Browse Topic: Materials

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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
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 lng, Christelle, Palluel PhD, Marlène, Noiseau lng, Pascal, LARDEUX, Sébastien
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
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
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
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
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
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
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
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
Design-Driven Sustainability of Automotive Components: A Comparative LCA from Conventional to Metal and Composite Additive Manufacturing2026-37-0037To be published on 06/09/2026
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 CNC machining 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 PETG-CF are compared to machined aluminum benchmark. The analysis is integrated in the product and process design following ISO
Dalpadulo, Enrico, Russo, Mario, Apté MD, Raphaëlle, Leali, Francesco
A predictive methodology for 3D-CFD simulation of piston thermal field in sustainable high-performance engines2026-37-0002To be published on 06/09/2026
In recent years, especially in high performance 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 self-ignition can occur. To overcome these problems, one or more jets of oil are directed towards the piston undercrown 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 thermal field. In particular, a 3D-CFD Volume-of-Fluid (VoF) simulation is used to numerically assess the oil jet impact and
Duni, Andrea, Berni, Fabio, Breda, Sebastiano, Fontanesi, Stefano, Gilioli, Filippo
Improvement of rCF behaviour through the introduction of NF2026-37-0039To be published on 06/09/2026
The use of recycled carbon fibres (rCF) allows for reduction of emissions impacting energy and resource requirements. A major drawback of using rCF composites is the discontinuous nature of the fibres as this limits the performance and applications. The present investigation aimed to overcome some of these limitations by manufacturing hybrid composites by combining rCF and natural fibres (NF). One of the key observations was a significant change in the failure mode of hybrid samples under various loading scenarios, where the composite did not shatter but rather failed in a controlled manner. Initial results also showed an overall improvement impact properties in comparison to plain rCF. Similar performance was observed in other tests. Research was focused on determining the most effective ply sequencing under different types of loading and understanding the effect of the ply sequence on the failure mechanisms. It was determined that depending on the application, the layups does effect
Hnatyk, Dawid, Chrysanthou, Andreas, De Vuyst, Tom, Ismail, Sikiru
Augmented Reality and Multimodal Interfaces for Astronaut Training and In-Orbit Operations2026-26-0796To be published on 06/01/2026
Augmented Reality (AR) and multimodal human–machine interfaces (HMI)—combining visual overlays, voice, gesture, eye-tracking, and biometric sensing—are now maturing into flight-relevant technologies capable of transforming astronaut training and in-orbit operations. These interfaces reduce task time, lower error rates, and mitigate cognitive load, thereby strengthening both crew autonomy and mission safety. For India, the timing is critical: Gaganyaan human spaceflight program is approaching decisive crewed missions in the late 2020s, and the Bharatiya Antariksh Station (BAS) is targeted for the 2030s. AR/MMI can be positioned not as an accessory but as a core enabling system for training throughput, real-time crew support, and resilient station operations. This paper provides (i) an overview of India’s current scenario, including Gaganyaan astronaut training ecosystems, IIT Madras collaborations on AR/VR, and Vyommitra humanoid readiness; (ii) synthesis of global case studies—NASA
Yadav, Anoop Singh
Digitalization of Mechanical Labs for Enhanced Traceability and Virtual Verification2026-26-0715To be published on 06/01/2026
Digitalization is the process of leveraging digital technologies to transform business operations, processes, and models, enabling organizations to improve efficiency, create new value, and enhance customer experiences. It is essential as it enables data-driven decisions and reduces product development time. It’s easier to Digitalize new products however, transforming existing products and processes is a challenging task, as constituents are in various phases of lifecycle. Also, the existing/ legacy data acts as a starting point for future programs. Currently, teams are spending hours to weeks finding the right processes and data, costing $~14,000 per test based on labor hours. To tackle this challenge, Mechanical labs are digitalizing their data and processes alongside physical tests via 3DEXPERIENCE application to capture data in digital models and ensure traceability for which Requirement Functional Logical Physical (RFLP) framework is leveraged. This traces Requirements to its
