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Passive Thermal Management of Battery Disconnect Units for Fast-Charging Electric Vehicles: A Comparative Study of Phase Change Material Heat Transfer Configurations2026-01-0759To be published on 07/01/2026
Reducing charging time remains a critical challenge for the widespread adoption of electric vehicles (EVs). Limited charging infrastructure availability, combined with the long duration required for battery recharging, significantly affects user acceptance. As a result, fast-charging technologies are increasingly being introduced in both newly designed EV platforms and existing vehicles through retrofitting solutions. Despite their benefits, fast-charging systems impose substantial thermal loads on vehicle components, charging stations, and associated power electronics. Excessive heat generation can compromise performance, reliability, and safety, making effective thermal management a key design concern. Within the high-voltage architecture, the Battery Disconnect Unit (BDU) plays a vital role by monitoring and controlling the connection of the battery to the powertrain and charging system. Traditionally, BDUs are designed for conventional charging power levels; however, higher
Salameh, Georges, Goumy, Guillaume, Frecinaux, Anthony, Ratajczack, Christelle, Palluel, Marlène, Noiseau, Pascal, Lardeux, Sébastien
Optimization of a Halbach array for torque ripple reduction in a Yokeless And Segmented Armature axial flux machine2026-01-0754To be published on 07/01/2026
This paper presents the optimization of a Halbach magnet array applied to an axial flux machine (AFM) in a 12-pole, 18-slots yokeless and segmented armature (YASA) topology, evaluated in the torque–speed characteristics diagram. AFMs offer significant advantages in terms of compact design and high torque density compared to other permanent magnet machine topologies. However, noise, vibration, and harshness (NVH) performance is strongly influenced by cogging torque, electromagnetic torque ripple, and tooth forces. While Halbach magnet arrays are well established in high-performance radial flux machines, only limited research has investigated their influence in AFMs. A Halbach array concentrates magnetic flux on one side of the magnet arrangement, leading to increased air-gap flux density and a more sinusoidal magnetic field distribution. By using a Halbach array, the magnetic field distribution in the air gap becomes more sinusoidal, thereby reducing harmonic components. Previous
Müller, Karsten, Schulz, Fabian, Bremer, Martin, Burkhardt, Yves, De Gersem, Herbert
Integrated DC Boost Charger in Post-800V Architecture with Open-End Winding Machine – Magnetic-Domain Modelling and Torque Analysis2026-01-0739To be published on 07/01/2026
Next-generation powertrain architectures proposed within EU Horizon projects adopt operating voltages above 800 V, providing improvements in efficiency as well as reductions in copper usage and system weight. However, post-800 V vehicles must remain backward compatible with existing 400 V and 800 V charging infrastructure, which requires the installation of an additional onboard DC boost charging unit on the vehicle. This paper proposes an integrated DC boost charging solution that reutilizes the open-end winding electric machine and the traction inverter of the electric powertrain, enabling backward compatibility while further reducing system cost and weight. In charging mode, the electric machine is repurposed as a passive inductive component, imposing a strict requirement of stationary operation with zero torque generation, which fundamentally differs from the driving mode characterized by rotor rotation and electromagnetic torque production. Consequently, conventional electric
Wang, Haoran, Kallur-Krishnamoorthy, Rajesh, Neuhaus, Christoph, Andert, Jakob
Biofuel Effect on Regeneration Capability and Soot Reactivity in SCRoF Systems2026-01-0750To be published on 07/01/2026
Biodiesel blends (B7, B20, B100) were evaluated in a Stage V-compliant SCR on Filter (SCRoF) system for heavy-duty applications to quantify soot reactivity and filter regeneration capability. Compared to conventional diesel (B7), B20 showed slightly faster regeneration performance under real-driving conditions, while B100 resulted in reduced particulate formation and higher soot reactivity, with more intense exothermic events requiring careful management. These differences are attributed to the distinct physical-chemical properties of the fuels (oxygen content, lower heating value) and their interaction with Diesel Oxidation Catalyst (DOC)/SCRoF. All tests were conducted on an engine dynamometer with a Cursor 9 FPT (Fiat Powertrain). Findings are discussed in the context of EU Stage V limits and practical control strategies for heavy-duty applications.
