A specific two-piece wheel is used for tyre/wheel assembly testing at the Aviation Tyres Science Centre, and the current research focuses on wheel optimisation. First, two load cases of the tyre/wheel assembly testing are introduced, including pure vertical force (extreme loading condition I) and combined vertical/lateral force (extreme loading condition II). FE analysis is performed using the intact wheel model, which provides von Mises stress and structural deflection under extreme loading conditions. Then, the intact wheel model is optimised using topology and shape optimisation methods. The topology optimisation aims to refine the wheel cross section. Subsequently, the shape optimisation is carried out by the combined global and local search. After the hybrid optimisation, the final wheel model squeezes 44.7% of the total material volume of the intact wheel model, while still fulfilling the strength requirements in terms of von Mises stress, structural deflection, and safety factor.

Innovating Mobility: A Student Competition in Wheel and Track Design

To address the challenge that existing transformable spoke wheel robots struggle to achieve balanced climbing performance in both forward and backward directions, a bidirectionally transformable and isotropic spoke wheel robot has been designed. The robot features a four-spoke wheel design, with each spoke wheel driven by two independent motors. The transformation of the spoke wheels is achieved through a combination of gear and linkage transmission. The symmetrical design of the transmission system ensures that the spoke wheels exhibit equivalent climbing capabilities and structural strength in both forward and backward directions, which is a property defined as isotropy. This design enables the robot to switch between hook-shaped and arc-shaped forms without altering its orientation, enhancing operational efficiency and reducing the risk of entrapment in scenarios where turning is restricted. This article presents a design methodology for the spoke wheel and evaluates the torque requirements for driving, along with the stair climbing capabilities. A prototype of the robot was developed, and various experiments were conducted on different terrains, including flat ground, steps, and stairs. The results demonstrate that the proposed design method for the transformable spoke wheel is practical, and robots utilizing this mechanism show great potential for real-world inspection tasks.

Abstract This paper proposes a lateral combined variable stiffness wheel system, aiming to resolve three key challenges in current wheel technologies: traditional pneumatic tires are susceptible to skidding and blowouts in complex terrains; it is difficult for conventional tires to balance lightweight design and structural durability; and existing non-pneumatic tires suffer from high maintenance costs. The design of this system is based on the concepts of modularity and adjustability. The main structure includes a main tire, three auxiliary units, and corresponding wheel hubs. Multi-level adjustment of wheel width is achieved by adding or removing auxiliary units, thereby modifying the wheel stiffness and improving the overall tire performance. In this study, finite element models of a combined non-pneumatic tire with different numbers of auxiliary units are established using Abaqus, and the load-bearing and grounding performances are analyzed. In addition, the fatigue performance of the wheel hub is investigated using FE-SAFE.The results show that when the number of auxiliary units increases to three, the tire stiffness increases significantly from 310 N/mm to 659 N/mm, representing an improvement of approximately 112.9%. Consequently, the contact area increases by 57.3%, the tire vertical deflection decreases by 52.9%, and the contact pressure distribution becomes more uniform. As a result, the overall load-bearing capacity, impact resistance, and traction performance of the tire are markedly enhanced. For wheel hubs of different sizes, the maximum stress under the specified radial load is 76.79 MPa, which is lower than the yield strength of 235 MPa, and the fatigue life reaches 1 million cycles at a stress amplitude of 0.2 MPa. While the overall wheel performance is improved, the proposed structure still satisfies the fatigue strength requirements of the wheel hub. Therefore, the lateral combined variable stiffness wheel system combines non-pneumatic tire safety and modular structural adaptability, which can effectively improve the passability and stability of the wheel in extreme terrain, reduce maintenance costs, and provide new ideas for wheel technology innovation.