Karpur, Anoop, Inapakolla, Bharat Kumar, Harris, Jason
Investigating the Electrochemical Corrosion Behaviour of Bamboo Fiber-Marine Waste Reinforced Polymer Matrix Hybrid Composites for Light Weight Applications2026-26-0733To be published on 06/01/2026
This study investigates the corrosion behaviour of bamboo-crab shell fortified polymer matrix hybrid composites. Three unique hybrid composites were created utilizing the hand layup approach, with epoxy as the matrix material, 15 wt.% bamboo fibers, and varying quantities (3, 6, and 9 wt. %) of crab shell. Electrochemical corrosion tests were utilized to evaluate the hybrid composite's corrosion behaviour. The testing results reveal that epoxy-15 wt.% bamboo-6 wt.% crab shell (P2) composite has better corrosion resistance than epoxy-15 wt.% bamboo-3 wt.% crab shell (P1) and epoxy-15 wt.% bamboo-9 wt.% crab shell (P3). A potentiodynamic polarization test revealed an icorr value roughly five times lower than P1 and three times lower than P3 composites. Furthermore, the Nyquist plot obtained from the EIS study revealed that the P2 composite has a larger capacity loop than the P1 and P3 composites. It also indicates that the P2 composite is more resistant to corrosion than the other two
Senthilkumar, N., Srinivasan, D, G, Perumal, Balakrishnan, Deepanraj
Evaluating Volume and Hardness change in Fluorocarbon and Ethylene Propylene Rubber Elastomers: Effects of Fluid Aging2026-26-0758To be published on 06/01/2026
Abstract: This research paper investigates the performance of FKM (Fluorocarbon) seal material when exposed to a 50:50 ethylene glycol-water mixture. The study aims to determine the volume change percentage and Hardness change of FKM elastomers under standardized testing conditions. The experimental approach follows ASTM D471 and ASTM 2240 guidelines, focusing on weight and hardness measurements of the test samples to establish a success criterion. The results provide critical insights into the chemical compatibility and durability of FKM elastomers in Aerospace and industrial applications where ethylene glycol-water mixtures are commonly used. The findings contribute to enhanced material selection and design considerations for sealing applications subjected to glycol-based fluids. Samples of FKM material were immersed in the fluid at controlled temperatures and durations, simulating real-world operational conditions. The primary metric of interest, volume change percentage and
Yarolkar, Makrand, Patil, Sandip, Singh, Tanul
Finite Element Approach for Fatigue Life Prediction of Threaded Bolts with Experimental Validation2026-26-0745To be published on 06/01/2026
Predicting the fatigue life of threaded bolts is crucial in aerospace and mechanical assemblies where cyclic loading can cause early joint failure. Previous research conducted experiments to develop S-N curves for high-strength bolts under different pretension and temperature conditions (Zhang et al. 2024). However, there are a very few numerical methods that can replicate these results, especially for bolts with screw threads. In this work a finite element analysis (FEA) methodology is developed to predict the fatigue performance of threaded bolts under axial loading and validated using the experimentally derived Series-1 S-N data for M20 high-strength bolts. The approach includes detailed FEA modelling (3D solid) with explicit thread geometry to capture local stress distributions under cyclic tensile loading. Peak stress amplitudes are employed to estimate fatigue life by applying the Basquin relation and the Series-1 S-N curve. The results are compared with the calculated fatigue
K R, Lesanth, S, Suhail Ahmed, C, Arunvetrivel, P, Krishnakumar, P S, Premkumar, Vasantharaj, C
IMPROVEMENT OF MECHANICAL PROPERTIES OF SYNTHETIC FIBER REINFORCED COMPOSITES THROUGH ADDITION OF GRAPHENE OXIDE2026-26-0753To be published on 06/01/2026
Unmanned Aerial Vehicles (UAVs) demand structural materials that are lightweight, strong, impact-resistant, and durable in diverse environments.The synthetic fiber and natural fiber reinforced polymer composites have varying mechanical performance depending on the fibermatrix interfacial properties. This research analyzes the influence of Graphene Oxide (GO) nano fillers on mechanical properties of composites. Firstly, the epoxy resin was was modified by incorporating different weight percentage of graphene oxide. This resin was used to make an composite laminate using different materials (Carbon, Glass and Natural Fibers). Then the composites were put through the tensile, compression, flexural, and impact strength tests. The synthetic fiber and natural fiber reinforced polymer composites have a significant improvement in mechanical properties due to the addition of graphene oxide.
