搜索结果：Automotive

The hole expansion ratio (HER) is a critical formability metric for advanced high-strength steels (AHSS) in automotive applications; however, its experimental determination is costly and time-consuming. This study presents a machine learning framework for HER prediction using physics-informed synthetic data generation to address data scarcity challenges. A dataset of 300 AHSS conditions was generated based on validated empirical relationships from the literature, incorporating chemical composition, microstructure fractions, and mechanical properties. Multiple machine learning algorithms were evaluated, with the optimized Gradient Boosting model achieving excellent predictive performance on an independent test set (R2 = 0.80, RMSE = 5.81%, MAE = 4.93%). The feature importance analysis revealed physically meaningful rankings, with the ultimate tensile strength dominating (40.9%), followed by the bainite volume fraction (15.1%), martensite volume fraction (14.7%), and strain hardening exponent (12.4%). These rankings align with the established metallurgical understanding, thereby validating our synthetic data approach. The results demonstrate that machine learning models trained on physics-informed synthetic data can accurately predict the HER values with errors comparable to the experimental variability, providing a practical tool for accelerated AHSS design and optimization in automotive applications.

Motor vehicle accidents remain a leading cause of craniofacial trauma, with injury severity evolving alongside automotive safety advancements. While airbags and seatbelts have revolutionized trauma prevention, reducing worldwide mortality by over 70,000 lives in five years, their mechanics can paradoxically modify or exacerbate facial injuries due to occupant positioning, chemical factors, and collision dynamics. This study examines injury patterns, mechanisms, and trauma prevention strategies related to airbag-related maxillofacial trauma. A scoping review was conducted across PubMed, Google Scholar, and Scopus (up to October 2025). Search terms included "airbag," "maxillofacial injuries," and "occupant restraint system injuries." Inclusion criteria focused on human studies reporting airbag-related facial trauma. Two reviewers independently screened literature, resolving discrepancies via consensus. Orbital fractures (particularly blow-out fractures) and ocular trauma dominated reported injuries, attributed to blunt force distribution during a car crash with airbag deployment. Soft tissue lesions, chemical burns, and atypical fractures were also documented. Case analyses revealed that injury severity and pattern were highly variable, significantly influenced by risk factors such as pre-impact braking, seatbelt nonuse, and close occupant proximity to the steering wheel. These findings underscore that trauma prevention strategies must extend beyond the presence of safety devices to include public education on optimal occupant positioning and restraint system interactions. Furthermore, continued technological refinements aimed at mitigating deployment kinetics and chemical risks remain critical. Airbags provide indispensable protection in motor vehicle collisions, yet a balance between their lifesaving benefits and potential for injury requires multidisciplinary collaboration. Future efforts should integrate biomechanical research, clinical findings, and policy updates to improve occupant safety and optimize protective outcomes.

This work provides a thorough investigation focused on enhancing the fabrication parameters for pineapple leaf fiber (PALF)-reinforced low-density polyethylene (LDPE) composites by using advanced microwave-assisted heating techniques. Various statistical techniques, such as the Taguchi method, analysis of variance (ANOVA), and grey relational analysis (GRA), are used for multi-criteria optimization. The research investigated three key variables: microwave power, NaOH treatment percentage, and fiber reinforcement percentage. Each variable was tested at three different levels. It was observed that combined process parameters of 810 W microwave power, 10% NaOH treatment, and 50% fiber reinforcement resulted in the highest ultimate tensile strength (UTS) (13 MPa). The grey relationship grade (GRG) analysis has provided validation for this finding. From GRG, it was found that this specific combination of parameters has the highest impact on maximizing UTS. Furthermore, in the context of 3-point bending strength, the combination of parameters yielded an estimated bending strength value of 49.02 MPa. The integration of statistical methodologies and microstructural (scanning electron microscopy) examination offers essential insights for the advancement of composite materials. Thus, the improved performance attributes of sustainable polymer composites can be utilized in diverse sectors, such as construction, automotive, and aerospace.

