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Engineering design often involves representation in at least two levels of abstraction: the system-level, represented by lumped parameter models (LPMs), and the geometric-level, represented by distributed parameter models (DPMs). Functional design innovation commonly occurs at the system-level, followed by a geometric-level realization of functional LPM components. However, comparing these two levels in terms of behavioral outcomes can be challenging and time-consuming, leading to delays in design translations between system and mechanical engineers. In this paper, we propose a simulation-free scheme that compares LPMs and spatially discretized DPMs based on their model specifications and behaviors of interest, regardless of modeling languages and numerical methods. We adopt a model order reduction (MOR) technique that a priori guarantees accuracy, stability, and convergence to improve the computational efficiency of large-scale models. Our approach is demonstrated through the model consistency analysis of several mechanical designs, showing its validity, efficiency, and generality. Our method provides a systematic way to compare system-level and geometric-level designs, improving reliability and facilitating design translation. [ABSTRACT FROM AUTHOR]

Design processes can be decomposed into several steps, including information acquisition and application. Retrieving prior knowledge and experience is an important method of acquiring design information, thus designers' precedents retrieval styles reflect their design thinking. The obvious difference between industrial (ID) and mechanical design (MD) education is well known: ID education focuses on cultivating design thinking abilities, while MD education focuses on cultivating technical abilities. The background discipline influences design thinking methods. This study aims at exploring the similarities and differences between ID and MD students' precedents retrieval styles in the design process. Forty-eight junior and senior undergraduate students participated in a brainstorming experiment using the think-aloud method. Participants' prior knowledge and experience retrieved during brainstorming were coded and the frequency ratios were analyzed. We conclude that ID students are more inclined to extract and apply episodic precedents than MD students. Compared with semantic precedents, episodic precedents have a greater possibility for being applied to the final solution. [ABSTRACT FROM AUTHOR]

As computer-aided design (CAD) tools have become an essential aspect of modern mechanical engineering design, the demand for CAD experts has increased significantly. The development from novice, to proficient, to expert user is of particular interest to the industrial and academic design communities. Yet little is known about the development of modeling choices, strategies, and patterns that characterize expert CAD skills; much of the past work that reports user action data is based on student or novice data. We compared the CAD modeling process across nine proficient and ten expert designers as they were tested to complete the same design task. Under identical conditions-the same time constraints in the same CAD platform and with the same task-the expert users were able to complete a larger proportion of the task with higher dimensional accuracy. While the experts were able to dissect and retrieve geometries from manufacturing drawings more efficiently than proficient users, they were also able to plan a modeling strategy that required less effort and revisions. With our experimental findings, we identify the demand for procedural knowledge-building for young engineers, with the ultimate goal of more effectively developing experts in engineering design with CAD. [ABSTRACT FROM AUTHOR]

The process of opportunity recognition is pivotal to engineering design, fostering technological innovation and entrepreneurship. Although there are multiple studies conducted in the area of opportunity recognition studying the behaviors of entrepreneurs, examining engineering students' approaches have been underexplored. There is a lack of research in regards to opportunity recognition processes among engineering students, particularly in the context of design education. The presented study addresses this gap by qualitatively examining approaches to opportunity recognition among mechanical engineering students enrolled in an engineering design course. Using a sample of 23 mechanical engineering students, the approaches to opportunity recognition were analyzed using students' responses to open-ended survey questions and student group discussions. From the analysis of the qualitative data, four key themes emerged regarding the improvement of the device and process, user consideration, environmental sustainability, and information and resources accessed by students. The findings provide a deeper understanding that can be used to inform educational practices and further research in the area of opportunity recognition in engineering education settings. [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]

Hands-on engineering design is a critical element of quality engineering education commonly featured in the first and last year of undergraduate programs. Technical science and engineering coursework dominate the sophomore and junior year, often with fewer hands-on design experiences. We sought to mitigate this by integrating a hands-on engineering design project into a second-year thermodynamics-focused course for mechanical engineering students. We iterated on a heat-to-work device design project developed by Shepard and Hoxie to make it more open-ended, and to introduce a ‘who’ and a ‘why’ into the project by having students design devices to help hypothetical users accomplish tasks. We analyzed student reflections about the project using an inductive thematic approach. Our results indicate that the project was challenging; students consistently described experiencing failures. Most students were eventually able to succeed in the project using a combination of design iteration, risk-taking, and adaptation. They articulated growth in engineering design capabilities (including the valuation of simplicity in designs, brainstorming, applied learning, and time management), and increases in confidence (including takeaways about the importance of self-trust and intuition). In this paper, we present the revised project design and findings from its implementation using student and instructor reflections, and suggestions about how it could be implemented in thermodynamics courses for other mechanical engineering programs. [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]

[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]

• 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]