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Technical Vocational Education and Training (TVET) colleges are career-focused educational institutions designed to equip students with lifelong technical skills thereby contributing significantly to economic growth. The purpose of this study was to investigate mechanical engineering equipment in three TVET colleges in three South African provinces. The three provinces included in the study were Gauteng, Limpopo, and Free State. The equipment was investigated in an effort to integrate virtual and cyber-physical learning. The research utilized interviews with campus managers and senior lectures on Engineering and Related Design (ERD) to acquire data. A structured questionnaire was also distributed to former ERD students who are currently employed in the mining industry. The equipment of TVET colleges was contrasted to that of the mining industry. According to the research, TVET college equipment is outdated and inadequate, and their practical assessments are not routinely updated. The colleges do not yet have a virtual and cyber-physical learning system in existence, but preparations have been made. However, no intentions for the practical portion of the studies using virtual systems have been considered. The study affirms the need for virtual learning, Virtual Reality (VR), and Augmented Reality (AR) technologies to help students learn about current technology equipment used in the mining industry, as well as to provide sufficient time for practical learning. [ABSTRACT FROM AUTHOR]

In the optimization area, particle swarm optimization is an excellent optimization algorithm. It influenced thru position and velocity update of the particles. Particles velocity update significantly depend on its factor inertia weight (with previous velocity) and acceleration coefficients (with cognitive and social components). Also, PSO has various advantages like simplicity and fast convergence. However, PSO easily trapped into local optima due to simple search procedure. To improve the presentation of PSO, this article advises an updated-PSO (U-PSO) for solving mechanical engineering design optimization problems. In U-PSO, novel parameters (inertia weight, acceleration coefficients and lively coefficient) for velocity update and position update equation are employed to retain exploitation and exploration. To verify the efficiency and robustness, proposed U-PSO applied to solve two complex mechanical engineering designs optimization problems. The experimental outcomes validate that the suggested U-PSO has significant advantages over the compared algorithms. [ABSTRACT FROM AUTHOR]

Oxidation of graphite components could influence their designed life in a high-temperature nuclear reactor. The oxidized regions could potentially lower the allowed stress capacity. The American Society of Mechanical Engineers rules for the design and construction of graphite-moderated reactors recommend that subsurface regions that might become excessively damaged by oxidation during reactor operation be identified and excluded from geometry and stress calculations. Identification of oxidation-affected regions is possible, in principle, through complex modeling exercises of reactor behavior during hypothetical accident scenarios coupled with graphite oxidation models, but this procedure may not have the precision needed for informed decisions. This paper proposes an alternate method, based on interpretation of a series of well-designed oxidation experiments, which could augment the designer's tools. The procedure is illustrated by data on oxidation by air of several graphite grades (NBG-18, PCEA, IG-110, R4-650) that are corroborated with independent literature information, when available. The Wichner model for graphite oxidation used for this analysis provides conservative results that could be quickly implemented in the design process. [Display omitted] [ABSTRACT FROM AUTHOR]

IFMIF-DONES (International Fusion Materials Irradiation Facility – DEMO Oriented Neutron Source) is a fusion materials testing facility that is currently being designed under the framework of a work package of the EUROfusion Consortium. It will use a 125 mA at 40 MeV deuteron beam to generate a high neutron flux through L i (d , x n) stripping nuclear reactions in a liquid lithium target. The High Energy Beam Transport line (HEBT), the most upstream system of the IFMIF-DONES accelerator, is responsible for the guidance and shaping of the beam towards the target. Additionally, during commissioning periods, the HEBT is also responsible for diverting the beam, through the Beam Dump Transport Line, to the Beam Dump for testing purposes. The HEBT is spread along different rooms and zones: the Accelerator Vault, the Radiation Interface Zone (RIZ), and Target Interface Room (TIR). The engineering design of the HEBT components situated within the TIR and RIZ has been updated to satisfy new requirements, with a focus on ensuring the protecting of the Fast Isolation Valve (FIV) from the backscattered radiation from the target. These modifications include relocating the FIV from the TIR to the RIZ, adjusting the building layout to accommodate the new FIV module, configuring an enclosure cabinet for the RIZ, and adding local shielding to extend the lifetime of the FIV seal actuators. This work describes the current status of these TIR and RIZ engineering design, including radioprotection, commissioning and maintenance plan, beam diagnostics devices, beam dynamics and new remote handling approaches, as well as the layout and integration of the required components along the beamline. The TIR and RIZ are critical areas for IFMIF-DONES , and their design and operation must be compliant with functional, reliability and safety requirements. The updated design addresses potential issues and enhances the facility's overall functionality. • Collimator redesigned with new coolant fluid for the near TS safety measures. • TIR layout shift to two LRU frees space for new elements. • TIR-RIZ wall thickness reduced by one meter for space. • Enclosure cabinet in RIZ stores argon atmosphere for the FIV. • FIV lifespan doubled by implementing local shielding strategies. [ABSTRACT FROM AUTHOR]