Costa, Simone
Key Modeling Considerations for Reliable FEM-Based Demagnetization Evaluation of IPMSM2026-01-0741To be published on 07/01/2026
The reduction of heavy rare earth elements such as dysprosium and terbium, which are associated with high cost, geopolitical risk, and sustainability concerns, is a key objective in the electromagnetic design of IPMSM for traction applications. As these elements are the primary contributors to magnet intrinsic coercivity, their minimization increases the risk of irreversible demagnetization of the permanent magnets. In IPMSM designs with reduced heavy rare earth content, it is therefore necessary to operate close to the demagnetization limit of the permanent magnets and accurately identify them. Consequently, precise and reliable finite element based prediction of demagnetization robustness is essential for systematic and material efficient machine design. This paper investigates the key factors required for reliable assessment of demagnetization robustness in IPMSM using electromagnetic FEM. Unlike existing literature, which typically neglects the accuracy of magnet material data
Malner, Max, Naumoski, Hristian, Gretzinger, Stefan, Izquierdo, Patrick, Kulzer, Andre Casal
Validation of an adaptive order Finite Element model for transmission loss simulation of trimmed automotive structures2026-01-0707To be published on 06/20/2026
Vehicle electrification and increasing demands for driving comfort present significant challenges for designing effective noise control treatments in modern vehicles. Lightweight, low-emission designs often compromise acoustic efficiency. One way of compensating this is through the use of multi-layer ‘trim’ material configurations to mitigate noise across a wider frequency range. Traditional 3D finite element models, while accurate and even needed to capture the full dynamic behaviour, become computationally prohibitive for complex automotive structures like firewalls, which feature intricate shapes, high curvature, and material compression. This computational burden limits design exploration and timely noise performance predictions. This paper introduces the use of an innovative adaptive higher-order finite element method to address these challenges. The method utilizes a fixed finite element discretization of trim components and surrounding acoustic fluid, incorporating an automated
Van Genechten, Bert, Vansant, Koen, Purohit, Bimal, Effinger, Veronika
Effect of Backing PU Foam Material Properties on Acoustic Insulation Pad Insertion Loss2026-01-0678To be published on 06/20/2026
The effect of backing PU foam material on the insertion loss of insulation pads was investigated. First, the material properties affecting the resonant frequency—which determines the insertion loss—were theoretically identified, and practical methods for calculating both the resonant frequency and the insertion loss of the insulation pad were developed. These methods were then applied to evaluate how changes in material properties influence the resonant frequency and insertion loss of the insulation pad. It was found that Young's modulus, Poisson's ratio, and thermal characteristic length are the primary material properties that affect these outcomes. The optimal levels of these properties, which are beneficial for interior noise reduction, are derived and presented in this study.
Chae, Ki-Sang, Lee, Moonseok, Kim, Hyunwoo
Optimizing recycled and recyclable PET felt lightweight formulations for best acoustic insulation as poroelastic springs with minimum weight2026-01-0702To be published on 06/20/2026
For sustainability reasons, the automotive market is requesting 100% mono-material noise treatments, particularly for the end-of-life recycling without any part separation operation. But also, the OEMs require super light, highly performance insulating noise treatments for electric vehicles in order to extend vehicle autonomy. PP meltblown fiber felts present good mono-material characteristics with very good absorption, but generally not so good insulation properties behind an airtight barrier due to lack of stiffness. Moreover, these PP meltblown fiber felts are relatively expensive and not thermoformable, thus obliging to use them as 2D die-cut parts behind existing hard or soft trims classically. The optimization approach proposes to return to 100% thermoformable recycled and recyclable PET formulations blending unusual coarse mechanical specific fibers, in order to optimize the viscothermal exchanges, while maintaining good mechanical properties, with microfibers for best
Duval, Arnaud, Lei, Lei, Wilkinson, Alexandre, Delinselle, Eric
Field-Based Evaluation of Physiological Fatigue Reduction in Fuel Cell Refuse Collection Vehicle Using Heart Rate Variability2026-01-0690To be published on 06/20/2026
This study compared the physiological fatigue of drivers and accompanying workers operating diesel-powered (DI) and fuel cell-powered (FC) garbage compactor trucks under real-world working conditions. Reducing driver fatigue is critical for ensuring occupational safety and maintaining work efficiency, as fatigue in waste collection tasks is influenced by multiple factors such as vibration, noise, and vehicle operation characteristics. In this study, heart rate sensors and smartwatches were used to continuously monitor physiological responses during identical driving routes. Fatigue was evaluated using heart rate variability (HRV) indices—specifically, the root mean square of successive differences (RMSSD) and Lorenz plot (LP) area—calculated from RRI data. The results indicated that the RMSSD of drivers in FC trucks was approximately 60% higher and their LP area about 50% larger than those in diesel trucks. For accompanying workers, RMSSD was around 20% higher and LP area approximately
Utsumi, Atsuko, Yakoh, Takahiro
High-Fidelity NVH Analysis Model Development Process for EV Traction Motors Based on Experimental Correlation2026-01-0685To be published on 06/20/2026