The operational reliability of the elastic wheel, essential for specialized vehicle mobility on complex terrain, is critically constrained by fatigue failure under multi-axis ground loads. While high-fidelity physics-based simulation provides an accurate assessment, its “one-simulation-per-test” paradigm is inefficient for exploring multi-condition, multi-parameter designs. Conversely, purely data-driven methods are hindered by the scarcity of high-quality fatigue data. This paper proposes LightGBM-CH, an integrated framework that couples Discrete Element Method–Multi-Body Dynamics (DEM-MBD) simulation with an enhanced LightGBM model to overcome these limitations. The framework first converts high-fidelity simulations into a configurable data generator, producing batches of dynamic load–stress response data. A physics-informed feature engineering scheme then extracts 122 discriminative features characterizing six-dimensional loads, fatigue damage metrics, and load–stress coupling. To address the “small-sample, high-dimensional” challenge, a tailored training strategy incorporating robust scaling, correlation-based feature selection, and stability-constrained hyperparameter optimization is developed. Simulation experiments demonstrate that the LightGBM-CH model achieves a determination coefficient of 0.9251 and a root mean square error of 67.06, significantly outperforming benchmark models in accuracy and generalization. The study validates the framework’s engineering efficacy, identifies key influencing factors such as peak–stress ratio, and provides an intelligent, data-informed pathway for fatigue-resistant elastic wheel design.

This paper conducts a comprehensive comparison of the vibrational responses of elastic wheels and standard wheels under various excitation conditions. The investigation focuses on a frequency range spanning from 500 to 3750[Formula: see text]Hz, within which we observe that the radial modes of the elastic wheel tend to be relatively concentrated. This concentration can have significant implications for the performance and stability of the wheel during operation. One of the key findings of this study is that the mobility of the elastic wheel is notably higher than that of the standard wheel. This increased mobility is a double-edged sword; while it may enhance the wheel’s ability to adapt to varying loads and road conditions, it also predisposes the elastic wheel to higher levels of rim vibration. Such vibrations can lead to potential issues in terms of ride comfort. The frequency spectrum beyond 3750[Formula: see text]Hz, a marked difference in vibration levels between the two types of wheels becomes apparent. In this higher frequency range, the vibration levels experienced by the elastic wheel are several orders of magnitude lower than those of the standard wheel. This significant reduction in vibration can primarily be attributed to the unique properties of the rubber layer in the elastic wheel design. The rubber material acts as a crucial dampening agent, efficiently dissipating vibration energy that would otherwise contribute to increased noise and structural fatigue.

Understanding the self-assembly of multicomponent giant polyoxometalates and their subsequent controlled molecular growth is crucial for addressing the challenges of building multicomponent structural motifs and elucidating structure-property relationships in complex cluster chemistry, yet it presents a significant challenge. Herein, we report two unprecedented giant Mo wheels featuring unique multicomponent building blocks, which are a {Mo2VP2}-stabilized decamer {Mo110V10P20} and a {Mo2VP2}-mediated elliptical tetradecamer {Mo154V4P8}. The former constitutes the long-sought archetypal decameric prototype, while the latter gives rise to a rare giant structural variant alongside classical {Mo154}. Furthermore, employing anion-guided strategies enabled in situ site-specific molecular growth at {Mo2} active sites of these wheels: sulfate-induced symmetrical capping of {Mo110V10P20} with two {Mo11} units yields Mo green {Mo132V10P20} whereas a hierarchical growth mediated by PhPO32-/SO42- anions on {Mo154V4P8} generates Mo blue {Mo188V11P20} through the incorporation of {Mo1}, arch-shaped {Mo4}, and {ε-MoV24VV7} guests. Molecular-growth products exhibit enhanced broad-spectrum light absorption and improved charge separation efficiency, leading to superior photocatalytic aerobic oxidation performance over both their precursors and undoped analogues. This study pioneers the use of multicomponent moieties in the design of giant Mo wheels and establishes an anion-guided strategy for precisely regulating molecular growth, which opens pathways to functional giant clusters with tailored properties.