To address conflicts arising during the innovative product design process, a dynamic evolution of conflicts and their relationships leads to the emergence of a new set of conflicts termed as "conflict flow." Initially, a product elemental network is created by analyzing the relevance of the improved product. The elemental nodes in this network undergo extensible conduction transformation which helps extract elemental conduction paths and identify conflicts. Subsequently, a scale-free conflict network is constructed using graph theory, and key conflicts are determined and resolved using TRIZ tools. Through iterative iterations, the conflict flows in the improvement design process are discovered and resolved. Furthermore, this research proposes a method for elemental conduction transformation and conflict determination rules based on conduction paths. It also describes the processes involved in constructing both the elemental network and the scale-free conflict network. Ultimately, the study establishes an iterative construction process model for conflict flow networks based on Extensible Conduction Transformation. To demonstrate its effectiveness, a case study is conducted involving the improvement design of an engineering mechanical Lead-acid battery plate testing equipment. [ABSTRACT FROM AUTHOR]

• An efficient robust topology optimization method for mechanical metamaterial. • Double-layer mesh technology improves the efficiency of topology optimization. • The impact of size uncertainty on topology optimization design is quantified. • Multiple mechanical metamaterials have been designed. With the increasingly stringent functional requirement of advanced equipment, it is crucial to design materials and structures with special properties. Improving optimization efficiency and shortening the design cycle are widely concerned as important scientific issues. This paper proposes a novel double-layer mesh-driven robust topology optimization strategy for mechanical metamaterials under size uncertainty. A double-layer mesh technology that establishes a mapping relationship between structural response and sensitivity information is developed, which greatly improves computational efficiency. The influence of size uncertainty is considered in topology optimization, and the robust design of mechanical metamaterials is realized. Various metamaterial designs are realized by solving optimization models based on sensitivity information. These can provide technical support and design references for the engineering application of mechanical metamaterials. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Heat sinks based on standard and novel, non-standard morphologies were designed using parametric modelling and computational optimization. • To allow their cross-morphological performance comparison, equity was established between them with regard to (thermal) mass. • The heat sinks were compared in a passive cooling application using numerical simulation and experimental methods. • Some heat sink morphologies performed more efficiently than others in the passive cooling application. • The approach to cross-morphological performance comparison is shown to be viable, despite shortcomings in technologies used. Cross-morphological performance comparisons in mechanical engineering design may well resemble comparisons of apples and oranges. They are meaningful only if pertinent properties shared across compared morphologies (so-called tertia comparationis) are identified, and equity with regard to these properties is established. This article demonstrates such an approach with the use of parametric geometry modeling, optimization, and additive manufacturing, enabling a thermal performance comparison of different heat sink morphologies, using both steady-state numerical simulation and experimental evaluation, by establishing equity across the compared heat sinks in terms of (thermal) mass. Limitations in additive manufacturing precision, as well as inconsistencies between numerical simulation and experimental evaluation results, were encountered in this case study. Likely resulting from the heat sinks' thermal properties on the additive manufacturing process and the simulation environment's disproportionate reliance on convection surface area, these limitations and inconsistencies will likely diminish as additive manufacturing and numerical simulation technologies improve. The cross-morphological comparison approach presented here is shown to be viable in principle and may inform decision-making in applied mechanical engineering design research and practice. [ABSTRACT FROM AUTHOR]

In mechanical engineering, designers have to review a designed artefact iteratively with different domain experts, e.g. from manufacturing, to avoid later changes and find a robust, optimized design. To support the designer, knowledge-based engineering offers a set of approaches and techniques that formalize and implement engineering knowledge into generic product models or decision support systems. An implementation which satisfies especially the concurrent nature of today's design processes and allow for multi-objective decision-making is multi-agent systems. Such systems consist of entities that are capable of autonomous action, interact intelligently with their environment, communicate and collaborate. In this paper, such a multi-agent system is discussed as extension for a computer-aided design software where the agents take the role of domain experts, like e.g. manufacturing technologists and make suggestions for the optimization of the design of mechanical engineering parts. A focal point is set on the collaboration concept of the single agents. Therefore, the paper proposes the use of an action-item-list as central information and knowledge sharing platform. [ABSTRACT FROM AUTHOR]

The manufacturing of moulds and dies requires smooth surfaces and high-quality. This way, the surface roughness is an essential parameter in finishing milling to improve the quality of injected products, such as cell phones, laptops, aerospace and automotive parts which very much depend on the finishing of the moulds. Thus, this paper aims to robust optimisation of surface roughness of AISI H13 hardened steel in the finishing milling using ball nose end mills, by using a combination of methodologies such as robust parameter design (RPD), response surface methodology (RSM), normal boundary intersection (NBI), and mean square error (MSE). Based on this, eight input factors were used in the experimental tests, being four control factors (feed per tooth, axial depth of cut, radial depth of cut, and cutting speed) and four noise factors (tool overhang length, workpiece tilt angle, tool flank wear, and cutting strategy). The surface roughness evaluated in Ra pattern was measured in two cutting directions: in tool feed rate direction (Ra_f z) and in radial depth of cut direction (Ra_a e). The results showed that it was possible to generate a convex and equispaced Pareto frontier to MSE functions of surface roughness Ra and that the achieved optimum decrease the sensitivity of the milling process using ball nose end mills to the variability transmitted by the noise factors. • This paper presented a methodology to the bi-objective robust optimisation of surface roughness obtained by finishing milling of AISI H13 hardened steel. Since the mould and die market is becoming more demanding and competitive, the results achieved with this methodology are essential to attain a competitive advantage in the mould and die industry. • This experimental design and data collection will show moulds and dies manufacturers in the field of mechanical engineering design the relationship and effect between the cutting tool, the workpiece surface roughness and the machining parameters. • This unique multivariate experimental design considers eight factors that potentially influence the surface roughness of AISI H13 hardened steel in the finishing milling using ball nose end mills. • The obtained results show that it was possible to generate a convex and equispaced Pareto frontier to MSE functions of surface roughness Ra and that the achieved optimum lessens the sensitivity of the milling process using ball nose end mills to the variability transmitted by the noise factors. • The RPD-NBI-MSE methodology used in this paper may be applied in other manufacturing processes as a bi-objective robust modelling and optimisation procedure. [ABSTRACT FROM AUTHOR]

