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Springs are fundamental components in mechanical systems, crucial for ensuring the safety and functionality of mechanisms. Timoshenko's stiffness formula accounts for both bending and torsional energy effects, providing accurate results for small deformations. However, when the deformation becomes large, the spring stiffness becomes a nonlinear problem due to the changing inclination angle and radius during deformation. In this study, we derive a formula for the cylindrical spring stiffness under nonlinear large deformation by considering two assumptions: the invariability of the polar angle at any point and spring wire length during deformation. This formula incorporates the effects of inclination and radius changes on the spring wire. We analyze the stiffness of the cylindrical spring with different initial inclinations using the finite element method (FEM). FEM results were compared with those obtained from Timoshenko's formula, Hiroyuki's formula, and the derived formula. For small deformations, the FEM results matched well with all three formulas. However, for nonlinear large deformations, the calculated results from Timoshenko's formula showed a discrepancy of up to 32.58% compared to the FEM results. The modified Hiroyuki formula also exhibited slightly poorer agreement with the FEM results than the formula proposed in this paper. On the other hand, our derived formula demonstrated excellent agreement with the FEM results for nonlinear large deformations. Therefore, our stiffness formula for cylindrical springs is recommended for mechanical engineering spring design applications involving nonlinear large deformations. [ABSTRACT FROM AUTHOR]

Earthquake-induced soil liquefaction is a catastrophic phenomenon that can damage existing building foundations and other structures, resulting in significant economic losses. Traditional mitigation techniques against liquefaction present critical aspects, such as high construction costs, impact on surrounding infrastructure and effects on the surrounding environment. Therefore, research is ongoing in order to develop new approaches and technologies suitable to mitigate liquefaction risk. Among the innovative countermeasures against liquefaction, Induced Partial Saturation (IPS) is considered one of the most promising technologies. It consists of introducing gas/air bubbles into the pore water of sandy soils in order to increase the compressibility of the fluid phase and then enhance liquefaction resistance. IPS is economical, eco-friendly and suitable for urbanised areas, where the need to reduce the risk of liquefaction must be addressed, taking into account the integrity of existing buildings. However, IPS is still far from being a routine technology since more aspects should be better understood. The main aim of this review is to raise some important questions and encourage further research and discussions on this topic. The review first analyses and discusses the effects of air/gas bubbles on the cyclic behaviour of sandy soils, focusing on the soil volume element scale and then extending the considerations to the real scale. The use of useful design charts is also described. Moreover, a section will be devoted to the effect of IPS under shallow foundations. The readers will fully understand the research trend of IPS liquefaction mitigation and will be encouraged to further explore new practical aspects to overcome the application difficulties and contribute to spreading the use of this technology. [ABSTRACT FROM AUTHOR]

This document is a summary of a special issue in the journal Applied Sciences titled "Feature Review Papers in Mechanical Engineering." The issue covers various topics in mechanical engineering, including crank-slide actuating mechanisms, industrial robots, cellular manufacturing systems, shape memory alloys, and the application of Constructal theory. The articles explore the advancements, challenges, and potential solutions in these areas, aiming to enhance efficiency, adaptability, sustainability, and control in mechanical systems. The research presented in this special issue offers valuable insights and directions for further study in the field of mechanical engineering. [Extracted from the article]

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]

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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]

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]

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]

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]

Background: Due to its counter-intuitive nature, understanding the dynamics of nonlinear systems has given rise to many challenges to overcome. This has brought about so many quests to answer because most engineering systems are ubiquitously nonlinear in nature. Vibration analysis is found to be one of the dominant and predictive maintenance techniques. It ranges from budding problems to catastrophic failure of the rotating machinery. It leads to acceptance testing, quality control, loose part detection, noise control, leak detection, machine design and engineering.For example, vibration analysis is found to be a significant approach in the industries for analyzing the performance of rotating machinery. Purpose: The study of vibrational resonance is important in many branches of engineering. For example, in mechanical and civil engineering design, vehicle design, the design of steam-turbine rotor-bearing systems, and bridge design, and the design of vibration controllers and isolators. Understanding vibrational resonance is important to ensure an appropriate running condition, increase the effiency of machines and a desired behavior of the systems. Method: In this work,vibrational resonance for a class of velocity-dependent potentials and nonpolynomial type oscillator is studied. By using the method of separation of motions (MSM) an analytical equation for the slow oscillations of the systems is obtained in terms of the parameter of the fast signal. The analytical computations are verified by fourth order Runge-Kutta method. Result: The analytical findings concure well with numerical studies. The response amplitude (Q) of the system depending on the amplitude of high-frequency drive forcing strength. The effects of damping and strength of nonlinearity on the emergence of vibrational resonances and resonant frequencies are analyzed. It is intresting to note that decreasing the strength of the nonlinearity significantly contributies to the emergence of VR in the lower values of amplitude of high-frequency drive forcing strength. When the damping term is increseaed the response amplitude (Q) is reduced. Conclusion: In this paper, we have proposed the new avenue in a broad class of velocity-dependent potential systems and nonpolynomial oscillators, which are typically found in physical and mechanical situations. The results are useful for the study of energy transfer phenomena for this class of nonlinear systems and for investigating the effects of damping on the nonlinear behaviour. These results are important for the design and fault diagnosis of mechanical systems and structures which can be described by this nonlinear model. As a result, the study of the dynamics of nonlinear systems has drawn the attention of researchers in various fields such as for instance, engineering and cognitive sciences. [ABSTRACT FROM AUTHOR]

In the era of the competitive environment, the improvement in current products is ensured through activities aimed at increasing a product’s quality level and, consequently, reducing the amount of waste. The dynamically changing production environment and sudden changes in customer expectations force us to take precise and well-thought-out development steps. Furthermore, it is important to anticipate favourable product changes to prepare for market changes over time. This is still an open problem. The aim of this study was to develop a method to predict the quality of potential product prototypes resulting from the proposed modifications of the product features. This methodology takes into account current customer expectations. The method was created based on the principles of creating Quality Function Deployment (QFD) in the context of taking into account current and future customer expectations regarding product features. This is a new approach to analysing product quality within the principles of the traditional QFD method. The originality of the study is the technique used in the method to estimate the expected values of product features and their importance (weights), taking into account current customer expectations. Its originality is also manifested in drawing conclusions supporting the decision-making process of product improvement, because it involves ensuring the pro-quality modification of selected features of current products in the order that is most advantageous from the customer’s point of view. The use of the proposed method allows for the analysis of the impact of modifying the current value of a product feature. The method is illustrated with an example of a vacuum cleaner for home use. However, the proposed method can be applied to the design of any product to predict products that will meet customer expectations.

With biped and quadruped robots becoming more prevalent in society, there is a strong push for universities to update their robotics curriculum to teach students how to design, build, and program legged robotic systems. One of the challenges associated with developing legged robotics curriculum is finding opportunities for students to engage in hands-on legged robotic activities that complement theory and enhance the overall learning process. This challenge is particularly evident at smaller universities or universities with limited research budgets where the cost of purchasing a quadruped platform can be prohibitive. With the recent release of several open-source quadruped robot designs, there is now an opportunity to incorporate quadruped platforms into more university classrooms. This paper outlines our approach to modifying one of these open-source designs to support our department's education, outreach, and research goals. The development of our modified, opensource quadruped platform (OpenMutt) was conducted under the auspices of a capstone mechanical engineering design project to demonstrate how the platform builds on existing curriculum and to identify areas where additional robotic instruction may be warranted. Our results indicate that it is possible to use capstone engineering design projects to identify and address potential gaps in existing curriculum. [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]

• 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]