This study presents a comprehensive approach for measuring wheel-rail contact stress and its distribution. To address the limitations of existing measurement methods, the research integrates direct and indirect measurement techniques. A novel thin-film pressure sensor with an inclined test area arrangement is designed for the direct stress measurement under low-load conditions. By introducing a correction function from direct measurement results under low loads, an indirect measurement is developed, thereby resolving the error issues inherent in the traditional indirect methods when measuring edge stress states. The accuracy of edge contact stress measurement has been significantly enhanced. A single-wheel contact test apparatus was developed to validate the effectiveness and applicability of the proposed method under varying loads and wheel diameters, with comparative verification conducted through finite element simulations. The results demonstrate that the proposed method can effectively measure both the edge stress in the wheel-rail contact and the stress distribution across the entire contact area, providing a reliable theoretical foundation for the structural design of wheels and rails.

Participatory Design is one of the traditional human-centred approaches commonly used during the early stages of the design process. Currently, Large Language Models and Generative Artificial Intelligence (GenAI) are increasingly being adopted in the early stage of design, particularly for requirements analysis and conceptual design. To harness the respective strengths of Participatory Design and GenAI, it is essential to approach the problem through the lens of multimodal human–machine perception. In this paper, we propose a new multimodal GenAI-Driven Participatory Design approach and develop the Multi-PDAI platform, which is validated in the context of wheeled humanoid robot design. A crossover experiment (N designers = 8, N users = 16) was conducted with evaluation data on the generated images from design industry experts (N = 10). Platform usability was assessed using the SUS scale. In addition, users’ UEQ data and designers’ IMI data were analyzed, with systematic comparisons of initial and final prompt templates, design completion criteria, and time–process metrics. The results show that the images generated by the Multi-PDAI platform are more innovative and aesthetically appealing, and the platform demonstrates better usability compared to Stable Diffusion (M = 72.5, Sig. = 0.043). These findings further support the hypothesis that participatory design and GenAI are mutually beneficial, and that multimodality in GenAI is essential.

Abstract To investigate the improvement of surface textured on the noise and vibration characteristics of the tensioner wheels in a belt drive system, this study, for the first time, combines acoustic array noise source identification with laser Doppler vibrometry technology. This enables synchronous and precise measurement and correlation analysis of the noise and vibration generated by the textured tensioner wheels during operation. Experimental results indicate that the tension pulley-back of belt interaction is the primary noise source of the system, and its noise level increases significantly with the relative sliding speed: at 3.4 m/s, the sound pressure level reaches 94 dB, which is 44.3% higher than that at 0.34 m/s. Quantitative analysis confirms that surface textured effectively suppresses vibration, reducing the average absolute amplitude of vibration acceleration by 17.1% to 20.5% within the speed range of 0.34–3.4 m/s. Frequency domain analysis further reveals the underlying mechanism: the textured significantly suppresses high-frequency vibration energy in the 2000–5000 Hz range, but has limited impact on low-frequency vibrations near the system's natural frequency. This study demonstrates that the combined measurement method based on acoustic array and laser Doppler vibrometry can effectively diagnose vibration and noise in belt drive systems. Furthermore, the surface textured design of the tensioner wheels provides an effective solution for controlling vibration and noise in belt drive systems.

