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This paper describes the effect of beam offsetting in finite element calculations. The effect is evaluated by considering two case studies involving beams, in which finite element analysis is performed with solid elements and with shell elements. It is seen that, under certain conditions, ignoring the beam offset can lead to erroneous results. Although the beam offsetting feature is available in most commercial codes, it is not always well documented. [ABSTRACT FROM AUTHOR]

In this paper, planar mechanisms with dyads are analyzed using Mathematica. First, a classification of dyads is introduced and then Mathematica packages for the analysis of the driver link and dyads are explained. The analysis provides a consistent coding scheme for planar mechanisms. The advantage of the group classification of a system lies in its simplicity. The solution of the whole system can then be obtained by composing partial solutions. This approach will eliminate the need to store complete mechanism information in a large database. [ABSTRACT FROM AUTHOR]

The flatness measurement of a large 2-D flat work- piece such as a satellite solar panel substrate is a key problem in its manufacturing process. Based on the current measuring methods and the actual engineering project, a new noncontact high-precision, low-cost large 2-D flat workpiece flatness measuring system is developed, in which the techniques of oblique optical triangle measuring structure, virtual measurement datum plane, and error self-correction are adopted. By means of the oblique optical triangle measuring structure that is first proposed, the measuring area and resolution of the measuring system can be greatly increased. Meanwhile, on the basis of the techniques of virtual measurement datum plane and error self-correction, the noncontact high-precision, low-cost flatness measurement can be realized on a nonprecise large metallic platform. Experimental results on the satellite solar panel substrate indicate the correctness and effectiveness of the proposed noncontact flatness-measuring system of the large 2-D flat workpiece. Although the specific application of the satellite solar panel substrate is presented in this paper, the proposed measurement techniques and measuring system could be applied independent of the nature or use of the large 2-D flat workpieces. [ABSTRACT FROM AUTHOR]

The current automotive electrical/electronic (E/E) systems are characterized by proprietary solutions, which seldom allow the exchange of applications between both automotive OEMs and their suppliers. It is especially difficult to change ECU suppliers or reuse the software in a new generation of products. Increasing functional requirements in automotive E/E vehicle development will significantly enhance the integration of novel functions. In order to satisfy the increasing requirements for the complex software development of automotive E/E system, implement the portability of application software modules and compatibility of ECU modules among different automotive OEMs and their suppliers, this paper presents an open design methodology based on quantum platform. An open architecture of automotive E/E system based quantum platform is established. Its principle and structures are described in detail. Finally, an automated mechanical transmission (AMT) system as a typical case is used to demonstrate the design process based on the proposed method. [Copyright &y& Elsevier]

Abstract: Fault tree analysis (FTA) is a technique that describes the combinations of events in a system which result in an undesirable outcome. FTA is used as a tool to quantitatively assess a system''s probability for an undesirable outcome. Time constraints from concept to production in modern engineering often limit the opportunity for a thorough statistical analysis of a system. Furthermore, when undesirable outcomes are considered such as hazard to human(s), it becomes difficult to identify strict statistical targets for what is acceptable. Consequently, when hazard to human(s) is concerned a common design target is to protect the system from single points of failure (SPOF) which means that no failure mode caused by a single event, concern, or error has a critical consequence on the system. Such a design target is common with “by-wire” systems. FTA can be used to verify if a system is protected from SPOF. In this paper, sufficient criteria for evaluating protection from SPOF for partially expanded fault trees are proposed along with proof. The proposed criteria consider potential interactions between the lowest drawn events of a partial fault tree expansion which otherwise easily leads to an overly optimistic analysis of protection from SPOF. The analysis is limited to fault trees that are coherent and static. [Copyright &y& Elsevier]

Abstract: Noise emitted by a vacuum cleaner suction unit has aerodynamic, mechanical and electromagnetic noise origins. The aerodynamically generated noise within the blower mostly prevails in the total emitted noise at design and off-design operations. The vaned diffuser built into the blower has an important effect on the aerodynamically generated noise and its spectra. Therefore, in this part of the paper, the effects of the vaned diffuser on the performance and noise characteristics have been measured and analysed at the design and off-design operation. Analysis of measurement results have shown that the built-in vaned diffuser has numerous disadvantages, including: increase in the rotational noise, increase in the non-rotational turbulent noise, especially at off-design operation, increase in production costs and reduction of the flow rate. Therefore, and due to variable operating conditions of the suction units built into a vacuum cleaner, it could be omitted or replaced by a vaneless one. [Copyright &y& Elsevier]