Against the backdrop of the global trends toward lightweighting, multi-functionalization, and greening of materials, polypropylene (PP) has been extensively applied owing to its advantages of low density and low cost. However, its inferior foaming performance fails to meet high-end application requirements, which is primarily attributed to its low melt strength and restricted crystallization behavior. In this paper, the five-dimensional selection mechanism and classification of components for PP micro/nanocomposites fabricated via supercritical foaming are systematically summarized. The regulatory effects of micro/nano additives on the crystallization, rheological properties, and foaming behavior of PP are quantitatively analyzed. The parameter optimization windows of three foaming processes, namely batch foaming, extrusion foaming, and injection foaming, are integrated (e.g., a foaming temperature of 150-170 °C and a saturation pressure of 8-20 MPa). Additionally, the application progress of PP micro/nanocomposite foams in fields such as automotive lightweighting (with a weight reduction rate of 64.29%) and building thermal insulation (with a thermal conductivity as low as 29 mW/(m·K)) is outlined. The core novel insight of this work lies in clarifying the unified mechanism of crystal refinement induced by reinforcing agents with different geometric morphologies, which is dominated by the synergy between heterogeneous nucleation and steric hindrance. This finding provides theoretical and technical guidelines for the industrial-scale preparation of high-performance PP foams.

Carbon fiber reinforced polymer (CFRP) composites are widely used in many engineering applications such as aerospace, automotive, and defense industries due to their superior properties such as high specific strength, stiffness, and corrosion resistance. However, these materials require drilling, especially during assembly processes. Damage mechanisms arising during this process, such as delamination, high thrust force, and torque, negatively affect structural integrity and production quality. This study proposes a data-driven, multi-objective optimization approach to solve problems encountered during drilling in multi-walled carbon nanotube (MWCNT)-reinforced CFRP nanocomposites. The study considers the MWCNT reinforcement ratio, cutting speed, and feed rate as process parameters and examines their effects on thrust force, torque, and delamination factor. Second-degree polynomial regression-based prediction models were created using the experimental data obtained, and these models were included in the multi-objective optimization process. During the optimization phase, thrust force and torque values were simultaneously minimized, while the delamination factor was kept below the statistically determined constraint of Fd ≤ 1.054. Pareto-optimal solution sets were obtained using NSGA-II and MOPSO meta-heuristic algorithms in the solution process. The results indicate that suitable combinations of drilling parameters can be identified through Pareto-based optimization, allowing significant reductions in thrust force and torque while maintaining the delamination factor below the specified limit. The study presents a reliable optimization approach for the more efficient machining of CFRP nanocomposites.

Detecting transient "click" sounds during connector insertion is pivotal for automotive assembly quality but remains intractable due to high-intensity, non-stationary industrial noise. This paper introduces a physics-aware generative demasking framework that integrates acoustic spatial priors with conditional diffusion modeling. We propose the spatially conditioned diffusion probabilistic model (SC-DPM), where an ambient reference signal acts as a physical constraint to steer the reverse diffusion process. By exploiting the spatial decay of insertion sounds, this mechanism effectively disentangles the target transient from the background noise manifold, reconstructing high-fidelity spectro-temporal features. Discriminative temporal patterns are extracted using causal random convolutional kernels with causal dilations and local proportion of positive values (LPPV) pooling. Experiments on real-world datasets demonstrate 93.3% accuracy. The proposed "restore-then-classify" paradigm significantly enhances robustness against acoustic variability, establishing a scalable methodology for precise industrial monitoring under extreme noise conditions.

Elucidating the SO2 heterogeneous oxidation mechanism at the gas-liquid interface is critical for understanding haze formation. However, the dominant pathways and the oxidant's relative contributions remain ambiguous. This study developed a methodology that coupled a radical interfacial enrichment strategy with chemiluminescence (CL) detection, establishing a CL system capable of discriminating between the dissolved oxygen (DO) pathway and the non-DO oxidation pathway. By anchoring sorbic acid (SA)-functionalized Cr3+-doped ZnGa2O4 nanoparticles (ZGC NPs) at the interface of SO2 microbubbles, we constructed a highly efficient CL reaction interface with nanoscale characteristics. This design facilitated hydrogen-bond-driven spatial enrichment of SO2 and its radical intermediates at the gas-liquid interface. The radical-enriched interface induced a highly sensitive CL signal from the ZGC-SA-SO2 system, which displayed composite characteristics from both pathways. Deciphering the signals revealed that the heterogeneous oxidation mechanism of SO2 evolved dynamically with concentration. The dependence on the DO pathway decreased as the concentration increased. Additionally, the proposed method has been successfully implemented in the monitoring of automotive exhaust SO2 and the rapid assessment of food freshness. The generality of this approach was further demonstrated by the observable interfacial CL signals across various ZGC-type NPs-unsaturated fatty acid-SO2 systems. This work not only deciphers the dynamic, oxidant-dependent mechanism of SO2 oxidation but also establishes a universal platform for SO2 gas detection under mild conditions.