Previous research has demonstrated the benefit of higher levels of cognitive style diversity and task-specific self-efficacy beliefs on team performance in complex tasks. This study aims to add to this growing body of literature by exploring the effects of both cognitive diversity and the self-efficacy beliefs of design teams on final design solutions. The final designs produced by 55 student design teams in a junior-level mechanical engineering course were analyzed, and measures of team-level cognitive diversity and task-specific self-efficacy beliefs were collected. Results indicate that higher cognitive diversity and aggregate engineering design self-efficacy levels of design teams significantly impact final design characteristics; aggregate creative self-efficacy had no effect on design characteristics. Highlights • Data from 55 student design teams and final designs compared. • Higher levels of cognitive diversity significantly affect final designs. • Aggregate engineering design self-efficacy significantly affect final designs. • Aggregate creative self-efficacy did not significantly affect final designs. [ABSTRACT FROM AUTHOR]

In the context of mechanical engineering design, the field of machine learning accelerated topology optimization is dominated by image-based models trained in a supervised manner on datasets with a limited diversity of boundary conditions. State-of-the-art methods show poor generalization capabilities and are strongly coupled to finite element mesh resolution, hindering scalability. In this paper, we leverage the explicit topology parameterization of the moving morphable components (MMC) framework to train a deep learning model that directly generates geometric design variables using a model architecture that is independent of the finite element mesh used for structural analysis. The developed model is trained on a large dataset of boundary conditions. Despite achieving state-of-the-art regression loss, evaluations reveal that direct-design approaches generate topologies with poor mechanical performance. Specifically, the model-generated topologies have, on average, a stiffness 11.48% lower than conventional MMC designs, as evidenced by in-distribution and out-of-distribution test samples. We demonstrate that this is due to the incompatibility between the regression loss function typically used in literature and the topology optimization objective of compliance minimization. To address this issue, we propose a novel acceleration approach that leverages the trained model to generate improved initial designs for conventional optimization. Specifically, the deep learning model is used to generate an initial design, which is then refined by conventional optimization to arrive at a final, optimal design. This approach shows a computation time-saving of 36.84% without sacrificing the final mechanical performance of the optimal topology compared to conventional optimization starting from a uniform initial layout. [ABSTRACT FROM AUTHOR]

Auxetic materials and structures have been attracting attention due to their extraordinary mechanical properties that stand out due to their high capacity to absorb energy. Some types of auxetic tubular structures have been studied and designed in diverse engineering fields such as mechanical, aerospace and medical. This manuscript cites more than a hundred papers containing the definitions, designs, structural analyses and optimization, mechanical properties, and specific applications of tubular design of auxetic structures. It can be noted from the present paper that additive manufacturing has been one of the most common manufacturing techniques used in many cases to manufacture tubular structures, and numerical analysis was essential to analyzing the behavior of the structures. The purpose of this paper is to assist researchers and engineers in using the methodology step by step to develop and apply auxetic tubular structures. • A review of auxetic tubes: definitions, optimization, properties, and applications. • Discussion about the potential applications of auxetic tubular structures. • Design and mechanical behavior of tubular auxetic structures. • Manufacturing trends of general auxetic structures and auxetic tubes. • Challenges and future directions on the auxetic tubes. [ABSTRACT FROM AUTHOR]

The Young's Double-Slit Experiment (YDSE) optimizer is a newly developed swarm intelligence algorithm inspired by Young's double-slit experiment that reveals the wave nature of light. Due to its simple structure and efficiency, the researchers employed the algorithm to address real-world optimization problems in multiple domains. However, in large-scale mechanical and engineering applications, it still needs to balance exploration and exploitation effectively and easily fall into local optimum. Therefore, in order to ameliorate these shortcomings, a multi-strategy improved YDSE optimizer named IYDSE is developed in this study. In IYDSE, introducing the Bernoulli map strategy ensures a higher quality initial population in the initialization, thus improving the convergence speed. Then, Levy flight is utilized as a local development engine to avoid local search stagnation of the optimal solution during optimization. In addition, mirror reflection learning is designed to enhance group diversity. Finally, the information entanglement strategy is introduced to enhance the information exchange between light and dark fringes, thus balancing the exploration-development capability. The superiority of the proposed IYDSE is comprehensively demonstrated by comparing it with state-of-the-art algorithms on the CEC2019 and CEC2020 test suites, respectively. Meanwhile, the practicability of IYDSE is also verified by solving five specific engineering design cases and 50 different types of engineering optimization suites. Finally, the IYDSE algorithm is applied to three truss topology optimization problems. The experimental results demonstrate the applicability and development potential of the proposed algorithm in practical engineering applications. Therefore, IYDSE is potentially an effective and competitive algorithm for solving applied mechanics and engineering. [ABSTRACT FROM AUTHOR]