This study presents a high-fidelity NVH (Noise, Vibration, Harshness) analysis model development process for EV traction motors. The proposed process consists of two main components: Path refinement through structural stiffness tuning, and Source refinement, focused on the motor’s excitation mechanisms. Model accuracy was validated through comparison of simulation results with dyno test data, with particular focus on the 24th-order electromagnetic vibration observed in an 8-pole, 48-slot motor. Path refinement was achieved through modal correlation between experimental results and finite element (FE) analysis. Nine modal test and simulation stages were conducted, ranging from individual components to the complete motor assembly. Mode shapes were compared using the Modal Assurance Criterion (MAC), and natural frequencies were matched within a 5% error margin by adjusting FE material properties. For the 24th-order electromagnetic vibration, simulation results agreed with test data within
Kim, Donghee, Kim, Dong-Jun, Lee, SangHan, Kim, Seon Hyeong, Hwang, Seung Gyu, Valente, Giorgio, Parisouz, Shahriar, Halse, Christopher
Bridging Simulation And Reality: Incorporating Seal Contact Detachment Into Stick–Slip Prediction2026-01-0714To be published on 06/20/2026
Preventing stick–slip in virtual vehicle development combines virtual displacement data with experimental sliding tests. If the calculated relative displacement at a contact exceeds the distance of two stick–slip impulses, that contact could be a potential noise source. Such risks can be mitigated only by design changes or alternative sealing concepts. Stick–slip tests provide the experimental reference, showing how often a frictional pairing produces impulses over a defined sliding distance. The basis for this assessment is Multibody Dynamics (MBD) simulations, which compute component deformations during virtual drives and derive relative displacements at contact interfaces (e.g. in the sealing gap between body and closure), representing the theoretical sliding distance that enables stick–slip effects. Yet, this combined approach has overlooked a critical factor: the deformability of automotive seals. Due to their elastomeric properties and geometry, seals can elastically follow
Strangfeld, Martin, Fritz, Susanne, Weber, Jens, Rosell, Anneli
Towards Realistic Stick-Slip Testing: Efficiently Mapping Material Behaviour across a wide Range of Loading Conditions2026-01-0713To be published on 06/20/2026
To minimise noise caused by interior components rubbing against each other, automotive materials are usually tested in advance with the established stick-slip method according to VDA standard 230-206. This procedure is widely used for soft materials, upholstery and plastics. However, it is limited to constant climatic and selected loading conditions. Contrary, in real application, changing climates and dynamic excitations can nevertheless trigger noise issues even in materials rated as suitable in the prior tests. To address this gap, a new test method has been developed that evaluates the stick-slip behaviour of material combinations for a wide range of loading and climatic conditions. Conducted in a climate chamber with a standard stick-slip bench, the procedure applies sinusoidal excitations, dynamic climatic shifts and advanced data analysis. In addition to the usual results the new method also evaluates realistic scenarios such as starting a vehicle in different seasons or sudden
Fritz, Susanne, Strangfeld, Martin
Dynamic characterisation and modelling of Electric Cables under representative load conditions2026-01-0676To be published on 06/20/2026
Electric high voltage (HV) cables are commonly used in automotive applications and very prominently in electrified vehicles. These cables are potential flanking transmission paths for structure-borne sound in a broad frequency range and must therefore be included in the NVH design process. Electrical high voltage cables exhibit non-linear mechanical characteristics, when exposed to significant bending the internal geometry of the cable will change and a curvature dependent bending stiffness will result. The electrical cables envisaged in the current publication feature a helically wound stranded aluminium wire core. This conductive core is covered by, in sequence, a silicone rubber insulation, a braided aluminium wire shield with aluminium foil to minimize electromagnetic interference and a silicone rubber outer sheath. An extensive measurement campaign was carried out to dynamically characterize cable specimen of different lengths and cross sections in terms of multi-degree of freedom
Nijman, Eugene, Buchegger, Blasius, Böhler, Elmar, Zeller, Bernhard, Rejlek, Jan, Faksa, Lukáš, Lukavsky, David
Nickel-Copper Alloy, Corrosion Resistant, Tubing, Seamless 67Ni - 31Cu AnnealedAMS4574F (Current)6/15/2026
This specification covers a corrosion-resistant nickel-copper alloy in the form of seamless tubing.
AMS F Corrosion and Heat Resistant Alloys Committee
Carburizing and Heat Treatment of Carburizing Grade Steel PartsAMS2759/7F (Current)6/15/2026
This specification, in conjunction with the general requirements for steel heat treatment covered in AMS2759, establishes the requirements and procedures for three classes of gas, vacuum, liquid, and low-pressure carburizing (LPC) and related heat treatment of parts fabricated from carburizing-grade steels. Parts made from steels other than those specified in the detail specifications may be heat treated in accordance with the applicable requirements using processing temperatures, times, and other parameters recommended by the material producer. This specification does not cover pack carburizing.
AMS B Finishes Processes and Fluids Committee
Phosphor Bronze, Sheet, Strip, and Plate, 94.5Cu - 4.0Sn - 0.19P, Spring Temper (H08)AMS4510K (Current)6/15/2026
This specification covers a copper alloy (phosphor bronze) in the form of sheet, strip, and plate (see 8.6).
AMS D Nonferrous Alloys Committee
Aluminum Alloy, Plate, 4.0Zn - 2.0Mg - 0.32Mn (7019-T651), Solution Heat Treated, Stress Relieved, and Artificially AgedAMS4409B (Current)6/15/2026
This specification covers an aluminum alloy in the form of plate 0.500 to 4.500 inches (12.7 to 114.3 mm), inclusive, in nominal thickness (see 8.5).
AMS D Nonferrous Alloys Committee
Aluminum Alloy Castings, 7.0Si - 0.58Mg - 0.15Ti (E357.0-T6), Solution and Precipitation Heat TreatedAMS4288A (Current)6/15/2026
This specification covers an aluminum alloy in the form of castings (see 8.10).