Manoharan, Dinesh, Langford, Peter, M.K., Padmanabhan, R, Prithviraj, Rajkumar, Subbiah, Karthikeyan, Ravikumar, Veeramuthu, Balasubramaniyan, Gunaseelan, John, T, Thangaraj
Electrical Harnessing in Satellite Launch Vehicles of ISRO – Methods for Sustainable, Safe, and Reliable systems2026-26-0779To be published on 06/01/2026
The electrical harness serves as the "neural network" for satellite launch vehicles, providing the interfaces for all guidance, health monitoring, and control systems during a mission. This system is composed of cables, and connectors. The wires are made of metallic conductors, typically copper plated with silver or gold to enhance conductivity and prevent oxidation. These conductors are insulated with polymeric materials such as PTFE, Kapton, ETFE, or TKT. Connectors, which are the interface points for electrical circuits, consist of gold or nickel-plated copper contacts housed within a shell. A typical launch vehicle contains an extensive network of electrical harnesses, with approximately 4,200 connectors and 110,000 meters of cable, which contributes to about 30% of the vehicle's total weight. The weight is mostly due to the polymeric insulation rather than the conductors. Challenges and Solutions for Sustainable Systems The paper highlights several key issues with current
K S, Nithish, TR, Binny, D S, Praveen Kumar
Mitigation of Assembly-Induced Cracking in Cyclo Olefin Polymer (COP) Optics through Annealing and Step-Torquing Technique2026-26-0764To be published on 06/01/2026
Light Emitting Diode (LEDs) are the main source of light in Aircraft lighting systems and are mounted on a Circuit Board Assembly (CBA). For some applications, Optics are mounted concentric to these LEDs so that light is focused in the required areas. Polymeric optical materials such as Cyclo Olefin Polymer (COP) are adopted as Optics due to their excellent optical clarity, dimensional stability, moldability and weight saving advantages over glass. However, their relatively high notch sensitivity and the presence of residual molding stresses make them prone to crack initiation during mechanical fastening. In this case study, Optic was fastened directly onto the CBA using self-threading fasteners. During its installation, crack formation was consistently observed around self-tapping screw interfaces, raising concerns over reliability, maintainability, and compliance with aerospace durability requirements. A structured Design of Experiments (DOE) was performed to identify root causes and
S, Nikhil, Singh, Abhimanyu Kumar, Katageri, Praveen, SP, Pradeep, Chandra, Praveen
Wear Resilience Characteristics of 2% Silicon Nitride Strengthened AZ31 Magnesium Composite2026-26-0740To be published on 06/01/2026
To develop magnesium matrix composites, ceramic silicon nitride (Si3N4) particles are used to strengthen the magnesium (AZ31) matrix by adding 2 wt.%. The composite is developed by disintegrated melt deposition vacuum stir casting method. Microstructural studies reveal the presence of Si3N4 particles and their uniform distribution. A L9 orthogonal array planned using Taguchi’s experimental design is chosen for three wear parameters axial load (AL), rotational speed (RS), and time duration (TD) for trials as per G99 standard in pin-on-disc apparatus. Experimental outcomes show a rise in axial stress; wear loss increases dramatically. Because the area of contact shrinks as sliding speed increases, wear loss diminishes dramatically. When the AL is low, CoF increases, and when the AL is large, CoF drops. When the sliding speed is increased, CoF decreases. To optimize multiple responses effectively, the TOPSIS method (Technique for Order of Preference by Similarity to Ideal Solution) was
Senthilkumar, N., Dhinakar Raj, C K
Retrofit Vibration Mitigation of Launch Vehicle Structures Using Thin Viscoelastic Coatings: Acoustic and Modal Study2026-26-0736To be published on 06/01/2026
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 PC10 viscoelastic polymer coating applied externally to fully assembled hardware. The PC-10 Thermal Protection System (TPS) is a silicone polymer-based filled compound originally developed by VSSC, ISRO for ablative thermal insulation. Its viscoelastic properties make it suitable for energy dissipation under dynamic loads. Comprehensive evaluations were conducted using both acoustic testing at National Aerospace Laboratories (NAL), Bangalore, and Experimental Modal Analysis (EMA) at ISRO before and after coating application. Results show a substantial decrease in structure response from 150Hz to 2000Hz
Avirah, Nohin K, Panda, Ajay Kumar, Shaikh, Altafhusen
Conceptual design of CFRP sandwich structures interfacing cryogenic tankages in rockets2026-26-0761To be published on 06/01/2026
Interstage and intertank structures of rocket's cryogenic stages face a critical design challenge due to the large thermal contractions in metallic cryogenic tanks after propellant filling. Existing design concepts such as metallic skirts, truss designs, corrugated shells, and special brackets are not mass-efficient. Their direct attachment to cryogenic tanks, combined with the inherently high thermal conductivity of metals, also causes significant heat leakage and necessitates additional thermal insulation. Overall, these configurations result in high mass penalties and reduced efficiency. To overcome these limitations, the present study proposes a Carbon Fiber Reinforced Plastic (CFRP) sandwich composite structure featuring specially designed slits near the tank interfaces. These slits enable controlled deformation and effective stress relief. Furthermore, to minimize the transfer of cryogenic temperatures into adjoining structural regions, thermally insulating Glass Fiber Reinforced
Bhalerao, Sandesh Popat, Gupta, Yogesh Kumar, Madhukumar, P.