This paper is written in honor of my long term friend and mentor Professor Bernard Roth who spent over six decades in Academic contributions devoted to Kinematics, Dynamics, Control, and design of computer controlled mechanical devices. He is continuing actively in his work from the famous school Hasso Plattner Institute of Design cofounded at Stanford (popularly known as d.school). As an Academic Director he is active in Creativity in Design. This paper explores the idea of Creativity directly from Science of 17th–18th centuries in place of Engineering evolved by Professor Timoshenko at Stanford in early 20th century at the time of rapid expansion of rotating machinery from de Laval in 1882. An example of design that involves extreme temperature ranges, magneto hydrodynamics and optimization in a fusion reactor to produce tritium fuel will be described. [ABSTRACT FROM AUTHOR]

In recent years, bio-based covalent adaptable networks (CANs) and vitrimers have developed rapidly in order to meet the renewable and sustainable requirements. It should be emphasized that the performance of the network need be upgraded and optimized to substitute petroleum-based polymers. Herein, a series of high-performance bio-based polyurethane were synthesized containing castor oil, isosorbide, vanillin derivative and 4,4′-Dicyclohexylmethane diisocyanate. By fine-tuning the bio-based diols, the hydrogen bond distribution and the crosslink density of the network were adjustable. The thermal mechanical properties and stress relaxation properties of the bio-based polyurethane were optimized. The bio-based polyurethane CANs shows tensile strength of 38.1 MPa, elongation at break of 243% and toughness of 55.7 MJ m−3, which is outstanding among most reported bio-based CANs. In addition, the polymer has excellent water resistance, shape memory and re-deformability. Due to the dissociation of imine bonds under mild acid conditions, the carbon fiber composite can readily degrade in mixed solvent for 3 h at 60 °C and the properties of recycled carbon fibers are highly preserved. Fabrication of extraordinary mechanical properties, reprocessably, and degradable polyurethanes through network structure design. [Display omitted] • Nonplanar rigid ring of isosorbide brings extraordinary mechanical properties to bio-based polyurethane CANs. • Adjusting the ratio of diols can tune the degree of cross-linking and distribution of hydrogen bonds in the networks. • Isosorbide can also improve fluidity of the network and lower activation energy. • CF composites can be chemically degraded under mild conditions for non-destructive recycling of CF. [ABSTRACT FROM AUTHOR]

Sketch-Based Modeling (SBM) is a field of study that focuses on the automatic creation of 3D models from freehand drawings. Today, two related branches coexist: one aimed at facilitating input for 3D content creation, and the other aimed at routing engineering designs into CAD/CAM/CAE. The latter is the goal of this position paper. Early attempts concentrated on the problem of line-drawing interpretation , but efforts switched toward geometric reconstruction as the "inverse projection" problem became the most challenging step to produce 3D models from 2D line-drawings. The term SBM was popularized when sketches began to displace line-drawings as main input. In the context of engineering design, interest in SBM has somewhat decreased, as studies have shown that current SBM tools are not as usable as paper and pencil sketches, nor do they yet provide any additional value to traditional media. Furthermore, engineers feel reasonably comfortable with current Mechanical CAD (MCAD) paradigms based on parametric modeling, and fail to recognize the potential benefits of interacting with computers via sketches. However, new technological trends such as personal fabrication and the democratization of CAD and manufacturing can significantly benefit from improved SBM tools. In this paper, we conduct a meta-review of the SBM literature which we view as a combination of three elements: geometry (shape), psychology (perception), and engineering (function). We advocate for a new approach to SBM based on reformulating the weights of these elements as an approach for searching the set of intentions in sketches conveyed through cues which, when perceived, reveal regularities and features of the object. Finally, we consider quality of CAD models not just as error-free models, reusable models, or even models that convey design intent, but models that consider these interrelated aspects as a whole. B-Rep models produced by current SBM approaches are "dumb models" without parametrization or procedures required to enable reusability and ensure that the design intent of the sketch is properly conveyed. We advocate for improved analysis approaches aimed at revealing higher-level design information embedded in engineering sketches, as a critical stage to generate richer 3D MCAD models. [Display omitted] • A review of Sketch-Based Modeling (SBM) for Engineering Design is provided. • Two different branches of SBM research coexist: one geared toward "artistic" purposes and the other governed by "engineering" principles. • The two branches must be studied separately, because of the fundamentally different goals of artistic vs. engineering sketches and the different nature of the 3D models that must be generated. • While the automatic conversion of artistic sketches into 3D models has made significant progress in recent years, the problem of producing CAD models with controllable, semantic, and parametric solid geometry has not yielded significant contributions to the scholarly literature. • Future opportunities, research directions, and recommendations on SBM approaches for engineering design are discussed. [ABSTRACT FROM AUTHOR]

The Monte Carlo method is widely used for the estimation of uncertainties in mechanical engineering design. However, while flexible, this method remains impractical in terms of computational time and scalability. To bypass these limitations, other more efficient approaches such as the Galerkin stochastic finite element method (GSFEM) or the collocation method have been proposed. GSFEM provides accurate output statistics, has the advantage of being sampling independent and can be modular in terms of operations, albeit code intrusive. While linear elasticity has been extensively covered in the literature, the application of GSFEM to nonlinear mechanical behaviour remains relatively unexplored, in part due to the difficulty to capture nonlinear effects with the traditional GSFEM interpolants. To this end, we propose a seamless and efficient modular framework avoiding the need to know a priori the material law. In particular, the method makes use of a wavelet based formulation able to capture simultaneously continuous and discontinuous behaviours, and stochastic operators are proposed to straightforwardly adapt any material model. Finally, the flexibility of this approach is illustrated with two problems: (i) a 3D hyperelastic example with nonlinear behaviour arising from buckling uncertainty, and (ii) the evaluation of the displacement of a point within a structure based on how much of the external accessible structural deformation is known. • A stochastic finite element method framework is presented. • A stochastic algebra library is provided for easy integration in FE code. • Polynomial chaos, Haar and wavelet expansions are considered. • Wavelet expansion is shown to capture mixed smooth/non-smooth problems. [ABSTRACT FROM AUTHOR]