AMS D Nonferrous Alloys Committee
Steel, Bars, Forgings, Mechanical Tubing, and Forging Stock, 1.4Mn - 1.5Si - 0.30Cr - 1.8Ni - 0.40Mo (0.23 - 0.28C) (HY-TUF), Premium Aircraft-Quality, Consumable Electrode Vacuum MeltedAMS6425G (Current)6/15/2026
This specification covers a premium aircraft-quality, low-alloy steel in the form of bars, forgings, and mechanical tubing 225 square inches (1452 cm2) and under in cross-sectional area and forging stock of any size.
AMS E Carbon and Low Alloy Steels Committee
Chemical Check Analysis Limits, Corrosion- and Heat-Resistant Steels and Alloys, Maraging and Other Highly Alloyed Steels, and Iron AlloysAMS2248H (Current)6/15/2026
This specification defines limits of variation for determining acceptability of composition of cast and wrought corrosion and heat-resistant steels and alloys, maraging and other highly alloyed steels, and iron alloy parts and materials acquired from a producer.
AMS F Corrosion and Heat Resistant Alloys Committee
BOLT, TEE HEAD - AMS5662, CHAMFERED, .2500-28 UNJF-3A (STRESS RUPTURE RESISTANT)AS3410C (Current)6/12/2026
E-25 General Standards for Aerospace and Propulsion Systems
Challenges in Predicting Fatigue Damage during Agricultural Operations: Insights from Machine Learning Models02-19-03-00176/10/2026
Agricultural vehicles operating in rough environments experience increased fatigue damage accumulation, which may decrease machine safety and reliability. Autonomous agricultural machines offer an opportunity to incorporate fatigue damage considerations into path planning. This work investigates whether machine learning can predict fatigue damage to a tractor chassis using light detection and ranging (LiDAR)-based terrain features, vehicle speed, and rotational vehicle state data (e.g., triaxial angle, angular velocity, and angular acceleration). Fatigue damage was estimated using the Rupp filter and the Durability Transfer Concept. Following poor predictive performance of the machine learning models, an exploratory analysis of damage histograms, dominant frequency, and acceleration magnitude was performed. Results indicated that most estimated fatigue damage occurred in the 0–2 Hz band, which coincides with the frequency range of terrain-induced acceleration. On-road driving led to
Govers, Megan Emily, Hamilton-Wright, Andrew, Hassan, Marwan, Oliver, Michele L.
Identification and Assessment of Damage to Composite Aircraft Structures Training DocumentAIR6825 (Current)6/10/2026
Individuals who complete the applicable modules aligned with this training document will be able to define the type of damage, define the extent of damage, determine if further inspection is required, evaluate the damage against published allowable damage limits, and provide accurate documentation of the damage. The intended outcome of the training is increased safety such that no aircraft is released with unknown damage and that the aircraft meets continued airworthiness requirements. The goal is to change the culture from damage discovery to damage reporting while also reducing or eliminating flight delays due to incorrect or insufficient information. Teaching levels have been assigned to the curriculum to define the knowledge, skills, and abilities graduates will need. Minimum hours of instruction have been provided to ensure adequate coverage of all subject matter including lecture and practical exercise. These minimums may be exceeded and may include an increase in the total
AMS CACRC Commercial Aircraft Composite Repair Committee
Unidirectional Carbon Fiber Tape Epoxy Repair Prepreg, Vacuum Curing Part 2 - Qualification Program for Fiber, Carbon Fiber Tape Prepreg, and Film AdhesiveAMS6885/2 (Current)6/10/2026
AMS6885/2 gives specific information about the qualification program for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The prepreg system shall include an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
STUD, LOCKED IN, KEY LOCKED, UNS S66286, 140 KSI/1200 °F LIGHTWEIGHT, SELF-BROACHING KEYSAS3543B (Current)6/10/2026
E-25 General Standards for Aerospace and Propulsion Systems
Unidirectional Carbon Fiber Tape Epoxy Repair Prepreg, Vacuum Curing Part 0 - IntroductionAMS6885 (Current)6/10/2026
This document (Technical Specification) gives information about qualification rules and the relation between the different specification parts involved, such as the Technical Specification (TS), the Material Specification (MS), and the Purchasing Specifications (PS).
AMS CACRC Commercial Aircraft Composite Repair Committee
Unidirectional Carbon Fiber Tape Epoxy Repair Prepreg, Vacuum Curing Part 1 - General RequirementsAMS6885/1 (Current)6/10/2026
AMS6885/1 gives information about the technical requirements and qualification procedure for unidirectional carbon fiber tape epoxy repair prepreg capable of curing under vacuum for repair of carbon fiber reinforced epoxy structures. The repair system includes an epoxy film adhesive to be applied in a co-bonding process with the prepreg for solid laminate and sandwich bonding.