Abstract: The Bouc-Wen model, widely used in structural and mechanical engineering, gives an analytical description of a smooth hysteretic behavior. In practice, the Bouc-Wen model is mostly used within the following black-box approach: given a set of experimental input–output data, how to adjust the Bouc-Wen model parameters so that the output of the model matches the experimental data. It may happen that a Bouc-Wen model presents a good matching with the experimental real data for a specific input, but does not necessarily keep significant physical properties which are inherent to the real data, independently of the exciting input. This paper presents a characterization of the different classes of Bouc-Wen models in terms of their bounded input-bounded output stability property, and their capability for reproducing physical properties inherent to the true system they are to model. [Copyright &y& Elsevier]

This paper describes a modeling language that aims to provide a unified framework for representing control systems, namely, physical plants coupled with computer-based control devices. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows describing both control software and physical components using the same basic concepts, particularly those of capsules, ports, and protocols. Furthermore, it is illustrated how the well-known object-oriented specification language unified modeling language can be adopted, provided an adequate formalization of its semantics, to describe structural and behavioral aspects of control systems, related to both logical and physical parts. [ABSTRACT FROM AUTHOR]

Abstract: Three-dimensional shape retrieval is a problem of current interest in several different fields, especially in the mechanical engineering domain. There exists a large body of work in developing representations for 3D shapes. However, there has been limited work done in developing domain-dependent benchmark databases for 3D shape searching. We propose a benchmark database for evaluating shape-based search methods relevant to the mechanical engineering domain. Twelve different shape descriptors belonging to three categories, namely: (1) feature vector-based, (2) histogram-based, and (3) view-based, are compared using the benchmark database. The main contributions of this paper are the development of a new engineering shape benchmark and an understanding of the effectiveness of different shape representations for classes of engineering parts. Overall, it was found that view-based representations yielded better retrieval results for a majority of shape classes, while no single method performed best for all shape categories. [Copyright &y& Elsevier]

This paper describes a non-actuated glass-curtain wall-cleaning robot prototype that has been designed and realized based on some wall-climbing robots developed recently and common traits of glass-curtain walls of high-rise buildings. The robot hasn’t its own driving mechanism, but it can move on smooth glass surfaces depending on its own gravity and the lifting force of the trolley crane on the roof while adhering to the surfaces using dual vacuum suction cups. Obstacles, such as horizontal window frames, can be crossed while cleaning. The safety analysis ensures that the robot can work reliably. The analysis on characteristics of suction cups using fluidic network theory is to enhance the adhering capacity of the robot. The control system utilizes two-level computer control strategy to achieve the robot’s moving, cleaning and crossing obstacles. Experiments proved the robotic system is feasible and practical. [ABSTRACT FROM AUTHOR]

This paper proposes a method by which material in- homogeneity may be taken into account in a reliability calculation. The method employs Monte-Carlo simulation; and introduces a material strength index, and a standard deviation of material strength to model the variation in the strength of a component throughout its volume. The method is compared to conventional load-strength interference theory. The results are identical for the case of homogeneous material, but reliability is shown to reduce for the same load as the component volume increases. The case of a tensile bar is used to explore the variation of reliability with component volume. [ABSTRACT FROM AUTHOR]

As the complexity of automotive vehicles increases, so does the need for high calibre, multi-disciplined engineers. This paper provides a discussion into the type of control systems found in modern automotive vehicles and the skills required by the engineers working in this mechatronic system environment. [ABSTRACT FROM AUTHOR]

Despite a world-wide interest in mechatronics education, there is no clear and consistent understanding of what mechatronics is, nor how, and at what level, it should be taught. The key challenge for mechatronics course designers is seen as that of ensuring an appropriate balance between depth and breadth while providing opportunities to enable students to practise integration. The paper discusses this in relation to a number of mechatronic themes. Factors influencing the design, structure and content of a mechatronics programme are discussed and suggestions made as to the possible core content of such a programme. [ABSTRACT FROM AUTHOR]