The demand for advanced automotive applications necessitated the development of 5G/6G multiple-input-multiple-output (MIMO) antennas. This work presents a low-profile antenna resonating at 5.9 GHz, suitable for vehicle-to-vehicle communication applications. The resonance is achieved through the use of a defected ground structure and geometric modifications to the radiator. The single element antenna is converted into a MIMO antenna by employing the elements perpendicular to each other. The unit cell antenna has dimensions of 12 mm × 11 mm, and the MIMO antenna measures 42.44 mm × 43.56 mm. The antenna reflection coefficient has been evaluated and is found to be less than -10 dB across the operating band. The tetra-port MIMO antenna achieves greater than 20 dB isolation without the use of any isolation structures. The proposed antenna shows the gain of 3.8 dBi, and efficiency of 87% at the operating frequency. Diversity parameters are evaluated to better understand the performance of the suggested MIMO antenna. The proposed MIMO antenna exhibits an envelope correlation coefficient below 0.1, a diversity gain above 9.9 dB, a total active reflection coefficient below -10 dB, channel capacity loss below 0.4 bits/s/Hz and MEG ratio is close to unity. When installed in the vehicle, the antenna is unaffected by interference from nearby radiators and the metal body of the car.

Cellulose, as an abundant and sustainable carbohydrate polymer, has emerged as a promising platform for radiative cooling due to the intrinsic infrared activity of its C-O-C and CC vibrational bonds. However, conventional cellulose material face critical challenges in cooling efficiency, environmental durability, and scalable fabrication for outdoor portable applications. Herein, inspired by the "flexible and tough" structure of pangolin scales, a biomimetic, scalable, and high-performance ultra-lightweight radiative cooling ZnO@ZIF-8 carboxymethylated fiber paper (ZZCFP) fabricated via in-situ growth of porous core-shell ZnO@ZIF-8 (ZZ) within a carboxymethylated cellulose paper (CFP) was developed. The tight binding and uniform dispersion of ZnO@ZIF-8 with CFP endow it with a hierarchical pore structure, simultaneously enhancing light scattering and thermal emission effects, leading to outstanding solar reflectance (98.2%) and high thermal emittance (96.5%). In addition, ZZCFP exhibits remarkable mechanical robustness (16.8 MPa tensile strength) along with superhydrophobicity, UV resistance, and biodegradability. Outdoor testing demonstrates a sub-ambient cooling effect of 15.4 °C under direct sunlight. Practical applications in automotive engine and temporary strawberry storage achieved cooling of 10.6 °C and 11.7 °C, respectively. This work provides a scalable and sustainable pathway to high-performance, durable radiative cooling materials, establishing a design paradigm for multifunctional cellulose-based composites in sustainable thermal management.

In this work, the tribological and corrosion behavior of commercially pure titanium-Ti-Gr2 with coatings obtained by mechanized contactless local electrospark deposition (LESD) with low pulse energy and a rotating electrode of TiB2-TiAl reinforced with ZrO2 and NbC nanoparticles was investigated. The current research is driven by the need for improved corrosion and abrasion resistance of titanium surfaces in automotive components, shipbuilding, aerospace, petrochemical and many other industrial and domestic areas. This work is a continuation of our previous study, in which the dependences of the relief, roughness, thickness, microhardness, composition and structure of the coatings obtained with this electrode on the electrical parameters of the LESD mode were studied and analyzed. In this work, the influence of the pulse parameters of the LESD process (respectively, roughness, thickness, composition and structure of the coatings) on the tribological and corrosion characteristics of the coatings has been investigated and the possibility of simultaneous protection of titanium surfaces from wear and corrosion has been demonstrated. Coatings containing nanocrystalline and amorphous-like structures have been formed, with synthesized new compounds and phases, and with increased hardness up to 13 GPa, low roughness Ra = 1.5-3 μm, thickness 8-20 μm and minimal structural defects. By comparing the potentiodynamic polarization curves, polarization resistance, electrochemical impedance and tribological characteristics of the coated surfaces, it has been established that their corrosion resistance increases by more than 1-2 orders of magnitude and their wear resistance during friction increases by 4-5 times compared to those of the substrate. Appropriate values of the electrical parameters of the LESD mode are presented, which allow obtaining uniform coatings with reduced roughness and structural defects, with predictable thickness, roughness and hardness, and with maximized corrosion and abrasive wear resistance to allow for uniform coatings with reduced roughness and structural defects, with predictable thickness, roughness and hardness, and with maximized corrosion and abrasive wear resistance.