AMS CACRC Commercial Aircraft Composite Repair Committee
Aircraft Surface Coating Interaction with Aircraft Deicing/Anti-Icing FluidsAIR6232 (Current)6/10/2026
This SAE Aerospace Information Report (AIR) provides descriptions of test methods for determining if an aircraft surface coating of any thickness has adverse effects on aircraft deicing/anti-icing fluids with respect to fluid holdover time performance and aerodynamic performance. Although not the primary mandate of the G-12 Aircraft Ground Deicing Committee, this document also provides descriptions of suggested test methods for evaluating aircraft surface coatings with respect to durability, hardness, weathering, aerodynamic drag, ice adhesion, ice accumulation, contact angle, and thermal conductivity. These additional tests can provide informational data for characterizing the coatings and may be useful to operators when evaluating the coatings.
G-12ADF Aircraft Deicing Fluids
Requirements Extract for AS5127D Aerospace Standard Test Methods for Aerospace Sealants Methods for Preparing Aerospace Sealant Test Specimens SA-DIG-000026/9/2026
This digital standard is a requirements extract of AS5127D Aerospace Standard Test Methods for Aerospace Sealants Methods for Preparing Aerospace Sealant Test Specimens. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
Design-Driven Sustainability of Automotive Components: A Comparative LCA from Conventional to Metal and Composite Additive Manufacturing2026-37-00376/9/2026
The increasing pressure to decarbonize manufacturing systems is pushing industry beyond conventional lightweighting strategies toward material and process paradigms, capable of delivering functional performance with radically lower environmental impact. In this context, polymer-based composite Additive Manufacturing (AM) offers an underexplored yet highly promising pathway for sustainable production of load-bearing components. This study presents a preliminary comparative cradle-to-gate Life Cycle Assessment (LCA) of a Formula SAE brake pedal, assessing the environmental transition from conventional sheet metal fabrication and finishing operations of Aluminum 7075-T6 to additive manufacturing solutions, with specific focus on Carbon-Fiber-Reinforced Polymer (CFRP) composites. Two topology-optimized designs, respectively for Powder Bed Fusion (PBF) in AlSi10Mg and Material Extrusion (MEX) in Polyethylene Terephthalate Glycol with Carbon Fiber (PETG-CF) are compared to conventional
Dalpadulo, Enrico, Russo, Mario, Apté MD, Raphaëlle, Leali, Francesco
A Predictive Methodology for 3D-CFD Simulation of Piston Thermal Field in Sustainable High-Performance Engines2026-37-00026/9/2026
In recent years, especially in high-performance spark-ignition engines, the thermal stress of pistons has gradually increased due to the implementation of various technologies, aimed at meeting emission reduction and specific power increase requirements. If the heat is not properly dissipated, cracking and plastic deformation of the material as well as formation of hot spots triggering pre-ignition in the combustion chamber mixture can occur. This last aspect is even more true considering innovative fuels such as hydrogen. To overcome these problems, one or more jets of oil are directed towards the piston under-crown region, impacting at high speed. This technique ensures immediate cooling and allows the engine performance to be increased without compromising the useful life. In order to optimize the oil jet effectiveness, 3D-CFD can be proficiently adopted. In this regard, the aim of this work is to define a robust numerical methodology able to simulate oil jet impingement and piston
Duni, Andrea, Berni, Fabio, Breda, Sebastiano, Fontanesi, Stefano, Gilioli, Filippo
Passenger Car Powertrain for Voltages above 800V2026-37-00206/9/2026
The EU funded innovation project High-Voltage fast-charging Efficient electric vehicle Powertrains (HiVEP) develops innovative technologies for mass-market electric vehicles (EVs) by advancing architectures operating above 800 V. These architectures integrate silicon carbide (SiC)-based power electronics, rare-earth-free electric machines with active winding reconfiguration, high C-rate batteries, and optimized thermal management systems. HiVEP aims to enable fast charging in less than ten minutes, reduce energy consumption by at least 25%, extend the driving range by 20%, and cut system costs by up to 20% in volume production. This article deals in detail with the project objectives, the methodological approach, and the expected key innovations, as well as the technical, environmental, and social impacts. The discussion situates HiVEP within the European research and innovation landscape, emphasizing its role in accelerating adoption of sustainable mobility solutions.
