining is to keep a measured quantity, such as power, within acceptable limits. However, there have been some studies measuring distinct phenomena in machining and identifying “cutting states” based on the phenomena. By identifying cutting states corresponding to phenomena monitored by human experts, it is possible to construct an intelligent machining system emulating the decision making of a human expert. This paper concentrates on defining the requirements for the inference part of such of an intelligent machining system. This work concentrates on both functional requirements, such as capability to take into account specific cutting states. The existence of process monitoring subsystems which detect and measure the cutting phenomena is assumed. As a result, a Sugeno-type fuzzy control is suggested, and feasibility and the level of completeness of such a system are discussed and issues requiring further study are identified.

Abstract: Modern, organic shaped, building façades are often created by joining together hundreds of flat panels, resulting in high production complexity. To reduce cost it is important to design the façade using the fewest possible unique panels. Each unique panel increases design and production times so using many repeated panels enables batch production, lowering cost. To optimise the panel layout with the fewest unique panels a ‘point equilibrium’ algorithm has been developed to position the corners of the panels (nodes) on a parametric surface. In the developed theory a set of hypothetical, electrically charged particles is randomly placed upon the façade surface and allowed to repel each other. They eventually settle into an equilibrium position, with similar distances between adjacent nodes and hence produce a large number of similar triangles. An example of a façade demonstrating the practicability of this technique for constructing panel layouts is given.

Abstract: This research explores how successfully melting and laser based additive manufacturing (LAM) process functions in the manufacture of fractal-like micro channel heat transfer devices. Different micro channels are studied worldwide and the studies at Lappeenranta University of Technology (LUT) aim to utilize micro channel geometries in heat transfer applications to solve cooling problems related to green technologies. Power electronics, micro-reactors, and fuel cell applications are a part of this development. Many of these technologies suffer from high, local heat fluxes. New energy production and vehicle systems can no longer be cooled only by air or water based liquid, because the growing power densities have reached the limits of air and water cooling. The goal of the work is to find an answer to the following question; what is the capability of the LAM process when manufacturing fractal like micro channels The study shows result of manufacturability tests of the micro-channels and gives recommendations for further study. Based on the manufacturing tests and literature findings, it can be stated that the used LAM process does not fully qualify for the manufacture of the micro channels in heat transfer devices at the moment. Process can be considered for manufacturing channels on a larger scale.