Semiaromatic polyamides (SAPs) represent high-performance polymers that have a wide range of applications in the automotive and electronic industries for their exceptional strength and thermomechanical stability. Despite the maturity of existing synthetic techniques, developing a general method for the efficient construction of structurally diverse functional polyamides remains a significant challenge. We herein report a novel polyamidation methodology by carbonylation of hydroxylamine, where the amide joints between diene monomers were forged by relay hydroaminocarbonylation and Lossen rearrangement process. This strategy exhibits high regioselectivity and broad substrate generality, leading to a variety of structurally diverse SAPs with good thermal resistance. Departing from conventional polymerization, this catalytic system circumvents diacids preactivation and transcends the reliance on traditional diamines, which represents a promising alternative for developing advanced polyamide materials.

Hybrid metal-polymer components are used in many industries, such as in aerospace, automotives, and electronics, due to the possibility of reducing the weight of the final part while maintaining mechanical properties comparable to components made entirely of metal. Conventional 3D printing processes do not enable the direct fabrication of hybrid structures consisting of solid metal and polymer parts due to the significant differences in the processing temperatures of both materials. A solution to this problem is the integration of two processes, electrodeposition and photopolymerization, which allow fabrication to be carried out at room temperature. This paper presents preparatory studies aimed at developing a new 3D printing technology that uses the simultaneous application of electrodeposition and photopolymerization to manufacture hybrid metal-polymer elements in a single, integrated 3D printing process. Here, a hybrid metal-polymer element is defined as a component composed of at least two bonded parts, including at least one metal part fabricated by electrodeposition and at least one polymer part produced by photopolymerization. Thus, it is not a polymer component merely coated with an electrodeposited metal layer, but a true hybrid structure consisting of functional metallic and polymeric parts. Such components can be manufactured using the world's first hybrid 3D printer, which integrates electrodeposition and photopolymerization to produce metal-polymer hybrid parts within a single 3D printing process (the device has been submitted to the Polish Patent Office). However, its design and operating principle are beyond the scope of this paper. The presented research focuses on initial study of selected feedstock materials for this printer, namely photocurable resins and electroplating baths. Since the entire hybrid printing process occurs in an electroplating bath environment, studies of these materials for 3D printing under such conditions were essential. This work includes a screening study of photocurable formulations with respect to rheological properties, 3D printing tests in a model copper electroplating bath, and selection of a suitable bath brightener to maximize the quality (fine grain size, homogeneous grain distribution) of additively deposited copper layers. The study was conducted using copper electrodeposition and acrylate resin photopolymerization as model processes for evaluating the proposed hybrid metal-polymer 3D printing technology. Finally, the most suitable feedstock materials for producing metal-polymer hybrid parts via the proposed 3D printing method were selected.

The growing need for lightweight, multifunctional, and high-performance structures in the automotive, aerospace, electronics, and medical industries has driven the development of advanced joining technologies for polymers and metal-polymer combinations. Among these, ultrasonic welding (USW) and friction stir spot welding (FSSW) have emerged as promising solid-state techniques capable of producing reliable joints with minimal thermal degradation and enhanced interfacial bonding. This review focuses on recent developments in USW and FSSW of thermoplastics, fiber-reinforced composites, and hybrid metal-polymer systems, with a particular emphasis on process mechanics, microstructural evolution, and joint performance. The mechanisms of heat generation, material flow behavior, and consolidation are discussed in relation to key process parameters, including applied pressure, rotational speed, vibration amplitude, plunge depth, and dwell time. Microstructural transformations such as polymer chain orientation, recrystallization, interfacial diffusion, and defect formation are analyzed to establish process-structure-property relationships. Mechanical performance metrics, including lap shear strength, fatigue resistance, impact behavior, and environmental durability, are critically compared across different materials and welding methods. Furthermore, recent advances in numerical and thermo-mechanical modeling, in situ process monitoring, and data-driven optimization are discussed to highlight pathways toward predictive and scalable manufacturing. Current industrial applications and existing limitations such as challenges in automation, thickness constraints, and hybrid material compatibility are also evaluated. Finally, key research gaps and future directions are identified to improve joint reliability, sustainability, and broader industrial adoption of advanced solid-state welding technologies.