Schernus, Christof, Nada, Shady, Neuhaus, Christoph, Ewald, Jens, Swierc, Daniel, Kallur-Krishnamoorthy, Rajesh, Vasiliadis, Harilaos
Improvement of rCF Behaviour through the Introduction of NF2026-37-00396/9/2026
This study investigates the structural improvement of recycled carbon fibre composites through hybridisation with continuous flax fibres to address sustainability concerns and performance limitations. Recycled carbon fibres, while environmentally beneficial, suffer from short, randomized orientations and lower mechanical properties limiting their application beyond decorative uses. This research explores whether incorporating unidirectional flax fibres can enhance rCF behaviour for structural applications. Six hybrid composite layup variants and two plain composites were manufactured using cold compression moulding with Ampro Bio Resin. Each hybrid configuration comprised eight layers, divided into four layers of recycled carbon and four layers of flax fibres oriented at 0°. Complete mechanical characterization was performed following ISO standards for tensile (ISO 527), flexural (ISO 178), and impact (ISO 179) testing. Results demonstrated significant performance improvements in
Hnatyk, Dawid, Chrysanthou, Andreas, De Vuyst, Tom, Ismail, Sikiru
Investigation of the Combustion of Stearic Acid-Coated Pure Aluminum Powder as Additives in Biodiesel and Diesel Blends04-19-02-00106/8/2026
In the present study, research was conducted to increase the combustion efficiency in a diesel engine by adding 100 and 200 ppm aluminum powder to diesel and biodiesel (produced from 10% spent coffee ground oil and 90% waste cooking oil) blends. Aluminum powder is a flammable metal. Due to this feature, it has been used as an additive to liquid fuels in many studies in the literature. In general, it has been reported that thermal efficiency increases with the addition of aluminum particles. However, the high explosion sensitivity of aluminum can affect its stable combustion. In addition, Al is a metal that can be easily oxidized. Therefore, coating aluminum is considered a good solution. Stearic acid has been suggested in the literature as a suitable material for coating aluminum. In this study, stearic acid, a saturated fatty acid, was used to coat aluminum particles. Stearic acid is a good surfactant, hydrophobic substance, and plasticizer. It is also a more environmentally friendly
Kül, Volkan Sabri, Akansu, Selahaddin Orhan, Sarıtaş, Mehmet
Quantifying Life Cycle Environmental Impact of Emerging Aluminum High-Pressure Die Cast (HPDC) Mega-Castings Replacing Stamped Steel Solutions13-07-01-00046/4/2026
Over the last few years, there has been an uptick in the exploration and implementation of aluminum high-pressure die casting (HPDC) mega-castings as replacements for conventional stamped steel parts in vehicles. This trend is expected to increase with common justifications, including claims of reduced costs and lower environmental impacts associated with the replacement of dozens of individual parts with a single casted piece, along with reduced demands on associated tooling and machinery. However, the data and literature to support these claims are limited and at times contradictory, with some studies showing increased costs and energy demands for mega-casting technologies. This study presents the results of a literature review and a gate-to-gate life cycle inventory (LCI) adapted from conventional HPDC aluminum casting unit processes that may be used to quantify potential life cycle global warming potential (GWP), cumulative energy demand (CED), and other environmental impacts of
Sebastian, Brandie, Balzer, Russ
Electrical and Copper Compatibility Studies of Transmission Lubricants for Advanced Electric Vehicles2026-01-50366/3/2026
Improved energy efficiency and lower CO2 emissions are the two major drivers for the emergence of E-mobility. Growth of electric vehicles (EVs) has sustained ever since their introduction till 2020 and has substantially increased thereafter. EVs require specialized lubricants, which are different from conventional lubricants mainly due to the addition of new hardware technology including e-motor, inverter, battery, and new materials (copper windings, elastomers, plastic, and other materials). Lubricant when used in an advanced powertrain electric vehicle specifically in E-powertrains may encounter the e-motor and must deliver unique performance attributes such as optimal electrical properties, thermal management, and material compatibility apart from the traditional features including extreme pressure, friction performance, oxidation, and wear control. In the current study, we have investigated conventional GL5, manual transmission fluid (MTF), automatic transmission fluid (ATF), and
Katta, Lakshmi, Seth, Sarita, Singh, Sandeep, Bhardwaj, Anil, Arora, Ajay Kumar
WASHER, KEY - 90°, LOCKING, CRES, UNS S32100AS9581D (Current)6/3/2026
E-25 General Standards for Aerospace and Propulsion Systems
Polymer vs. Metal Seals: A Comparison In Critical Space Systems26AERP06_036/1/2026
Sealing systems in space applications must perform reliably under demanding conditions in engineering: cryogenic temperatures, vibration, leakage control, ultra-high vacuum, ionizing radiation, abrasive particulates, and repeated thermal cycling. Each factor strains conventional sealing technologies. In combination, they can rapidly cause failure in systems where margins are unforgiving and maintenance is impossible. As spacecraft architectures evolve toward longer operational lifetimes and broader mission profiles, sealing requirements continue to tighten. Launch vehicles, satellites, and exploration platforms now operate across wider temperature ranges and in contact with more aggressive propellants and media. As a result, both metal seals and engineered polymer alternatives are evaluated-and selected-against increasingly specific, measurable performance criteria.
European Researchers Develop Self-Healing Composite Material for Spacecraft26AERP06_116/1/2026
Researchers from CompPair and the European Space Agency have developed a new composite material for spacecraft with an embedded healing agent. European Space Agency, Paris, France Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM, and Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fiber product for use in space transportation. Project Cassandra - an abbreviation for Composite Autonomous Sensing and Repair - includes sensors and a heating element within a composite carbon-fiber material, allowing spacecraft to autonomously repair initial stages of damage.
