Search Results (2,051)

This work is part of a research project aimed at producing ceramic-like materials, without the need for an initial sintering, for potential applications in catalysis or filtration at temperatures up to 1000 °C. In that context, cordierite-derived materials were prepared from recycled cordierite powder (automotive industry waste) bonded with metakaolin-potassium silicate geopolymer. The principle is that these materials, prepared at temperatures below 100 °C, acquire their final properties during the high-temperature commissioning. The focus is on the influence of the K/Al ratio and cordierite fraction on the stability of the dimensions and porosity during heating at 1000 °C, and on the final Young’s modulus and coefficient of thermal expansion. Conventional and high-temperature XRD evidenced the absence of crystallization of the geopolymer binder and interaction with the cordierite filler during the heating stage when K/Al = 1 or 0.75. By contrast, crystallization of kalsilite and leucite, and diffusion of potassium ions in the structure of cordierite is evidenced for K/Al = 1.5 and 2.3. These differences strongly influence the shrinkage due to sintering and the final properties. It is shown that a K/Al ratio of 0.75 or 1 is favorable to the stability of the porosity, around 25 to 30%. Moreover, a low coefficient of thermal expansion of 4 to 4.5 10⁻⁶ K⁻¹ and a Young’s modulus of 40 to 45 GPa is obtained. Full article

This study explores the automation enhancement in the assembly process of wiring harnesses for automotive applications, focusing on manually inserting fuses and relays into boxes—a task known for quality and efficiency challenges. This research aimed to address these challenges by implementing a robotic arm integrated with API technology for digital twin. The methods used included the development of a digital twin model to simulate and monitor the assembly process, supported by real-time adjustments and optimizations. The results showed that the robotic system significantly improved the accuracy and speed of fuse insertion, reducing the insertion errors typically seen in manual operations. The conclusions drawn from the research confirm the feasibility of using robotic automation supported by digital twin technology to enhance assembly processes in automotive manufacturing, promising substantial improvements in production efficiency and quality control. Full article

Over the past few years, researchers have developed the alloy Al-Mg-Zn(-Cu), a new aluminum alloy based on the technique of ‘crossover alloying’. The main strengthening phase of this novel alloy is T-Mg₃₂(Al, X)₄₉(X is Zn and Cu) after ageing and hardening. This alloy system has exceptional strength and corrosion resistance, making it a promising candidate for applications in fields like automotive, marine, aerospace, and many others. In this work, the research progress of the Al-Mg-Zn(-Cu) alloy based on microstructure control, composition, design, and properties has been reviewed. Future directions for the research of this alloy are highlighted, too. In this work, crossover alloys are presented as a potential novel class of Al alloys implicating a pioneering design approach, with particular emphasis on the aeronautical and aerospace field in which radiation resistance results are one hundred times higher than traditional precipitation hardening alloys. Full article

The automotive industry is one of the most demanding sectors of all manufacturing industries due to its competitiveness. It is necessary to innovate through the implementation of automated and robotic equipment, leading to cycle time and labor cost reduction. This work aims to design semi-automatic equipment to assemble cabling connectors used in the automotive sector, replacing a manual process currently taking place in an automotive components company. In the proposed equipment, the operator places a connector in the equipment, and the components (pins and seals) are automatically inserted. A vision sensor with artificial intelligence then confirms the correct application. The equipment operation defined as Finite Element Method (FEM) was applied for structural verification; the materials and fabrication processes were detailed; the associated costs were calculated, and the equipment subsets were validated. The design was successfully accomplished, and the imposed requirements were fulfilled, with significant advantages over the current process, providing new knowledge on how semi-automatic systems can be deployed to enhance the productivity and quality of manufacturing processes. The design principles and insights gained from this work can be applied to other automation challenges, particularly where manual processes need to be replaced by more efficient semi-automatic or automatic systems. The modularity of the overall solution and the design concepts of the component inserter, component feeder, and assembly process allow for its use in different assembly scenarios beyond the automotive sector, such as electronics or aerospace, providing a contribution to increased competitiveness and survival in the global market. Full article