Traditional dynamic modelling of multidisciplinary systems involves separate sets of analysis skills for each domain. Bond Graphs embrace commonality, providing a concise unified means of system representation and a systematic analysis method. This paper introduces Bond Graphs, benefits of acausal component models, and software for automated equation generation and simulation. [ABSTRACT FROM AUTHOR]

The paper describes the utility of a low cost, 1 m2 by 2 m forced ventilation, micro-climate test chamber, for the support of research and teaching in mechatronics. Initially developed for the evaluation of a new ventilation rate controller, the fully instrumented chamber now provides numerous learning opportunities and individual projects for both undergraduate and postgraduate research students. [ABSTRACT FROM AUTHOR]

In an effort to attract talented high school students to the engineering profession, Milwaukee School of Engineering (MSOE) has developed a number of outreach programs. The most successful of these, entitled‘Focus on the Possibilities’, allows the student to select a specific engineering discipline and experience a week-long program in their chosen area. This paper details the program developed by the Mechanical Engineering Department at MSOE to attract talented high school students to the mechanical engineering discipline. The program consists of an integrated design/build/test experience, centered around the design of a scale-model race car. The program is facilitated by two key technologies available at MSOE: solid modeling and solid freeform fabrication (rapid prototyping). Through creative use of these enabling technologies, the students are able to take the design of their racer from concept to realization and testing in the span of the week-long program. [ABSTRACT FROM AUTHOR]

The use of random variables and the application of probabilistic techniques for power system analysis has become an important issue due to the increased uncertainties faced by modern power systems. In the techno-economic analysis of an installation, especially at the design stage, several discrete values have to be considered for each variable, such as voltage, power, power angle, etc. Therefore, in handling such problems, it is advisable to use random variable ranges as explained in the paper taking the area of power transmission engineering as an example. [ABSTRACT FROM AUTHOR]

The limiting situation of a pair of approaching circular arc crack tips in a homogeneous medium is examined to draw analogies with circular disc problems. As the crack tips approach each other, the narrow material ligament bridging the crack tips controls the stresses, stress intensity factors and energy release rates. In particular, this ligament sets up the length scale for singularity analysis for a given radius of the arc crack. Following a detailed analytical examination of approaching crack tips, a photoelastic visualisation of the stress field is presented. Experimental isochromatics are also compared with theoretical predictions for some specific cases. Finally, based on the ideas developed in this paper, existing notions on interacting cracks and cavities treated in the literature are reinterpreted. [ABSTRACT FROM AUTHOR]

Lot streaming is the process of splitting a job or lot to allow overlapping between successive operations in a multistage production system. This use of transfer lots usually results in a substantially shorter makespan for the corresponding schedule. In this paper, we study the discrete lot streaming problem for a single job in no-wait flow shops. We present a new linear programming formulation for the problem. We show that the optimal solutions are the same for the m x 2 case with or without no-wait constraints. We also present a fast, polynomial-time solution method for this case. For the general case, we prove that any solution which is 'close' to the continuous optimal solution will be a good approximation for the discrete problem. This property allows us to present two quickly obtainable approximations of very good quality. [ABSTRACT FROM AUTHOR]

In all branches of engineering, from the earliest times to the present and into the future, there exist only two fundamental approaches to solve problems that arise in the discovery of knowledge and its application to society's needs: a. Theoretical modeling. b. Experimental measurement In engineering, this is true regardless of the discipline (mechanical engineering, electrical engineering , chemical engineering, etc.) or the engineering function (design, manufacturing, etc.). While some problems are adequately treated by using only theory, or only experimentation, most require judiciously chosen mix of these techniques. This is the situation that is presented in this paper, where besides to realize the theoretical analysis of the problem are used experimental measurements to obtain information that allow us to determine the cause of failure in the threaded fasteners of an assembled joint. [ABSTRACT FROM AUTHOR]

Focuses on various issues concerning the "Journal of Solar Energy Engineering". Accomplishment of the editors of the journal; Expansion in the number of papers published; Diversity of topics discussed; Announcement of Aldo Steinfeld's assumption of the post of Editor.