Abstract: New methods and tools have been developed the last years to improve the understanding of gear meshing. Mechanical industries attach growing attention to the dynamic behavior of mechanical transmissions, including vibration and noise that result. The transmission error of the gear, which measures the intensity of one of the main causes of dynamic phenomena, can be considered as a relevant indicator of gear performance. This paper presents a new design method of spiral bevel gears, the objective of this method being to reduce their quasi-static transmission error. The proposed approach is based on an optimization process including loaded meshing simulations. The simulation model has been evaluated using a helicopter tail gearbox as bench test. Measurement results are given, showing a good correlation with predictions. [Copyright &y& Elsevier]

Target design methodologies (DfX) were developed to cope with specific engineering design issues such as cost-effectiveness, manufacturability, assemblability, maintainability, among others. However, DfX methodologies are undergoing the lack of real integration with 3D CAD systems. Their principles are currently applied downstream of the 3D modelling by following the well-known rules available from the literature and engineers' know-how (tacit internal knowledge). This paper provides a method to formalize complex DfX engineering knowledge into explicit knowledge that can be reused for Advanced Engineering Informatics to aid designers and engineers in developing mechanical products. This research work wants to define a general method (ontology) able to couple DfX design guidelines (engineering knowledge) with geometrical product features of a product 3D model (engineering parametric data). A common layer for all DfX methods (horizontal) and dedicated layers for each DfX method (vertical) allow creating the suitable ontology for the systematic collection of the DfX rules considering each target. Moreover, the proposed framework is the first step for developing (future work) a software tool to assist engineers and designers during product development (3D CAD modelling). A design for assembly (DfA) case study shows how to collect assembly rules in the given framework. It demonstrates the applicability of the CAD-integrated DfX system in the mechanical design of a jig-crane. Several benefits are recognized: (i) systematic collection of DfA rules for informatics development, (ii) identification of assembly issues in the product development process, and (iii) reduction of effort and time during the design review. [ABSTRACT FROM AUTHOR]

Abstract: In many underwater missions, it is necessary for the autonomous underwater vehicle (AUV) to be stationed at a particular position and orientation to carry out tasks like inspection, opening/closing of valves, or repair of underwater installations. The ability of an AUV to maintain its position and orientation dynamically is termed as dynamic station keeping. Being a free-floating device, dynamic station keeping is not natural to most of the AUVs. This becomes more complex when the vehicle is underactuated and is not neutrally buoyant. In this paper, the problem of dynamic station keeping of an underactuated flat-fish type AUV is analysed and a new method of station keeping is proposed with an addition of dedicated thrusters. Effect of introduction of additional thrusters on tracking performance has been analysed and a modular configuration (using retractable thrusters) is proposed to reduce its influence on tracking control. The effects of underwater current magnitudes and angle of incidences on the station keeping performance are also analyzed. A comparative analysis on power consumption during station keeping is presented to prove the effectiveness of the proposed modular configuration. [Copyright &y& Elsevier]

Abstract: Early stage design of precision flexure systems that utilize strain-based displacement sensing is difficult due to the strong coupling between the mechanical and sensing subsystems. Traditional tools for flexure system and compliant mechanism synthesis are not capable of simultaneously optimizing the mechanical and sensing subsystems. The building block synthesis approach developed in this work is the only tool capable of designing compliant mechanisms with integrated strain based sensing. Building block modeling allows for rapid synthesis and vetting of concepts. This approach also allows the designer to determine concept feasibility, identify performance limits and tradeoffs, and obtain 1st order estimates of flexure geometry. In short, this method enables one to find an optimal design and set first order design parameters. The utility of the building block approach is detailed in a case study detailing the synthesis and modeling of three different one degree-of-freedom translational stages that are all derived from the series and parallel addition of fixed-guided cantilever beam building blocks. [Copyright &y& Elsevier]

Abstract: In a compartment fire, the breakage and possible fallout of a window glass has a significant impact on the fire dynamics. The thermal breakage of glass depends on various parameters such as glass type, edge shading, edges conditions and constraints on the glass. The purpose of the present study is to investigate some of the key parameters affecting the thermal breakage of window glass in fire conditions using a recently developed and validated computer tool. Fallout is not within the scope of this study. Different boundary conditions of the glass pane (unconstrained and constrained) subjected to fire radiant heat are investigated. The analysis shows that to prevent glass thermal breakage, it is important to provide enough spacing between the frame and glass pane to accommodate the thermal expansion, and constraints on the glass structure should be avoided. The zones where the glass is likely to crack first are shown. The study also quantifies the effects of glass edge conditions on its thermal breakage in fire conditions; such analysis has not been reported in the literature due to its complexity and the statistical nature of edge flaws. The results show that an ordinary float glass mostly used in windows, with the “as-cut” edge condition would break later and is stronger than a ground edge or polished edge glass for the scenarios investigated. The study demonstrates how a predictive tool could be employed for a better understanding of thermal breakage of window glass in fires and for design guidance. [Copyright &y& Elsevier]