Omnidirectional mobile platforms, known for their exceptional maneuverability in confined spaces, often encounter not only energy efficiency challenges due to the design of roller-bearing wheels but also operational limitations in real-world environments such as height differences and uneven terrain. To overcome these limitations, it is necessary to enable switching between omnidirectional and conventional driving modes through adaptive motion mode switching. This approach combines the maneuverability required for navigation in tight spaces with improved off-road capability and energy efficiency on uneven surfaces and slopes. This study proposes an algorithm for adaptive motion mode switching, providing transitions from an omnidirectional to a classical kinematic scheme and back via a specially developed compact switching mechanism. To achieve this, enhanced kinematic, dynamic, and energy models were utilized in combination with laboratory experiments conducted on a reconfigurable platform. The proposed improvements make it possible to perform a simple and rapid transition between kinematic configurations using the compact switching mechanism. Experimental studies were carried out under laboratory conditions on a flat concrete surface where the robot followed a closed trajectory. During the experiments, energy consumption and trajectory-tracking errors were recorded for holonomic, nonholonomic, and reconfigurable motion modes. Comparative analysis demonstrated that the proposed switching algorithm reduces energy consumption by an average of 8 % while maintaining maneuverability. For larger robots whose total mass significantly exceeds that of the reconfiguration mechanism energy savings in real-world scenarios can be even greater due to the system ability to optimize energy usage and select the most efficient configuration for different trajectory segments. The system retains high maneuverability and ensures efficient navigation in complex environments. The presented algorithm enables the platform to achieve a crucial balance between mobility, efficiency, and control accuracy. This opens the possibility for the practical implementation of reconfigurable robots in real-world service applications. The obtained results have practical significance for the design of adaptive mechanical and control systems that enhance the operational flexibility of mobile platforms under resource-constrained conditions.

Abstract Automotive manufacturers continuously seek to improve vehicle performance by developing components that are safe, fuel efficient, and lightweight. Reducing the unsprung weight, particularly through wheel optimization, is a key focus area due to its direct impact on vehicle dynamics and efficiency. The wheel, a critical component of the suspension system, must withstand both static and dynamic loads while maintaining structural integrity. This study aims to analyze the stress distribution in an aluminum alloy wheel, identify discrepancies between experimental and numerical results, and develop a methodology to improve the correlation between experimental stress analysis (ESA) and finite element analysis (FEA). Ultimately, the goal is to use this improved correlation to optimize wheel design in terms of fatigue life and structural strength. ESA was conducted on a standard aluminum alloy wheel using a developed test bench to simulate loading condition as per the standards. The same setup was modeled using FEA to identify stress distribution and critical regions. Discrepancies between ESA and FEA were investigated through material characterization and refinement of the experimental test setup. A methodology was proposed to enhance the accuracy and consistency of the correlation between ESA and FEA results. Fatigue tests were subsequently conducted on the wheels to validate the analytical predictions. The proposed methodology effectively minimized the deviation between ESA and FEA results to within 3%–6%, ensuring higher reliability in stress prediction. The enhanced correlation enabled an optimized wheel design, achieving a 7.82% reduction in excess material while maintaining structural integrity, safety, and performance standards. Comparative analysis between the baseline and optimized wheel designs showed enhancements in fatigue life and structural strength. Overall, the proposed approach not only strengthens the correlation between experimental and numerical analyses but also enables the design of lighter and stronger alloy wheels that comply with automotive performance and safety requirements.

The work focuses on building a sophisticated legged-wheel model that will perform in different terrains for convenient locomotion. Although a variation of wheels is available for different vehicles, locomotion mechanisms, or robotics, there is still a lack of convenient transformable wheels for even and uneven environments. When focusing on wheelchairs, the main obstacle is seen in stairs. Hence, the focus of this work is to model and analyze a transformable wheel for a wheelchair. Several parameters will be examined to find the most optimal solutions. This work carried out 41 simulations to assess performance under various conditions, taking into account factors like leg length, number of legs, acting force, and rotor speed. It was found that, with the given environment, the following parameters were most optimal for the wheelchair to move on stairs and on even terrain. The wheels with a length of 19 cm showed the best results for climbing stairs. A further increase in length would introduce instability. The optimal rotation speed was found to be around 20-22 rpm. At higher speed, it led to excessive resistance and instability. It was also found that a person's weight acting on the wheelchair is significant, as lighter weight results in slipping and incapability of climbing stairs. In concluding the findings, it is obvious that each parameter plays a vital role in the overall performance of the wheelchair.

With the increasing complexity of industrial products, the requirements for environmental protection, and resource conservation, new manufacturing technologies have become necessary. 3D printing or additive manufacturing (AM) can be used to create parts by adding material layer by layer. The analysis of the data obtained by applying finite element method (FEM) on gears produced from polylactic acid (PLA), thermic treated PLA and Acrylonitrile Butadiene Styrene (ABS) shows the equivalent stress values obtained numerically in comparison with those obtained experimentally through tensile testing. Thus, there is a positive percentage difference between tensile strength σeq,max for PLA material of 18.32%, for ABS material of 15.98%, and for treated PLA material of 18.39%. Thus, the contact stresses identified by the numerical method in the contact area of the gear teeth flanks were compared with the average compressive stresses obtained experimentally for specimens made from PLA, ABS, and treated PLA materials, printed with a 100% infill percentage. There is a percentage difference between these values of 64.4% for PLA material, 63.18% for ABS material, and 48.21% for treated PLA material. This indicates that the gears made from the considered materials can operate without issues if no other loads are applied. The integration of numerical simulation results with experimental data validates the accuracy of the analysis methods, providing a solid basis for decision-making in the design and improvement of gear wheels.

Design and synthesis of a 24-membered macrocyclic wheel (MC) based [2]rotaxane (ROT) with multiple functional groups are reported. Threading followed by capping strategy was used to form a mechanically interlocked structure. Initially, metal ion template [2]pseudorotaxane was formed via ternary complexations. Then, stoppering via click chemistry results [2]rotaxane. The interlocking nature was established by ESI-MS spectrometry and various 1D, 2D NMR studies. This concept also offers a valuable pedagogical framework for teaching and learning modern chemical design strategies and, the interpretation of various spectroscopic, and spectrometric data, extensive use of chem-draw software for undergraduate students. This article explores the design, synthesis and characterization of pseudorotaxane and rotaxane, importance of interlocked systems in the pedagogy at undergraduate level with the aim to deep understanding of modular synthesis and orthogonal reactivity.

Weight reduction in vehicles remains a central priority in the automotive industry, as it directly affects fuel economy and emissions. Wheel rims, being among the unsprung components, offer considerable scope for lightweighting through material and design optimization. This research evaluates the replacement of conventional aluminium alloy rims with advanced composite materials, aiming to minimize mass without compromising structural strength and durability. A comprehensive Finite Element Analysis (FEA) framework is employed to compare the baseline aluminium alloy rim with an optimized composite design. The investigation encompasses stress distribution, deformation characteristics, and modal response under representative static and dynamic loading conditions. The results reveal that composite rims can achieve notable reductions in weight while sustaining the required structural performance. While the optimized carbon fiber composite rim demonstrates significant mass reduction compared to the baseline aluminium alloy, it exhibits a modest increase in maximum deformation under peak loading conditions. Preliminary cost analysis indicates higher material and manufacturing expenses, highlighting a trade-off between performance gains and economic considerations. These findings demonstrate the potential of composite materials to enhance vehicle efficiency and support the broader goals of sustainable and energy-efficient automotive engineering.

An incinerator is a high-temperature waste-burning device with a closed, insulated combustion chamber, designed to minimize environmental impact [1]. Modern incinerators aim to reduce inorganic waste and smoke emissions, particularly in Metro City, Lampung Province [2]. A key component is the wheel, which reduces friction and enhances mobility [3]. This study focuses on designing the incinerator wheel, determining its geometry and material, and analyzing stress, strain, and deformation through simulation [4]. The design process used Autodesk Inventor Professional, while simulations were performed in SolidWorks [5]. Tests were conducted under three load conditions: no load, 250 kg, and 500 kg. The final wheel design measures 150 mm in diameter, 50 mm in width, and 10 mm in thickness, using cast iron. Simulation results show stress, strain, and deformation remain below material limits, even at 500 kg load, confirming the wheel’s safety and reliability for optimal incinerator performance.

Introduction In rescue mission scenarios, special vehicles need to frequently navigate through complex terrains such as muddy wilderness and rugged mountains, which poses challenges to their mobility, obstacle-crossing capabilities. However, the existing wheeled special vehicles have a poor passing ability, while the tracked special vehicles have a poor maneuverability. Neither of them can meet the requirements in complex rescue scenarios. Methods To solve the problem, this work proposes a scheme of wheel-track composite variant wheels, and analyzes the switching principle between the wheels and tracks. Using mechanical principles and geometric methods, an in-depth theoretical analysis of the passing ability is carried out, and the main structural parameters are designed. By means of the finite element method, transient and static analyses are carried out. According to the analysis results, the key parts with the greatest stress and deformation are precisely located, and the stress singular points are dissected to provide a clear direction for optimization. Based on the analysis results, the structural parameters are optimized by using the response surface methodology, such that both the stress and deformation meet the requirements of strength and stiffness. Finally, a prototype is fabricated based on the optimized results and field tests are conducted. Results The test results show that the variant wheel optimized is significantly superior to the traditional wheel in terms of the maximum height of climbing step and maximum grade-ability. In terms of the maximum speed, it far exceeds the tracked structure. Discussion The research provides theoretical support and practical guidance for comprehensively enhancing the maneuverability and passing ability of special vehicles.

Three-piece alloy wheels are widely used across the automotive industry, favoured due to their lightweight construction and ease of customisation. Vehicle wheels must withstand forces generated during acceleration, braking, cornering, and impacts, ensuring safety and durability under real-world conditions. Finite element analysis (FEA) plays a crucial role in simulating these loading conditions, thoroughly assessing structural performance prior to manufacturing. This study develops and validates a digital FEA testing framework tailored to low-volume wheel manufacturers, demonstrating that FEA can replace traditional physical wheel fatigue tests where such facilities are unavailable. This research was conducted in collaboration with a UK company specialising in the design and manufacture of bespoke, limited-production three-piece alloy wheels. However, the absence of dedicated structural testing procedures caused many of their existing designs to be overengineered, resulting in excessive material usage, increased weight, and high production costs. In some cases, lack of testing also contributed to wheel failures. This work selected three of the company’s existing wheel designs and subjected them to comprehensive analysis. Using FEA, each wheel was evaluated under industry-standard radial, cornering, biaxial, and impact tests. To verify the simulations, a known case of wheel failure was analysed and compared to real-world values. Once verified, any design issues were addressed. The redesigned wheels achieved substantial weight reduction (up to 25%), while still meeting or exceeding the relevant safety standards and allowing for manufacturability. Ultimately, this work demonstrated that applying digital simulation techniques can significantly improve the performance and safety of custom three-piece alloy wheels.

The rising demand for dual-operation vehicles capable of seamless transitions between urban tramways and heavy rail networks has intensified global interest in tram-train systems. These systems offer improved operational efficiency, reduced infrastructure costs, and enhanced passenger convenience. However, geometric disparities across rail types present a critical technical challenge. This study addresses the issue through an optimized wheel design compatible with six distinct rail configurations. A baseline wheel profile is proposed, incorporating a specialized geometry and unique rim structure to support smooth transitions at crossings and turnouts. A validated multi-physics simulation model is developed to assess dynamic performance across ten representative rail combinations. Derailment risk and wear number are defined as key quantities of interest (QoIs) and analyzed across three rail categories. Six geometric parameters, selected from a practical design perspective, are evaluated, with three screened out via the Morris sensitivity method. Based on algorithmic benchmarking, the Elliptical Basis Function (EBF) is selected to construct a surrogate model. The resulting meta-model captures multidimensional sensitivities and supports iterative optimization to yield optimal wheel profiles for each QoI. Beyond simulation—including dynamic response and cumulative wear prediction—full-scale experiments are performed on a newly constructed tram-train testbed featuring a dedicated transition lane. The optimized designs demonstrate superior dynamic stability, reduced wear, and decreased derailment risk, with good agreement between numerical and experimental results. This study contributes to the advancement of hybrid rail transit by integrating surrogate-based optimization with comprehensive computational and experimental validation, laying a foundation for safer, more efficient tram-train operations.