Flexible acceleration sensors demonstrate revolutionary potential in healthcare, structural vibration monitoring, and consumer electronics owing to their unique conformal adhesion capability and mechanical adaptability. However, current academic research presents two distinct paradigms for realizing flexibility: one is the hybridly flexible sensor, which incorporates traditional micro-electro-mechanical System (MEMS) acceleration sensor chips with flexible packaging/substrates; the other is the intrinsically flexible sensor, whose sensing unit and substrate are entirely composed of flexible materials enabled by microstructural design. This review first analyzes the fundamental differences and design challenges between these two flexible architectures. It then systematically elucidates five core sensing mechanisms-capacitive, piezoresistive, triboelectric, piezoelectric, and electromagnetic-comparing their working principles, material systems, structural designs, and performance metrics. Among these, piezoelectric and triboelectric types exhibit distinctive advantages in self-powering capability, whereas resistive and capacitive approaches offer greater ease of integration. Furthermore, the applications of intrinsically flexible acceleration sensors in structural health monitoring, wearable devices, automotive safety, and other fields are discussed, with particular emphasis on their unique strengths in real-time vibration monitoring. Finally, the review summarizes existing challenges, such as the trade-off between sensitivity and flexibility, and provides theoretical insights to guide future innovations in intrinsically flexible acceleration sensor technology.

Sound absorption in porous materials is fundamentally governed by their microstructural morphology yet establishing a quantitative and design-oriented relationship between microstructure and acoustic behavior remains challenging. To address this challenge, a deep learning-based acoustic modeling framework is proposed for analyzing the microstructure of flexible polyurethane (PU) foam and predicting its acoustic performance. A microscopic analysis model is developed to semantically segment SEM images using a U-Net model and quantitatively extract the distribution parameters of microstructural properties, including cell size, pore size, pore shape factor, and strut thickness. An artificial neural network model is developed to model the relationship between these microstructural parameters and acoustic performance measured using an impedance tube, based on 210 flexible PU foam samples including thermally aged and non-aged materials from multiple manufacturers. Finally, the proposed approach is validated through comprehensive performance evaluation, comparison with experiments and alternative methods, and analysis of microstructural parameter contributions. The validated framework establishes a quantitative link between microscale morphology and acoustic performance, providing data-driven acoustic insights and practical guidance for acoustic material design, including feature selection, optimization of acoustic performance, and fabrication of sound-absorbing materials for applications such as automotive and construction.

Disposal of solid plastic waste is one of the major challenges facing most countries, especially developing countries. In this study, waste polystyrene foam (WPS) and polyethylene terephthalate (PET) from waste plastic bottles were recycled. The waste PET was chemically recycled using a glycolysis technique to obtain the glycolyzed product (GPET) and subsequently unsaturated polyester. WPS was also mechanically recycled using a hot blending technique. Polyvinyl chloride, GPET, and the prepared polyester were added as multifunctional additives and their effects were compared with conventional additives such as dioctyl phthalate (DOP). The effect of these additives on the rheological, mechanical, and electrical properties was studied. Thermal stability, fire retardancy and morphology of the WPS/PVC blends were also evaluated. Results showed that polyester significantly improved melt flow rate (up to 0.975 g/10 min), flame retardancy (burning rate reduced to ~ 0.5 mm/s), and decreased combustion energy (~ 404 cal). GPET enhanced tensile strength (21.96 MPa) and elongation at break (37%). Additives increased permittivity and conductivity, while polyester exhibited the strongest dielectric response due to enhanced interfacial polarization. SEM analysis confirmed better dispersion and compatibility in GPET and polyester blends. Based on the results, the developed blend shows strong potential for use in applications requiring enhanced mechanical, thermal stability, and flame retardancy as electrical insulation, construction materials, and automotive components.