Abstract: In this paper engineering drawing techniques are examined with a particular focus on the use of the modulus concept in design. Modulus concept here means a unit of measure based on experience and relation to key attributes from which all the design corresponds. This approach appears to be more familiar in architecture; however, less so in mechanical engineering. To illustrate this a historical review of the modulus concept is given and its applicability for today''s mechanical engineering practise is shown. [Copyright &y& Elsevier]

Abstract: The integrated design method of series traction mechanism of heavy machinery was studied based on virtual prototyping. The overall research program was proposed. Furthermore, Based on this program, the computing system with the entity finite element based on ANSYS software and the computing system with equivalent beam element based on Matlab software were developed. Moreover, with two systems, for typical structure traction mechanism of heavy machinery, it was optimized. The study in the paper provides a new design method for design and development of series traction mechanism of heavy machinery. [Copyright &y& Elsevier]

Abstract: The composition and working principle of DCS system are introduced, as well as its configuration, function and basic language. An account of the design of auto-control system on dyeing machine is narrated, and the advancement of the system and the importance of cascade control are further put forward. Its control rate can achieve above 95%, which can reduce labor intensity and improve working environment. [Copyright &y& Elsevier]

Abstract: This paper describes the design and implementation of automatic controller tuning and model reference adaptive control (MRAC) to improve part quality in stamping and extends previous work on a manually-tuned fixed-gain process controller. Automatic tuning is described with a discussion of implementation issues in the presence of plant disturbances. Design of a direct MRAC, whose controller gains are continuously adjusted to accommodate changes in process dynamics and disturbances, is investigated, including simulation-based robustness analysis of the adaptation law and a consideration of constrained estimation in the recursive least squares algorithm to address practical implementation issues. The performance of the MRAC process controller designed through simulation is experimentally validated. Good tracking of the reference process variable (i.e., punch force), and significant part quality improvement in the presence of disturbances, is achieved. [Copyright &y& Elsevier]

Abstract: The energy consumed by an escalator can be logically subdivided into two main components. The first component depends on the vertical rise of the escalator and its mechanical and electrical design. This component has been denoted as the fixed power losses. It is the power that is drawn from the supply when the escalator is running unloaded (regardless of the direction of travel). The second component depends on the vertical rise of the escalator and the number of passengers using the escalator per day as well as their walking behaviour. This component has been denoted as the variable power losses for an upward moving escalator (or variable power gains for a downward moving escalator). The formulae used to calculate both components are derived based on power measurements on a large group of escalators in addition to a number of passenger count surveys on a selection of escalators (synchronised to the power measurement data). Further analysis is carried out into the phenomenon of passengers walking on escalators and its effect on the overall energy consumption. [Copyright &y& Elsevier]

Abstract: Augmented reality has been applied to develop augmented assembly systems. However, most reported studies used pre-defined assembly information; AR is predominantly used to display information and interactions between users and the augmented environment are limited. This paper presents 3D bare-hand interaction in an augmented assembly environment to manipulate and assemble virtual components. A hybrid method based on constraint analysis is presented, which interprets users’ manual assembly intents robustly without the need for auxiliary CAD information. Algorithms for assembly constraint recognition, assembly tool operations and assembly sequence evaluation have been formulated. An augmented assembly system has been developed in this research. [Copyright &y& Elsevier]

Abstract: Computer-Aided Design (CAD) applications provide design and engineering professionals with various computer-based tools to perform design activities. As efficiency is one of the most important requirements in most design tasks, in this article, we contribute a novel collaborative design approach to improving efficiency, where a complex design task can be divided and executed concurrently by multiple collaborative designers. This approach is particularly effective for design tasks where Boolean operations – widely supported by most CAD applications – are heavily used in design activities, such as architecture design, mechanical design and digital media design. We have designed and implemented a prototype system CoAutoCAD to test the approach and to demonstrate a variety of collaborative design activities. [ABSTRACT FROM AUTHOR]

Abstract: The verification and validation of engineering designs are of primary importance as they directly influence production performance and ultimately define product functionality and customer perception. Research in aspects of verification and validation is widely spread ranging from tools employed during the digital design phase, to methods deployed for prototype verification and validation. This paper reviews the standard definitions of verification and validation in the context of engineering design and progresses to provide a coherent analysis and classification of these activities from preliminary design, to design in the digital domain and the physical verification and validation of products and processes. The scope of the paper includes aspects of system design and demonstrates how complex products are validated in the context of their lifecycle. Industrial requirements are highlighted and research trends and priorities identified. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an analysis and synthesis method for a certain type of geared four-bar mechanism (GFBM) for which the input and output shafts are collinear. A novel analysis method is devised, expressions for the transmission angle are derived and charts are prepared for the design of such mechanisms. It is observed that the GFBM considered is inherently a quick-return mechanism. Large time ratios can be obtained with acceptable force transmission characteristics. During the working stroke, approximately constant angular velocity at the output link is observed. For the type of GFBM analyzed, direction of rotation of the input link affects the force transmission characteristics. [Copyright &y& Elsevier]