Mitigating Cracking in COP Optics through Annealing and Step-Torquing2026-26-07646/1/2026
Polymeric optical materials such as Cyclo Olefin Polymer (COP) are adopted in aerospace lighting systems due to their excellent optical clarity, dimensional stability, moldability and weight saving advantages over glass. However, their relatively low toughness and the presence of residual molding stress make them prone to crack initiation during mechanical fastening. During its installation, crack formation was consistently observed around self-tapping screw interfaces, raising concerns over reliability, maintainability, and compliance with durability requirements. A structured Design of Experiments (DOE) was performed to identify root causes and evaluate potential mitigation methods. The investigation revealed that residual stresses in the COP material, combined with localized stress concentrations during screw tightening, were the primary drivers of crack initiation. Two complementary process improvements were identified and validated as part of mitigation plan: (i) annealing of the
S, Nikhil, Singh, Abhimanyu Kumar, Katageri, Praveen, SP, Pradeep, Chandra, Praveen
Drilling Studies on Sustainable Lightweight Hybrid Polymer Matrix High-Performance Nanocomposites2026-26-07326/1/2026
Worldwide, engineers are exploring the possibility of using polymer composites in their quest for lightweight materials. In this study, injection moulding was used to develop a biodegradable polymer PLA composite containing 20 wt.% vetiver fibers (VFs) and 2 wt.% nano-silica (nSiO2) obtained from pearl millet, which is sustainable. Materials need machining as secondary operation that required joining. Desirability analysis was used to examine and optimize machining (drilling) studies that were designed with Taguchi's design (L9 orthogonal array). Surface roughness (SR) and delamination factor (Fd) were taken as outputs, while spindle speed (SS), feed rate (FR), and drill diameter (DD) were the inputs. Drilling studies were performed on a single vertical machining center (VMC). ANOVA identifies that the FR had the most decisive influence on SR (F=559.24, p=0.001785), followed by DD and SS. FR is the dominant contributor to Fd (F=379, p=0.00263), followed by SS and DD. At low SS and high
Senthilkumar, N.
Investigation of Aluminium Alloy Composites Reinforced with Zirconium oxide and Solid Lubricant Attributes for Brake and Clutch Components of Aircrafts2026-26-07526/1/2026
For brake and clutch components of aircraft vehicles which require higher mechanical strength and wear resilient, light-weight aluminium composites were developed infusing solid lubricant. In this study, hybrid composites were developed using powder metallurgy route with aluminum alloy AA356 and various amounts of zirconium oxide (ZrO2) (0, 5, 10, 15, and 20 wt.%) as reinforcements. A solid lubricant hexagonal boron nitride (hBN) at a fixed 5 wt.% is considered. Following the appropriate ASTM guidelines, the specimens were mechanically characterized by measuring their density, porosity, micro-hardness, compression strength, impact strength, and flexural strength, among other properties. The findings showed that the composites' mechanical and physical behaviour were greatly affected by the inclusion of ZrO2. Porosity increased as a result of particle clustering and interfacial voids, while density increased gradually as ceramic content increased. Consistently increasing ZrO2 addition
Senthilkumar, N.
Wear Resilience Characteristics of Silicon Nitride Strengthened AZ31 Magnesium Composite2026-26-07406/1/2026
To develop magnesium matrix composites, ceramic silicon nitride (Si3N4) particles are added to the magnesium (AZ31) matrix at 2 wt.%. The composite is produced via disintegrated melt deposition vacuum-stir-casting procedure. Microstructural studies reveal the presence of Si3N4 particles and their uniform spreading. An L9 orthogonal array, planned using Taguchi’s experimental design, is selected for three wear parameters; axial load (AL), rotational speed (RS), and time duration (TD) with trials as per the G99 standard in the pin-on-disc apparatus to assess the wear resilient of the composite. Experimental results show an increase in axial stress, and wear loss (WL) increases dramatically. Because the area of contact shrinks as RS increases, WL diminishes dramatically. When the AL is low, the friction coefficient (CoF) increases, and when the AL is large, CoF drops. When the RS is increased, CoF decreases. To optimize multiple responses effectively, the TOPSIS (Technique for Order
Senthilkumar, N., Dhinakar Raj, C K
Hybrid Digital Twin for Aero-Engine Bearing Prognostics: A Physics-Informed Machine Learning Approach to RUL Prediction2026-26-07186/1/2026
Unscheduled maintenance due to the failure of critical components, such as aero-engine rolling element bearings, is a leading cause of costly Aircraft-on-Ground (AOG) events; consequently, current time-based maintenance practices are inefficient and prone to risk. This paper develops a resource-efficient Hybrid Digital Twin (HDT) model for an engine bearing, focusing on the dynamic prediction of spall growth due to Rolling Contact Fatigue (RCF), thereby enabling a condition-based maintenance paradigm. The HDT architecture integrates two core models: (1) a physics-informed model that uses established life and fatigue theory to define initial degradation thresholds, and (2) a data-driven Recurrent Neural Network (RNN), specifically a Long Short-Term Memory (LSTM) network, for dynamic degradation rate modeling. The methodology utilizes a Monte Carlo simulation coupled with RCF progression equations to generate a large, high-fidelity synthetic run-to-failure dataset under varying
Mohamed, Abbas
Porosity Matters: Multiscale Simulation of Composite Panel Performance in Aerospace Structures2026-26-07316/1/2026