Predictive model and analysis of the resultant force in the dry machining of Mg-4Zn/Si3N4 nanocomposites2026-26-0762To be published on 06/01/2026
In aerospace and automotive applications, the usage of magnesium (Mg)-based alloys and composites reduces the structural weight due to their low density. They also possess good specific strength and are abundantly available. The Mg-4Zn alloy is one such Mg-based alloy that is also biodegradable and biocompatible. In spite of these advantages, there is a strong need and scope to improve its wear resistance and mechanical properties. Mg-4Zn nanocomposites with Si3N4 reinforcements (also a biocompatible bio-ceramic) are hypothesized to possess superior properties. Sustainable machining with minimal subsurface defects and minimal energy consumption is necessary to manufacture components from these vacuum stir-cast nanocomposites. The resultant machining force (Fr) is a good indicator of subsurface quality and energy consumption in machining. The addition of Si3N4 reinforcement to improve the properties of the Mg-4Zn alloy could introduce challenges in machining and could influence Fr. To
N, Anand, Shaju, Tony M, G, Nagamalleswara Rao, D, Bijulal, K, Jayaprakash Reddy, K, Vijayan, Chaman, Joji J
Evaluation of Thermal and Thermo-Mechanical Behavior of Ramie Fiber/Delrin Composites for Aircraft Cabin Components2026-26-0754To be published on 06/01/2026
Abstract This study investigates the fabrication and evaluation of Delrin (polyoxymethylene, POM) composites reinforcing 5, 10, 15, and 20 wt.% chopped ramie fiber (RF). The polymer composites were fabricated via injection moulding technique. Glass transition temperature (Tg), thermal conductivity, Vicat softening temperature (VST), heat deflection temperature (HDT), melt flow index (MFI), and coefficient of linear thermal expansion (CLTE) were the various thermo-mechanical and thermal characteristics of the composites that were systematically evaluated as per the ASTM standards. The Delrin matrix's performance was drastically altered by the addition of RF. Within the formulations, the composite with 15 wt.% RF had the best combination of properties: higher VST and HDT values responsible for more dimensional stability at high temperatures, lower CLTE producing lesser thermal expansion, comparatively better thermal conductivity and more heat dissipation. Eventually, there was a moderate
S, Thirumalvalavan, Senthilkumar, N., Selvarasu, S
Assessment of Injection Gate Location effects on Mechanical Performance of Short Fiber Reinforced Plastic Components using Digimat2026-26-0746To be published on 06/01/2026
The mechanical performance of short fiber-reinforced plastic (SFRP) components is highly sensitive to fiber orientation, which is significantly influenced by the injection gate location during the molding process. Traditionally, gate placement decisions are driven by warpage minimization strategies, often overlooking mechanical performance under diverse load cases. This research introduces an automated workflow within Digimat-MS that integrates injection gate optimization into the early design phase, leveraging Integrated Computational Materials Engineering (ICME) principles. The proposed methodology enables engineers to upload either of Marc, Abaqus or Ansys input decks, select a component of interest, assign material cards, and define gate scenarios. A Design of Experiments (DOE) is then executed locally or remotely, allowing Digimat to simulate and evaluate multiple gate configurations. The system aggregates results and identifies optimal gate locations based on the initiation of
Kauthale, Tanmay, Madhavan, Vinay, Soni, Ganesh
Reducing Test Campaigns through Advanced Yield Surface Modeling for New Aircraft Metal Grades2026-26-0755To be published on 06/01/2026
Qualification of new aerospace alloys requires extensive mechanical testing to capture anisotropy and ensure reliable performance under complex loading conditions. This process is costly and time-consuming, particularly with emerging manufacturing routes such as additive manufacturing. Advanced yield surface prediction offers a route to reduce test campaigns by linking microstructural features to macroscopic constitutive models. In this work, Digimat is employed as a multi-scale material modeling platform to generate yield surfaces of polycrystalline metals using computational homogenization. Representative volume elements (RVEs) are constructed from experimental texture and grain morphology data, and their response under multiaxial loading is simulated using a crystal plasticity framework. The computed yield loci are then fitted with phenomenological functions (e.g. Barlat2000), enabling calibration of anisotropic yield models from virtual testing. As a case study, an AA6016-T4 sheet
Padhan, Manas, Uppaluri, Rohith, Lemoine, Guerric, Soni, Ganesh
Development of Graphene filled Polypropylene Nanocomposite for Aerospace Application2026-26-0739To be published on 06/01/2026
Polypropylene, a commodity plastic, is the semi-crystalline thermoplastic widely used in high volume for general purpose applications. Polypropylene is the macro molecules of soft and weak backbone, which by reinforcement of fillers in different forms such as fiber, spheroids, nanotubes, flakes, etc., can influence its mechanical, thermal, electrical, creep resistance, and flame resistance properties for use in aerospace applications. Currently, polycarbonate and nylon plastics are used in aerospace applications, however, they are expensive compared with polypropylene. In this thesis, efforts are put to study the effect of reinforcement fillers in the properties of polypropylene composite, primarily the mechanical and flammability properties. The matrix element, polypropylene co polymer and reprocessed polypropylene blended in equal ratio, are coupled with the dispersing phases such as graphene, mica, fumed silica, and polydimethylsiloxane polymer. Effect of graphene as reinforcing
Govindaraju, Parthasarathy
Non-Intrusive Fatigue Detection and Alerting for Pilots2026-26-0793To be published on 06/01/2026
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, 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 limiting pilot's flying hours and controlled rest requirements. Despite regulations on flying hours and optimal rostering, fatigue cannot be prevented completely. Hence, there is need to detect pilot fatigue in real time, annunciate in cockpit and transmit the information to airliners post-flight for appropriate fatigue risk management. 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
Nyamagoudar, Vinayak, P R, Namratha, Ramachandran, Venkataramani
Porosity Matters: Multiscale Simulation of Composite Panel Performance in Aerospace Structures2026-26-0731To be published on 06/01/2026
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 behaviour, employing a multiscale simulation approach that bridges material characterisation and full-scale structural analysis. The study begins with virtual coupon testing using Digimat-VA and Digimat-MF, enabling the prediction of material allowables and the assessment of defect variability. Homogenised material properties derived from these simulations are then applied to detailed panel models constructed in MSC Apex, ensuring accurate representation of layup and orthotropic behaviour. 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
Investigation of Aluminium Alloy Composites Reinforced with Zirconium oxide and Solid Lubricant Attributes for Brake and Clutch Components of Aircrafts2026-26-0752To be published on 06/01/2026
For brake and clutch components of aircraft, which require higher mechanical strength and wear resistance, lightweight aluminum composites were developed by infusing solid lubricant. In this study, hybrid composites were developed using the powder metallurgy route, using 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' physical and mechanical behaviour were greatly affected by the addition 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.
Drilling Studies on Sustainable Lightweight Hybrid Polymer Matrix High Performance Nanocomposites2026-26-0732To be published on 06/01/2026
Worldwide, engineers are exploring the possibility of using polymer composites in their quest for lightweight materials. In an effort to create polymer composites that are less harmful to the environment, the use of biodegradable polymers has been investigated in recent years. Injection molding was used to create a biodegradable polymer composite containing 20 wt.% vetiver fibers (VFs) and 2 wt.% nano-silica (nSiO2) obtained from pearl millet. Parts for unmanned aerial vehicles, interior cabin panels, seating structures, and secondary structural components were made of this composite. Desirability analysis was used to examine and optimize machining (drilling) studies that were designed according to Taguchi's design (L9 orthogonal array). Surface roughness (Ra) and delamination factor (DF) were taken as outputs, while spindle speed (SS) ranging from 1000 to 3000 rpm, feed rate (FR) from 15 to 45 mm/min, and drill diameter (DD) from 6 to 10 mm were used as inputs. The developed
Senthilkumar, N.
Hybrid Digital Twin for Aero-Engine Bearing Prognostics: A Physics-Informed Machine Learning Approach to RUL Prediction2026-26-0718To be published on 06/01/2026
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 constrain the failure envelope, and (2) a data-driven Recurrent Neural Network (RNN) (specifically, an LSTM) for dynamic degradation rate modeling. The methodology utilizes a Monte Carlo simulation coupled with RCF progression equations to generate a large, synthetic run-to-failure dataset under varying operational loads
Mohamed, Abbas
Thermal Management System in Commercial Aircraft: A Case Study on Passenger Egress System2026-26-0760To be published on 06/01/2026
It is known fact that Thermal management systems are essential to the safety, operational efficiency, and structural integrity of present-day commercial aircraft. Very critical insulation and thermal protection materials are utilized across various aircraft zones to mitigate extreme temperature challenges, ranging from cryogenic conditions at high altitude to pyrotechnic conditions at low altitude/ sea level. Some of the examples where specific materials at their functional role are, • In engine pylons and nacelles, high temperature alloys such as Titanium and Inconel, along with ceramic Matrix composites (CMCs) serve as firewalls and heat shields, which are designed to contain fires and protect primary structures. • In bleed air ducting, fiberglass or silica insulations blankets are employed to prevent thermal degradation of surrounding aluminum and composite components, when air at temperatures above 200 degree C flows. This paper focuses on the critical insulation and thermal
Govindaraju, Parthasarathy, Nanjundegowda, Harshavardhana
Lightweight Magnesium Nanocomposites with Enhanced Wear Resistance for Landing Gear Application2026-26-0751To be published on 06/01/2026
This study systematically evaluated the wear behaviour of an AZ61 magnesium alloy reinforced with 15 wt.% SiC and different amounts of multi-walled carbon nanotubes (MWCNTs) under dry sliding circumstances, adopting a 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.%) on tribological performance, experiments were developed using a Central Composite Design (CCD) under Response Surface Methodology (RSM). Findings showed that wear loss (WL) was greatly amplified by increasing AL owing to localized heating and contact stresses, and that a compacted tribolayer was formed by increasing SS, which decreased WL but marginally raised the coefficient of friction (CoF). At moderate AL (15-20 N), SS (2 m/s), and 2 wt.% MWCNT, the wear resistance was significantly improved by improving load transfer and creating a lubricating carbon-rich coating, resulting in a decreased WL of around
Senthilkumar, N.
Electromagnetic Interference Measurement Antennas; Standard Calibration MethodARP958D (Historical)5/24/2026
This SAE Aerospace Recommended Practice (ARP) outlines a standard method for the checkout and calibration of electromagnetic interference measurement antennas. Its primary application is for use when measuring a source 1 m from the antenna in a shield room versus a source at a greater distance (far field). This is the typical distance used in performing military EMC testing. Thus, this is a method of calibration. Shield room characteristics are not considered. It does not address an unknown distributed source. Yet it is close to reality since it is based on another antenna that represents a distributed source. This document presents a technique to determine antenna factors for antennas used primarily in performing measurements in accordance with 2.1 and 2.2. The purpose of Revision B is to include the calibration of other antennas, such as small loop antennas that are also specified for use in these same references. Revision D includes a specific procedure for loop antennas that are
AE-4 Electromagnetic Compatibility (EMC) Committee
ELECTROMAGNETIC COMPATIBILITY MEASUREMENT PROCEDURE FOR VEHICLE COMPONENTS—PART 22—IMMUNITY TO RADIATED MAGNETIC FIELDS FROM POWER LINESJ1113/22_199610 (Current)5/24/2026
This SAE Standard covers the recommended testing technique for determining the immunity of automotive electronic devices to magnetic fields generated by power transmission lines and generating stations.
Electromagnetic Compatibility (EMC) Standards
SNOWMOBILE AND SNOWMOBILE CUTTER LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENTJ292_199505 (Current)5/23/2026
This SAE Recommended Practice describes requirements for lamps, reflective devices, and associated equipment for signaling to enable safe operation in darkness and other conditions of reduced visibility.
Snowmobile Technical Committee
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Part 13: Immunity to Electrostatic DischargeJ1113/13_201106 (Current)5/23/2026
This SAE Standard specifies the test methods and procedures necessary to evaluate electrical components intended for automotive use to the threat of Electrostatic Discharges (ESDs). It describes test procedures for evaluating electrical components on the bench in the powered mode and for the packaging and handling non-powered mode. A procedure for calibrating the simulator that is used for electrostatic discharges is given in Appendix A. An example of how to calculate the RC Time Constant is given in Appendix B Functional Performance Status Classifications for immunity to ESD and Sensitivity classifications for ESD sensitive devices are given in Appendix C.
Electromagnetic Compatibility (EMC) Standards
Measurement of Radiated Emissions from Integrated Circuits—Surface Scan Method (Loop Probe Method) 10 MHz to 3 GHzJ1752/2_201609 (Current)5/23/2026
This SAE Recommended Practice defines a method for evaluating the near field electric or magnetic component of the electromagnetic field at the surface of an integrated circuit (IC). This technique is capable of providing a detailed pattern of the RF sources internal to the IC. The resolution of the pattern is determined by the characteristics of the probes used and the precision of the mechanical probe positioner. The method is usable over the 10 MHz to 3 GHz frequency range with existing probe technology. The probe is mechanically scanned according to a programmed pattern in a plane parallel or perpendicular to the IC surface and the data is computer processed to provide a color-enhanced representation of field strength at the scan frequency. This procedure is applicable to measurements from an IC mounted on any circuit board that is accessible to the scan probe. For comparisons, the standardized test board shall be used. This diagnostic procedure is intended for IC architectural
Electromagnetic Compatibility (EMC) Standards
Characterization, Conducted ImmunityJ2628_201806 (Historical)5/23/2026
The methods included in this document are: a Voltage-Temperature Design Margins. b Voltage Interruptions and Transients. c Voltage Dropouts and Dips. d Current Draw Under a Number of Conditions. e Switch Input Noise These methods are best applied during the Development stage but can be used at all stages (e.g., Pre-Qualification, Qualification or Conformity).
Electromagnetic Compatibility (EMC) Standards
Motorcycle Stop Lamp SwitchJ1167_201401 (Current)5/23/2026
This SAE Recommended Practice defines the test conditions, procedures, and performance specifications for 6- and 12-v stop lamp switches intended for use on motorcycles.
Motorcycle Technical Steering Committee
Vehicle Electromagnetic Immunity – Power Line Magnetic FieldsJ551/17_200305 (Historical)5/22/2026
This SAE Standard specifies the test methods and procedures for testing passenger cars and commercial vehicles to magnetic fields generated by power transmission lines and generating stations.
Electromagnetic Compatibility (EMC) Standards
Snowmobile Tail Lamp (Rear Position Lamp)J279_201103 (Current)5/22/2026
This SAE document provides test methods and requirements for tail lamps for snowmobiles.
Snowmobile Technical Committee
Vehicle Electromagnetic Immunity - Power Line Magnetic FieldsJ551/17_201507 (Current)5/22/2026
This SAE Standard specifies the test methods and procedures for testing passenger cars and commercial vehicles to magnetic fields generated by power transmission lines and generating stations. SAE J551-1 specifies general information, definitions, practical use, and basic principles of the test procedure.
Electromagnetic Compatibility (EMC) Standards
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Part 13: Immunity to Electrostatic DischargeJ1113/13_201502 (Historical)5/22/2026
This SAE Standard specifies the test methods and procedures necessary to evaluate electrical components intended for automotive use to the threat of Electrostatic Discharges (ESDs). It describes test procedures for evaluating electrical components on the bench in the powered mode and for the packaging and handling non-powered mode. A procedure for calibrating the simulator that is used for electrostatic discharges is given in Appendix A. An example of how to calculate the RC Time Constant is given in Appendix B Functional Performance Status Classifications for immunity to ESD and Sensitivity classifications for ESD sensitive devices are given in Appendix C.
Electromagnetic Compatibility (EMC) Standards
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