Abstract: To design a vehicle’s suspension system for a specific, well defined road type or manoeuvre is not a challenge any more. As the application profile of the vehicle becomes wider, it becomes more difficult to find spring and damper characteristics to achieve an acceptable compromise between ride comfort and handling. For vehicles that require both good on- and off-road capabilities, suspension design poses a significant challenge. Vehicles with good off-road capabilities usually suffer from poor on-road handling. These vehicles are designed with a high centre of gravity due to the increased ground clearance, soft suspension systems and large wheel travel to increase ride comfort and ensure traction on all the wheels. All of these characteristics contribute to bad handling and increased rollover propensity even on good level roads. It is expect from these vehicles to have the same handling characteristics as a normal on-road vehicle. This paper analyses the use of an active anti-roll bar as a means of improving the handling of an off-road vehicle without sacrificing ride comfort. The proposed solution is simulated, designed, manufactured, implemented and tested to quantify the effect of the active anti-roll bar on both the handling and ride comfort of an off-road vehicle. [Copyright &y& Elsevier]

Abstract: Most weigh feeders are controlled by a PID control method, and it is desirable to achieve high performance with this PID control. The present paper discusses the application of a generalized predictive control (GPC)-based PID controller to a weigh feeder. In conventional methods, GPC-based PID controllers are designed using a step-type reference signal, but in control of a weigh feeder, a reference input to be followed by a measured signal is a ramp-type signal because the measured signal is discharged mass. Hence, control of a weigh feeder using a GPC-based PID controller is enhanced for tracking a ramp-type signal. Because GPC can be expressed by PID parameters, the proposed method can be easily adopted in various industries. Experimental results show that a weigh feeder is well controlled using the enhanced GPC-based PID controller. [Copyright &y& Elsevier]

Abstract: This paper presents an application of augmented reality for improving spatial abilities of engineering students. An augmented book called AR-Dehaes has been designed to provide 3D virtual models that help students to perform visualization tasks to promote the development of their spatial ability during a short remedial course. A validation study with 24 Mechanical Engineering freshmen at La Laguna University (Spain) has concluded that the training had a measurable and positive impact on students’ spatial ability. On the other hand, results obtained using a satisfaction questionnaire illustrate that AR-Dehaes is considered an easy to use, attractive, and very useful technique for students. AR-Dehaes has proved to be a very cost-effective tool insofar as it only required an ordinary PC with a webcam to be used. [Copyright &y& Elsevier]

Abstract: Thermo-mechanical detector arrays in the 160×120 array format are designed, fabricated, and tested. Detectors are composed of SiN x and TiN as absorbing layer, Al to form bimaterial legs, and integrated diffraction grating interferometer underneath each detector. The detector array is a passive component and the optical readout is performed remotely with a laser and CCD camera. All noise sources are considered in making a detailed noise equivalent temperature difference (NETD) estimation, which revealed <30mK NETD is achievable using >12-bit CCD camera for the readout. [Copyright &y& Elsevier]

Abstract: Designing an optimized composite laminate requires finding the minimum number of layers, and the best fiber orientation and thickness for each layer. To date, several optimization methods have been introduced to solve this challenging problem, which is often non-linear, non-convex, multimodal, and multidimensional, and might be expressed by both discrete and continuous variables. These optimization techniques can be studied in two parts: constant stiffness design and variable stiffness designs. This paper concentrates on the first part, which deals with composite laminates with uniform stacking sequence through their entire structure. The main optimization methods in this class are described, their characteristic features are contrasted, and the potential areas requiring more investigation are highlighted. [Copyright &y& Elsevier]

Abstract: Magnetorheological (MR) fluid is a manageable fluid that exhibits drastic changes in rheological properties and interchangeable depending on the applied magnetic field strength. The fluid is potentially advantageous to be employed in many applications. This paper presents the design of test equipment for the performance of compression and tension tests. Finite element method magnetics (FEMM) was used to analyze the magnetic field distribution through the MR fluid. The test equipment was constructed and modified according to the operational principles, conditions and simulation results. The tests were performed in a vertical direction to the DC magnetic field generated by a coil. Experimental results showed that the compressive/tensile stresses of MR fluids increased as the applied current increased. The test equipment was utilized to investigate the performance of the MR fluid in squeeze mode. [Copyright &y& Elsevier]

Abstract: We study targeted energy transfers (TETs) and nonlinear modal interactions attachments occurring in the dynamics of a thin cantilever plate on an elastic foundation with strongly nonlinear lightweight attachments of different configurations in a more complicated system towards industrial applications. We examine two types of shock excitations that excite a subset of plate modes, and systematically study, nonlinear modal interactions and passive broadband targeted energy transfer phenomena occurring between the plate and the attachments. The following attachment configurations are considered: (i) a single ungrounded, strongly (essentially) nonlinear single-degree-of-freedom (SDOF) attachment—termed nonlinear energy sink (NES); (ii) a set of two SDOF NESs attached at different points of the plate; and (iii) a single multi-degree-of-freedom (MDOF) NES with multiple essential stiffness nonlinearities. We perform parametric studies by varying the parameters and locations of the NESs, in order to optimize passive TETs from the plate modes to the attachments, and we showed that the optimal position for the NES attachments are at the antinodes of the linear modes of the plate. The parametric study of the damping coefficient of the SDOF NES showed that TETs decreasing with lower values of the coefficient and moreover we showed that the threshold of maximum energy level of the system with strong TETs occured in discrete models is by far beyond the limits of the engineering design of the continua. We examine in detail the underlying dynamical mechanisms influencing TETs by means of empirical mode decomposition (EMD) in combination with wavelet transforms. This integrated approach enables us to systematically study the strong modal interactions occurring between the essentially nonlinear NESs and different plate modes, and to detect the dominant resonance captures between the plate modes and the NESs that cause the observed TETs. Moreover, we perform comparative studies of the performance of different types of NESs and of the linear tuned mass dampers (TMDs) attached to the plate instead of the NESs. Finally, the efficacy of using this type of essentially nonlinear attachments as passive absorbers of broadband vibration energy is discussed. [Copyright &y& Elsevier]