Porosity in carbon fibre reinforced polymers (CFRP) remains a critical concern for aerospace engineers, as even minor voids introduced during manufacturing can undermine the reliability of structural components. This work explores the influence of Interply porosity on composite panel behavior, employing a multiscale simulation approach that bridges material characterization and full-scale structural analysis. The study begins with virtual coupon testing using Digimat-VA and Digimat-MF, enabling the prediction of material allowable and the assessment of defect variability. Homogenized material properties derived from these simulations are then applied to detailed panel models constructed in MSC Apex, ensuring accurate representation of layup and orthotropic behavior. The workflow can support a range of structural load cases, allowing for the evaluation of stiffness, buckling, or other relevant scenarios as dictated by aerospace certification requirements. Nonlinear finite element
Savane, Vishal, Kumar, Rajat
Retrofit Vibration Mitigation of Launch Vehicle Structures Using Thin Viscoelastic Coatings: Acoustic and Modal Study2026-26-07366/1/2026
Acoustic-induced vibrations pose a significant risk to launch vehicle hardware and payload reliability during critical phases such as lift-off and transonic phase. Reducing such vibrations is especially challenging when the hardware has already been fabricated, limiting the possibility of structural redesign. This study demonstrates a practical post-fabrication solution using a thin viscoelastic polymer coating applied externally to fully assembled hardware. Comprehensive evaluations were conducted using both acoustic testing and Experimental Modal Analysis (EMA) before and after coating application. During acoustic test, a substantial decrease in structure response from 150Hz to 2000Hz, with a reduction of approximately 50% in the grms values was observed for the coated structure demonstrating significant vibration mitigation over a wide frequency range. In contrast, EMA measurements using impact excitation revealed that the response transfer functions did not show a significant
Avirah, Nohin K, Panda, Ajay Kumar, Shaikh, Altafhusen
Surface Protection Strategies for Dome Shaped Structures against Cavitation Erosion2026-26-07446/1/2026
Submarine-launched missiles with domed nose cones are highly vulnerable to cavitation erosion as they travel at high speed through an underwater launch tube and then into the air from the sea surface. The collapse of vapour cavities crystallizes intense damage on the vehicle surfaces so that the vehicle structure and aerodynamic performance are threatened. In this work, we show the full 3D numerical and analytical analysis of surface protection concepts for the reduction of cavitation damage on such an axisymmetric dome-shaped body. A computational methodology was developed by importing a complex computer-aided design (CAD) model of a dome and the connecting tubular structure into a high-fidelity simulation environment. The geometry was simplified by omitting non-essential details to facilitate the generation of quality mesh for CFD analysis. Simulations have been carried out to analyze the flow field and pressure distribution under two critical stages, at two angles of attack of 0
Velayudhan, Gautham, P S, Premkumar, S, Suhail Ahmed, P, Krishnakumar, Vasantharaj, C
Steel, Corrosion-Resistant, Wire, 18Cr - 9.0Ni (302), Spring TemperAMS5688N (Current)6/1/2026
This specification covers a corrosion-resistant steel in the form of wire.
AMS F Corrosion and Heat Resistant Alloys Committee
Non-Intrusive Fatigue Detection for Pilots2026-26-07936/1/2026
Pilot fatigue represents a critical concern in aviation safety, as it can significantly impair cognitive functions, decision-making abilities, and reaction times. In addition to decreasing performance, in-flight chronic fatigue has negative long-term health effects. Possible causes of fatigue include sleep loss, extended time awake, circadian phase irregularities and workload. Conventionally, the risk due to fatigue in aerospace is reduced by flight time limits and controlled rest requirements. Despite regulations limiting flight time and enabling optimal rostering, fatigue cannot be prevented completely. Hence, there is need to detect pilot fatigue in real time. There is ongoing research to detect pilot fatigue using devices that can capture Electroencephalogram (EEG) and Electrocardiogram (ECG). Though these devices have high fidelity, they are intrusive and can limit pilot activity. This limitation could potentially be overcome by non-intrusive devices such as a smart watch/wrist
Nyamagoudar, Vinayak, P R, Namratha, Ramachandran, Venkataramani
Lightweight Magnesium Nanocomposites with Enhanced Wear Resistance for Landing Gear Application2026-26-07516/1/2026
This study systematically evaluated the wear resilient performance of AZ61 magnesium alloy reinforced with 15 wt.% SiC and diverse amounts of multi-walled carbon nanotubes (MWCNTs) under dry sliding circumstances adopting pin-on-disc apparatus (ASTM G99). To identify the influence of factors like sliding speed (SS) (1-3 m/s), axial load (AL) (10-30 N), and MWCNT concentration (0-3 wt.%) that affect tribological performance, experiments were developed using a Central Composite Design (CCD) under Response Surface Methodology (RSM). SEM micrographs revealed a dispersion optimum near 2 wt.% MWCNT, where CNTs anchor to SiC and bridge the α-Mg matrix, while 3 wt.% shows agglomerates and micro-voids. Findings showed that wear loss (WL) and friction coefficient (CoF) was greatly amplified by increasing AL owing to localized heating and contact stresses. A compacted tribolayer was formed by increasing SS, which decreased WL but marginally raised the CoF. At low AL (10 N), SS (2.09 m/s), and
Senthilkumar, N.
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