As vehicle body structures become stronger and part designs more complex for lightweight, controlling frictional properties in automotive press forming has gained critical importance. Friction, a key factor in formability, is influenced by variables such as contact pressure, sliding velocity, sheet strength, and coatings. This study investigates the friction characteristics of steels with tensile strengths of 340 MPa and 980 MPa, under galvanized (GI) and galvannealed (GA) zinc coatings. Experimental results reveal that asperity flattening, a significant factor in determining friction, increases with contact pressure normalized by tensile strength, particularly for GI-coated steels. However, the relationship between friction and surface flattening deviates from conventional expectations, with the friction coefficient initially rising with increased flattening area up to ~20% before decreasing as flattening progresses. These findings suggest that traditional empirical formulas may not fully capture friction behavior under specific conditions. By understanding this inflection point, where friction reduces under high contact pressure, the study provides valuable insights for optimizing formability and improving sheet metal forming processes, especially in scenarios where precise friction control is critical for producing high-quality automotive parts. Full article

Water in the engine/combustion chamber is not a novel phenomenon. Even humidity has a major effect on internal combustion engine emissions and can thus be considered the first invisibly present emission technology. With modern techniques, the problematic aspects of water, such as corrosion and lubrication issues, seem to disappear, and the benefits of water’s effect in combustion may also be enhanced in the context of EURO 7. The current study examines the literature on the effects of water on diesel combustion in chronological sequence, focusing on changes over the last three decades. Then it analyzes and re-evaluates the water effect in the current technology and the forthcoming Euro 7 regulatory context, comparing the conclusions with current automotive applications and mobility trends, in order to show the possible benefits and prospective research avenues in this sector. Techniques introducing water to combustion could be a major approach in terms of the EURO 7 retrofit mandate, as well as a feasible technique for concurrent nitrogen oxides and particulate reduction. Full article

Al-Si alloys are vital in the aerospace and automotive industries due to their high strength-to-weight ratio, excellent ductility, and superior corrosion resistance. These properties, along with good thermal conductivity, low thermal expansion, and enhanced wear resistance due to silicon, make them ideal for lightweight, high-performance components like engine parts exposed to harsh conditions and thermal cycling. In recent years, the development of aluminium metal matrix composites using Al-Si alloys as the base material has gathered significant attention. These composites are engineered by integrating various reinforcing particles into the aluminium matrix, which results in remarkable improvements in the wear resistance, hardness, and overall mechanical performance of the material. The stir casting process, a well-established and cost-effective method, is frequently employed to ensure a uniform distribution of these reinforcing particles within the matrix. This review delves into the influence of different types of reinforcing particles on the properties of Al-Si alloy-based AMCs. The incorporation of these reinforcements has been shown to significantly enhance wear resistance, reduce friction, and improve the overall strength and toughness of the composites, making them ideal candidates for high-performance applications in the automotive and aerospace sectors. Moreover, this review highlights the challenges associated with the fabrication of these composites, such as achieving a homogeneous particle distribution and minimizing porosity. It also discusses the latest advancements in processing techniques aimed at overcoming these challenges. Additionally, this review addresses the potential environmental and economic benefits of using natural reinforcements, which not only reduce material costs but also contribute to sustainable manufacturing practices. Full article

In recent years, there has been a significant increase in research on hydrogen due to the urgent need to move away from carbon-intensive energy sources. This transition highlights the critical role of hydrogen storage technology, where hydrogen tanks are crucial for achieving cleaner energy solutions. This paper aims to provide a general overview of hydrogen treatment from a mechanical viewpoint, and to create a comprehensive review that integrates the concepts of hydrogen safety and storage. This study explores the potential of hydrogen applications as a clean energy alternative and their role in various sectors, including industry, automotive, aerospace, and marine fields. The review also discusses design technologies, safety measures, material improvements, social impacts, and the regulatory landscape of hydrogen storage tanks and safety technology. This work provides a historical literature review up to 2014 and a systematic literature review from 2014 to the present to fill the gap between hydrogen storage and safety. In particular, a fundamental feature of this work is leveraging systematic procedural techniques for performing an unbiased review study to offer a detailed analysis of contemporary advancements. This innovative approach differs significantly from conventional review methods, since it involves a replicable, scientific, and transparent process, which culminates in minimizing bias and allows for highlighting the fundamental issues about the topics of interest and the main conclusions of the experts in the field of reference. The systematic approach employed in the paper was used to analyze 55 scientific articles, resulting in the identification of six primary categories. The key findings of this review work underline the need for improved materials, enhanced safety protocols, and robust infrastructure to support hydrogen adoption. More importantly, one of the fundamental results of the present review analysis is pinpointing the central role that composite materials will play during the transition toward hydrogen applications based on thin-walled industrial vessels. Future research directions are also proposed in the paper, thereby emphasizing the importance of interdisciplinary collaboration to overcome existing challenges and facilitate the safe and efficient use of hydrogen. Full article

The automotive industry is increasingly focused on developing more energy-efficient and eco-friendly air-conditioning systems. In this context, CO₂ microchannel gas coolers (MCGCs) have emerged as promising alternatives due to their low global warming potential (GWP) and environmental benefits. This paper explores the application of machine learning (ML) algorithms to predict the thermohydraulic performance of MCGCs in automotive air-conditioning systems. Using data generated from an experimentally validated numerical model, this study compares various ML techniques, including both linear and nonlinear regression models, to forecast key performance metrics such as refrigerant outlet temperature, pressure drop, and heat transfer rate. Spearman’s correlation was employed to develop performance maps, whereas the R² and MSE metrics were used to evaluate the models’ predictive accuracy. The linear models gave around 70% forecasting accuracy for pressure drop across the gas cooler and 97% accuracy for refrigerant outlet temperature, whereas the nonlinear models achieved more accurate predictions, with an accuracy ranging from 71% to 99%. This implies that nonlinear regression generally performs better than linear regression models in assessing the overall thermohydraulic performance of microchannel gas coolers. This research brings forth new ideas on how ML methods can be applied to enhance efficiency and effectiveness in gas coolers, contributing to the development of more eco-friendly automotive air-conditioning systems. Full article

Thin sound-absorbing materials are particularly desired in space-constrained applications, such as in the automotive industry. In this study, we theoretically analyzed the structure of relatively thin glass wool or polyester wool laminated with a nonpermeable polyethylene membrane and a permeable nonwoven fabric sheet. We also measured and compared the sound-absorption coefficients of these samples between experimental and theoretical values. The sound-absorption coefficient was derived using the transfer matrix method. The Rayleigh model was applied to describe the acoustic behavior of glass wool and nonwoven sheet, while the Miki model was used for polyester wool. Mathematical formulas were employed to model an air layer without damping and a vibrating membrane. These acoustic components were integrated into a transfer matrix framework to calculate the sound-absorption coefficient. The sound-absorption coefficients of glass wool and polyester wool were progressively enhanced by sequentially adding suitable nonwoven fabric and PE membranes. A sample approximately 10 mm thick, featuring permeable and nonpermeable membranes as outer layers of porous sound-absorbing material, achieved a sound-absorption coefficient equivalent to that of a sample occupying 20 mm thickness (10 mm of porous sound-absorbing material with a 10 mm back air layer). Full article

Fatigue crack propagation is a critical phenomenon that affects the structural integrity and lifetime of various engineering components. Over the years, finite element modeling (FEM) has emerged as a powerful tool for studying fatigue crack propagation and predicting crack growth behavior. This study offers a thorough overview of recent advancements in finite element modeling (FEM) of fatigue crack propagation. It highlights cutting-edge techniques, methodologies, and developments, focusing on their strengths and limitations. Key topics include crack initiation and propagation modeling, the fundamentals of finite element modeling, and advanced techniques specifically for fatigue crack propagation. This study discusses the latest developments in FEM, including the Extended Finite Element Method, Cohesive Zone Modeling, Virtual Crack Closure Technique, Adaptive Mesh Refinement, Dual Boundary Element Method, Phase Field Modeling, Multi-Scale Modeling, Probabilistic Approaches, and Moving Mesh Techniques. Challenges in FEM are also addressed, such as computational complexity, material characterization, meshing issues, and model validation. Additionally, the article underscores the successful application of FEM in various industries, including aerospace, automotive, civil engineering, and biomechanics. Full article

This paper focuses on key engineering issues, particularly the overall turbulent transport of paint spray and coating film distribution characteristics, in the process of airless spraying film formation. By deeply considering the geometric features of spherical surfaces and their impact on the near-wall region of the flow field, an airless spraying film formation model consisting of the Eulerian multiphase model, the realizable k–ε turbulence model, and the Eulerian Wall Film model was established. Through numerical simulations of static spraying on the inner and outer walls of spherical surfaces with different radii, the influence of geometric features on the spray flow field and film formation characteristics on spherical surfaces was investigated. Subsequently, based on numerical simulations of dynamic spraying on different nozzle trajectories, the film formation characteristics were analyzed, and the optimal spray trajectory planning method was determined. Additionally, this study examined the coating distribution characteristics during dynamic spraying on spherical surfaces with varying geometric dimensions. Finally, a kind of chlorinated rubber anti-corrosion primer was chosen to carry out spraying experiments, which validated that the airless spray coating model and the corresponding numerical simulation methods established in this paper were reasonable and feasible for investigating the film formation characteristics on spherical surfaces. This work is expected to further promote the application of airless spray techniques in machinery, automotive, shipbuilding, and aviation industries. Full article

Aramid copolymers have garnered significant interest due to their potential applications in extreme environments such as the aerospace, defense, and automotive industries. Recent developments in aramid copolymers have moved beyond their traditional use in high-strength, high-temperature resistant fibers. There is now a demand for new polymers that can easily be processed into thin films for applications such as electrical insulation films and membranes, utilizing the inherent properties of aramid copolymers. In this work, we demonstrate two novel aramid copolymers that are capable of polymerizing in polar organic solvents with a high degree of polymerization, achieved by incorporating flexible bis(4-aminophenoxy) benzene moieties into the chain backbone. The synthesized MBAB-aramid and PBAB-aramid have enabled the fabrication of exceptionally thin, clear films, with an average molecular weight exceeding 150 kDa and a thickness ranging from 3 to 10 μm. The dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) reveal that the thin films of MBAB-aramid and PBAB-aramid exhibited glass transition temperatures of 270.1 °C and 292.7 °C, respectively, and thermal decomposition temperatures of 449.6 °C and 465.5 °C, respectively. The mechanical tensile analysis of the 5 μm thick films confirmed that the tensile strengths, with elongation at break, are 107.1 MPa (50.7%) for MBAB-aramid and 113.5 MPa (58.4%) for PBAB-aramid, respectively. The thermal and mechanical properties consistently differ between the two polymers, which is attributed to variations in the linearity of the polymer structures and the resulting differences in the density of intermolecular hydrogen bonding and pi-pi interactions. The resulting high-strength, ultra-thin aramid materials offer numerous potential applications in thin films, membranes, and functional coatings across various industries. Full article

This paper contains the results of numerical investigations into two cooling system types for cells of three types. The galvanic cell geometries which were considered were pouches, cylinders and prisms. By design, the cooling system for a vehicle is specialised to prevent an uncontrolled temperature increase at higher discharge rates. Consideration was given to the question of which cooling method would be sufficient to reduce the temperature rise of battery cells. The first cooling method investigated is one that uses direct contact with the air flow to cool the cells, a method that is very commonly used in automotive engineering, as it is less complicated. This study employs a method that uses a fan to induce forced convection, increasing the airflow over cells housed within a thermoplastic composite container. Another method, fluid cooling, is notable for its greater efficiency due to the use of a non-conducting coolant, which has also better energy absorption properties. In this study, immersion cooling was employed, utilising oil circulation through cells contained within a thermoplastic composite container, which was facilitated by a pump system. This publication shows the influence of the cell’s geometry and the type of cooling system on the temperature rise of cells when they are discharging at the appropriate power rate. The results of this study highlight the differences in cooling performance between the two methods, providing a clear basis for selecting the most suitable solution for specific applications. Full article

Human–machine interaction (HMI) is becoming increasingly important, especially in the automotive industry, where advancements in automated driving and driver assistance systems are key to enhancing driver safety and convenience. Among the many HMI interfaces, tactile sensing has been widely used in automotive applications as it enables instant and direct interactions with drivers. An area that remains underexplored among the tactile HMI interfaces is the application of haptic feedback to gear shifter modules. Therefore, this study investigates the design optimization of a dial gear shifter by analyzing the vibrations transmitted to the knob surface from an integrated haptic actuator. Specifically, we first tuned the mechanical properties of the haptic actuator (in terms of the resonance frequency and vibration level) in a simulation model by referring to experimental results. Next, a numerical model of a dial gear shifter was constructed, integrated with a haptic actuator, and tuned with the experimental results. The model was further optimized based on the design of the experiment and sensitivity analyses. The optimized design yielded a 24.5% improvement in the vibration level compared with the reference design, exceeding the minimum threshold (>~2.5 m/s² at 200 Hz) required for tactile sensing. The vibration enhancement (>22.x%) was also confirmed under the simulated hand-grabbing condition. This study is technically significant as it demonstrates that the haptic vibration in a dial gear shifter can be efficiently optimized through numerical analyses. This research will be used for the actual prototyping of a dial gear shifter to provide a safe driving experience for drivers. Full article