Abstract: Material selection for mechanical designs is an important task. Different approaches have been proposed to fulfill this job, so far. However, most of them work well with only quantitatively measurable properties of materials. Also, due to a wide range of materials available, the selection space finds a fuzzy characteristic. Therefore, here a simplified fuzzy logic approach is introduced to provide a powerful tool for easy dealing with the qualitative properties of materials and the corresponding fuzzy space. With this approach the volume of mathematics involved with the conventional methods reduces, considerably. The results show an excellent match with the Manshadi’s method. [Copyright &y& Elsevier]

Abstract: A great deal of effort has been invested to improve the performance and efficiency of mechanical systems which are composed of various components. In order to analyze the system with various performance requirements, the sequential configuration techniques based on the subsystems’ behavior are widely used. In the area of structural design, the evaluations under ultimate loads and vibration environments have been an important task. In order to determine the structurally optimal configuration for bearing the ultimate load and low vibrations, the design factors originating from both geometry and material must be incorporated in the analyses. This approach can be used for complicated structural analysis in which subsystems are initially incompatible and for an integrated design process with the feasible local flexibilities between system and subsystems. [Copyright &y& Elsevier]

Abstract: Uncertainty and variability modelling tools greatly enhance the value of virtual prototypes at the different design stages of a CAE process. The fuzzy analysis technique is suited to deal with models containing subjective non-deterministic parameters. This technique is finding its way to different disciplines of mechanical engineering. The objective of this paper is to increase the value of this technique in early stages of mechanical design procedures. For this purpose, new numerical procedures are proposed. First, the degree of influence is introduced. This new concept measures the relative effect of highly uncertain design properties on the performance of a design. Next, this paper proposes a new reduced optimisation scheme in order to improve the computational efficiency of the interval analysis, which is at the core of the implementation of the fuzzy technique. The practical applicability of the newly developed procedures is demonstrated on two numerical applications from the automotive industry. The analysed models represent the design at the conceptual stage, and contain parameters with a high and subjective level of uncertainty. The parametrised models are used to demonstrate the value and efficiency of the developed numerical procedures: significant parameters are identified using the degree of influence analysis, the optimal configuration is identified through an interval analysis based on the reduced optimisation scheme, and finally the fuzzy technique is applied as design space exploration tool. [Copyright &y& Elsevier]

Parallel structure robots have been receiving growing attentions from both academia and industries in recent years. This is due to their advantages over serial structure robots, such as high stiffness, high motion accuracy and high load-structure ratio. Control of a parallel robot, however, renders a difficult problem to control engineers. To obtain the same degrees of freedom (DOF), a parallel structure is more complex than a serial one, and so is its dynamic model in general. To effectively control a complex mechanical structure for precise and fast performance, an advanced controller embedded with the system''s dynamic model is usually desired. In cases of controlling parallel robots, however, the intensive computation due to the complexity of the dynamic model can result in difficulties in the physical implementations of the controllers for high-speed performance. To avoid heavy computation, simplified dynamic models can be obtained by applying simplification techniques, nevertheless, performance accuracy will suffer due to modeling errors. This paper suggests applying a general mechatronics design approach, i.e., the design for control (DFC) approach, to handle this problem. The underlying idea of the DFC approach is that, no matter how complex a system is, as long as its mechanical structure can be judiciously designed such that it can result in a simple dynamic model, a simple control algorithm may be good enough for a satisfactory control performance. As such, complicated controller design can be avoided, on-line computation load can be reduced and better control performance can be achieved. Through out the discussion in the paper, the design and control of a two DOF parallel robot is studied as an illustration example. Resulted control performances of several different mechanical designs derived from the same robot structure topology demonstrate the effectiveness of the DFC approach. [Copyright &y& Elsevier]

In this paper, we explore various options to classify technological knowledge for mechanical engineering designers. Classification is needed when technological knowledge is presented to designers in an automated knowledge management system (for example, a database that can be accessed by designers through the Internet). In particular, we draw from philosophy of technology, history of technology, and design methodology, to see what classifications can be made. It is not known whether such theoretical classifications are recognised by designers. In the empirical part of our study, we have submitted a number of optional classifications to active mechanical engineering designers to see what classification they would prefer as the basis for an automated knowledge-based system on the Internet. The outcome was that they recognised a classification that had been developed in the context of philosophical and historical studies, and even preferred that compared to more traditional disciplinary classifications. [Copyright &y& Elsevier]

Many different studies have stressed the importance of co-operation in engineering design. This paper is based on an empirical study carried out over 18 months and based on fieldwork where the researcher worked in a design team as a mechanical engineer. The question of product–process integration is particularly critical in mechanical engineering and requires the development of specific co-operative procedures. Our results stress the importance of artefacts as intermediary objects in the design process and more specifically in the development of co-operative processes. We developed a framework centred on three conceptual levels: