Browse Topic: Analysis methodologies

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High-frequency mount characterization: a comparison of methodologies2026-01-0693To be published on 06/20/2026
The rapid electrification of the automotive industry introduces new challenges in noise, vibration, and harshness (NVH). In particular, in a virtual prototyping phase of the e-vehicles development, the rubber mounts are often one of the key elements to be considered when analysing the structure borne noise contributions. Having an accurate experimental characterization of the mount dynamic stiffness curves is therefore very relevant. However, conventional mount characterization methods are often pushed to their limits, partly due to the use of stiffer bushings, and partly because the frequency range of interest is extended toward higher frequencies. When using inverse substructuring, the dynamic stiffness curves can be obtained from frequency response function measurements. The required test setup consists of excitations and responses, located on each side of the mount via dedicated fixtures. The measured frequency response functions are reduced into 6 degrees of freedom representation
Bianciardi, Fabio, Forrier, Bart, Minervini, Domenico, Barbieri, Marco, Janssens, Karl
Spatial Noise Acquisition at the Driver's Position in an Electric Vehicle with Increased Accuracy2026-01-0723To be published on 06/20/2026
In vehicles with electrified powertrains, high-frequency tonal noise components have become increasingly prominent and can be perceived as particularly annoying by the driver. While recent advancements in international standardization—such as ECMA-74 and ECMA-418—have led to powerful new algorithms for tonal noise visualization and analysis, like our Tonality-Heatmaps, the measurement side still lacks sensor setups that adequately reflect the spatial sensitivity of noise, especially for tonal components. This challenge is amplified in enclosed vehicle cabins, where room modes create local minima and maxima that become increasingly dense at higher frequencies. As a result, even small head movements can lead to noticeable differences in perceived tonal noise. Current measurement approaches do not sufficiently account for this spatial variability. This contribution addresses the absence of tailored solutions for the driver’s position by introducing an improved microphone arrangement that
Schecker, Daniel, Rittenschober, Thomas
Methodology Development for EDM Vibro-acoustic Assessment using Simulation Measurement Comparison and RCA2026-01-0691To be published on 06/20/2026
The virtual development of Electric Drive Modules (EDM) for Battery Electric Vehicles (BEVs) requires proven and predictive methodologies. One part of the development investigates the vibro-acoustic assessment for low and high frequencies over the targeted operating range. The efficient usage of such a methodology requires the understanding of the accuracy and the validity of the achievable results as well as the derivation of suitable improvement measures for goals that have not been achieved. The usage of reference data from experimental investigations and a detailed root-cause analysis (RCA), to directly link a specific response and behavior to the excitations, modal content and transfer functions, is an essential and non-trivial part of the methodology development. This paper describes the development of such a methodology using the example of a new EDM virtual model for Noise, Vibration and Harshness (NVH) analysis, the simulation approach, validation, and evaluation procedure. It
Klarin, Borislav, Pevec, Denis, Resch, Thomas, Esposito, Sara, D'Alessandro, Vincenzo, Spanu, Giorgio
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
Feasibility of Hybrid Dynamic Substructuring for Structural Modifications in Automotive Suspension Subsystems2026-01-0697To be published on 06/20/2026
Recent advancements in system-level NVH (Noise, Vibration, and Harshness) development methodologies have improved target cascading and enabled more efficient system-level optimization. Dynamic substructuring facilitates the virtual integration and modification of multiple subsystems and the prediction of changes in overall transfer functions. In practical automotive applications, advanced frequency-based substructuring has been applied to virtually modify system parameters—such as mass and stiffness—at multiple points in a target system, allowing prediction of the resulting effects and optimization of parameter changes without physical intervention. This study extends the methodology by introducing an enhanced substructuring approach capable of addressing not only basic parameter modifications but also large-scale structural changes. The proposed process involves identifying the characteristics of a base system assembly and a target subsystem, decoupling the subsystem from the assembly
Cho, Munhwan, Boelens, Jelle, Reichart, Ron, de Klerk, Dennis, Ahn, Jiho
Mid-High frequency structure-borne transmission in full vehicles trimmed body models using a reverberant finite element approach2026-01-0706To be published on 06/20/2026
The simulation of structure-borne energy flow within a full vehicle trimmed body at mid and high frequencies has always been a challenge due to the large computational cost associated with standard deterministic simulations. This is a particularly pressing problem given that the electrification of the vehicles is extending the presence of structure-borne sources to higher frequencies. While the improvement of computational hardware has allowed OEMs to shift the limit of standard Finite Element (FE) approaches to higher frequencies, no methods have been proposed in the literature that tackle the full frequency range for industrial-sized problems. In this paper, a simulation methodology that uses wave-based processing of the original low-frequency finite element input deck to compute the coupling loss factors is proposed to model structure-borne noise in complex systems at mid and high frequencies. The methodology is validated against numerical and experimental data.
Errico, Fabrizio, Legault PhD, Julien, Mordillat, Philippe, Zerrad, Mehdi
Simulation and Analysis of Flow and Acoustic Induced Structural Vibration2026-01-0696To be published on 06/20/2026
For analysing flow and acoustic induced structural vibration, a run time fully coupled framework combining a hybrid CFD-CAA approach with a modal response simulation was validated and presented at the ISVNH 2022 (SAE Technical Paper 2022-01-0938). In this contribution we show the application of this method on a production vehicle, simulating the flow and acoustic induced vibration of the bonnet. The simulation setup of this study resolves the geometry of the vehicle including the complex details of the bonnet structure, the frunk and the engine compartment. The FEM model for the modal analysis of the bonnet takes into account the complex boundary conditions at the bearings and provides the eigenmodes relevant for the low frequency range. Simulations are conducted in an undisturbed wind tunnel setup and the resulting vibrations are compared to acceleration measurements under wind tunnel and road conditions. Due to the employed hydrodynamic acoustic split approach, the relevance of the
Schwertfirm, Florian, Ocker, Joerg, Hartmann, Michael
AI-Based Package Tray Design Method for Controlling Acoustic Modes in a Sedan2026-01-0716To be published on 06/20/2026
• In this study, we propose a methodology for predicting the acoustic modes and natural frequencies of a sedan using artificial intelligence and demonstrate the feasibility of controlling its acoustic characteristics by modifying the hole distribution of the package tray. In typical sedan structures, the cabin cavity and trunk cavity are acoustically coupled through holes in the package tray. The distribution of these holes significantly affects the natural acoustic modes and frequencies of the vehicle. However, once the exterior shape of the vehicle is finalized during the design phase, options for structural modifications to mitigate noise issues caused by these modes become extremely limited. To address this challenge efficiently, we develop a deep learning-based neural network model trained on data derived from a simplified acoustic analysis model of a sedan that includes a package tray. Finite element analysis is performed to generate acoustic modes and natural frequencies, which
Lee, Jin Woo, Cho, Jaeho, Nam, Younsic, Han, Yongha
Robustness Analysis for A Computationally efficient Virtual Sensing Framework in time-domain for Exterior Vibroacoustics problems2026-01-0721To be published on 06/20/2026
Reconstruction of acoustic radiation from vibrating structures is central in vibroacoustic, as full-field sound information is essential for identifying radiation mechanisms and improving structural-acoustic performance. Conventional microphone-based measurements are limited by spatial sampling constraints and high experimental cost, while purely numerical approaches such as Finite Element Method (FEM) simulations, particularly in the frequency domain, offer flexibility but are strongly affected by parameter uncertainties, discretization errors, and imperfect boundary conditions. To overcome these drawbacks, this work develops a hybrid time-domain framework that couples vibration measurements with FEM-based acoustic models. The FEM model is reduced using Krylov subspace projection, yielding a compact state-space representation that captures the dominant vibroacoustic modes while remaining computationally efficient for sequential data assimilation. The acoustic radiation domain is
Dong, Luyao, Cai, Yinshan, Denayer, Hervé, Deckers, Elke
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
Frequency Based Substructuring as Key Enabler for New NVH Root Cause Analysis Types in FE Simulations2026-01-0710To be published on 06/20/2026
Noise, vibration, and harshness (NVH) performance is critical in the automotive development process, yet identifying the true root causes of unwanted dynamic behavior remains a challenge in full vehicle or system‑level finite element (FEM) models. This work demonstrates how frequency based substructuring (FBS) provides an efficient framework for understanding NVH and facilitates new root cause analysis types and processes. To begin, we prove the high numerical accuracy of the FBS algorithm deployed in the BETA CAE software by comparing its results with those obtained without substructuring. Then we illustrate how FBS supports new root cause analysis types, starting with a new variant of transfer path analysis (TPA). While standard TPA assesses the paths between only two system components, the new expanding TPA is a multi-step process that identifies the most critical path across all components in a fully automated way. Furthermore, if the FBS workflow starts with a modal representation
Herbst, Markus
A High-Performance Computing Strategy for Acoustic Encapsulation Modeling of Electric Vehicle Subsystems Using Coupled BEM–PEM–FEM Methods2026-01-0694To be published on 06/20/2026
Electric vehicle subsystems, including powertrains, electric motors, and gearboxes, pose new challenges in achieving stringent acoustic performance targets for both interior and exterior noise. These challenges are intensified by increasingly demanding customer expectations regarding interior acoustic comfort, which encompasses the reduction of intrusive noise sources and the enhancement of overall sound quality across a broad frequency spectrum. A primary concern associated with electric vehicles subsystems is the generation of high-frequency tonal noise, commonly referred to as whine noise, which can significantly impact acoustic performance and passenger comfort. High-frequency whine noise propagates through multiple transmission paths and can be effectively attenuated at the source through encapsulation strategies, which also contribute to broadband noise reduction across a wide frequency spectrum. To predict the acoustic performance of encapsulation, a coupled simulation approach
Amichi, Kamel, Calloni, Massimiliano
Early-Stage BIW Design Evaluation Using Higher-Order Beam–Shell Hybrid Models2026-01-0674To be published on 06/20/2026
Achieving favorable NVH and durability performance in the vehicle requires sufficient static and dynamic stiffness of the Body-in-White (BIW). Virtual development of BIW performance targets in the early stages is essential to minimizing costly modifications in later phases. In the automotive industry, full-scale finite element models are widely used for this purpose, offering high fidelity and enabling virtual performance evaluation. However, their complexity and the significant computational resources they demand limit their practicality for early-stage sensitivity and optimization studies. Beam-based models offer a faster alternative, but conventional formulations based on Euler or Timoshenko theory often fail to capture the complex deformation behaviors of thin-walled structures typical of BIW designs. This limitation generally leads to poor correlation with detailed models unless artificial joint flexibility is introduced. To address these challenges, we propose a hybrid modeling
Kim, Jin Hong, Gang-Won, Jang
NEW CORRELATION APPROACH FOR BODY DISTORTION OF A COMPLETE VEHICLE USING MBD AND TEST RESULTS2026-01-0680To be published on 06/20/2026
By using a fully trimmed vehicle body as flexible body (MNF model) in a complete vehicle Multibody Dynamics (MBD) analysis, the simulation setup gets considerably closer to the test conditions compared to only using a linear FEM approach. Since the MBD analysis includes the nonlinear behavior of the wheel suspension, the gravity and the rigid body modes of the vehicle, it brings the correlation between simulation and test to a new and more comprehensive level. As correlation criteria, the results of the so-called Multi Stethoscope (MSS) are used. The MSS captures the time history of distortion in all body openings and cross sections and enables a detailed stiffness evaluation of the body using the so-called Opening Distortion Fingerprint (ODF). The ODF gives the quasi-static response while the Operational Deflection Shape (ODS), which is another result of the MSS measurements, reflects the dynamic response. Apart from the different individual steps of this new correlation approach, the
Lindkvist, Lisa, Olger, Emma, Piiroinen, Petri, Karypidis, John, Pena, Milton, Bäcklund, Jesper, Appelgren, Peter, Marberg, Henrik, Ugale, Pravin, Weber, Jens
Development of a Convolutional Autoencoder-Based Unsupervised Classification and Visualization Model for Extracting Feature Frequency in C-EPS Fault Diagnosis2026-01-0717To be published on 06/20/2026
In the automotive industry, deep learning models such as convolutional neural networks, autoencoders, and transformers have been actively studied to improve defect detection rates in End-of-Line (EOL) processes. However, applying these approaches to the field of Noise, Vibration, and Harshness (NVH) faces several practical challenges. ① Difficulty in securing sufficient training data and risk of overfitting due to longer evaluation times compared to other data types. ② Label imbalance caused by the relatively small amount of defective data. ③ Reduced labeling accuracy due to human error. ④ Decreased model robustness under domain shifts such as jig variations, evaluation environments, signal-to-noise ratio (SNR), and the occurrence of new abnormal noises. ⑤ Constraints in application due to compatibility issues with existing evaluation equipment. To address these issues, this study proposes an unsupervised learning-based method for classifying operating noise data of Column-type
Park, Jun-Seo, Jo, Hyeon-Choel, Cho, In-Je, Seo, Jae-Yong, Yoo, Seong-Sik
Transmission Loss of Vehicle Components Using Virtual SEA: Validation and Modeling Challenges2026-01-0705To be published on 06/20/2026
In the automotive industry, controlling noise transmission through vehicle components is essential for passenger comfort and regulatory compliance. Traditionally, Transmission Loss (TL) is estimated using simplified CAD-based metrics, which lack accuracy at high frequencies and for complex assemblies. This study presents an industrial application applying the Virtual SEA (Statistical Energy Analysis) method to evaluate TL for firewall. Modeling complex vehicle components introduces challenges, such as representing fluid-structure and trim interactions, with spatially varying trim thicknesses. The study discusses strategies for subsystem adaptation and analytical trim modeling, highlighting the importance of managing untrimmed zones and spatial averaging effects. The proposed workflow integrates laboratory measurements of trim materials, advanced subsystem definition, diffuse sound field excitation and radiation in free conditions. Virtual SEA results are systematically validated
Orselli, Joseph, Jacquemin, Gaetan
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
Optimization of a Halbach array for torque ripple reduction in a Yokeless And Segmented Armature axial flux machine2026-01-0754To be published on 06/01/2026
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
THERMO-STRUCTURAL ANALYSIS OF GRID FINS FOR RE-ENTRY MODULES2026-26-0749To be published on 06/01/2026
Grid fins are lattice structures employed as aerodynamic control surfaces to achieve the required static stability of re-entry modules during atmospheric descent. Grid fins help to stabilize the re-entry modules by counteracting aerodynamic instabilities, especially when the module is moving through the atmosphere at high speeds. Each panel within the grid fin functions as an individual fin, generating lift and drag forces that enhances the overall stability of the re-entry module. In contrast to conventional fins, grid fins incorporate a distinctive waffle-like pattern or grid pattern configuration, offering superior aerodynamic performance in supersonic regimes and enabling compact storage through folding during launch followed by deployment at the time of exigency. The separation of re-entry modules from their launch vehicles is typically executed using high-thrust, fast-acting solid rocket motors (SRMs) which provide the impulsive force needed for clean detachment. The primary
Mali, Somanath Nandu, Sundar Raj, R, Sundaresan, MK, R, Suresh
Integrating Human Factors and Predictive Modeling for Enhanced Aviation Safety: A Data-Driven Approach to Risk Mitigation and System Design2026-26-0795To be published on 06/01/2026
The evolution of the aviation industry from manual control to highly automated and autonomous systems has brought human factors to the forefront of safety, design, and operational efficiency. This paper presents an integrated analysis combining machine learning techniques with statistical modeling to assess the impact of human-system interaction on aviation incident outcomes. The first phase of this research involved a longitudinal dataset covering aircraft design evolution, training programs, and incident records. Using classification algorithms, including XGBoost, the study achieved an accuracy of 81.82% in predicting incident likelihood. Performance metrics such as F1-scores (0.85 for “Incident” and 0.78 for “No Incident”) highlighted the model’s robustness in identifying risk patterns associated with human factors and system complexity. In the second phase, 50 plus detailed aviation incident reports were analyzed using logistic regression, t-tests, and Cook’s Distance to identify
Valiyaparambil, Praveen
Key Modeling Considerations for Reliable FEM-Based Demagnetization Evaluation of IPMSM2026-01-0741To be published on 06/01/2026
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
Dynamic Wireless Charging for Electric Vehicles2026-01-0748To be published on 06/01/2026
This paper investigates the electromagnetic and circuit-level performance of an inductive power transfer (IPT) system for dynamic wireless charging of electric vehicles (EVs). Key design parameters affecting power transfer efficiency (PTE) are explored. A simplified Series-Series (SS) compensated IPT model using Double-D coil geometry and shielded ferrite backing was developed using MATLAB software. The framework has been built around variations of air gap, lateral misalignment, load resistance, and operating frequency. The results show that PTE is highly sensitive to spatial alignment, with a significant efficiency loss at air gaps greater than 10 cm and misalignments beyond 15 cm. Both parameters can cause a compounded nonlinear effect on the PTE, thus a 3D surface plot was used to confirm the simultaneous effects of both parameters. Load resistance analysis revealed an optimal range around 10–15 Ω, while frequency analysis showed a peak efficiency near 85 kHz, in alignment with SAE
Abdelrahman lng, Marwan, Sodre, Jose Ricardo
Numerical Analysis of Pre-Ignition Factors in Hydrogen Engines2026-01-0740To be published on 06/01/2026
Numerical analysis was conducted to investigate abnormal combustion, a major challenge in efforts to improve hydrogen engine efficiency. Focusing on two factors that induce abnormal combustion—surface reactions and lubricating oil—numerical analysis examined the potential for each to trigger abnormal combustion. Furthermore, since it was confirmed that the self-ignition prediction using a detailed chemical reaction mechanism deviates from experiments at temperatures around 800K, attempts were made to improve this issue. As a result, it was confirmed that surface reactions affect the chemical species ratio near the wall surface but have little effect on flame propagation. Regarding lubricating oil, two possibilities were investigated: the lubricating oil itself self-igniting and becoming an ignition source for the hydrogen mixture, and deposits generated from the lubricating oil generating heat and becoming an ignition source. We investigated two possibilities: the lubricating oil
Moriyoshi, Yasuo, Yamane, Taichi, Wang, Zhiyuan, Kuboyama, Tatsuya
Identifying and mitigating resonance effects in HV Powernets2026-01-0742To be published on 06/01/2026
HV Power nets of electric vehicles consists of various HV components such as batteries, inverters, auxiliaries and cables. During in-vehicle testing, multiple failures of an auxiliary inverter were observed, caused by resonance issues within the component filter. Initial investigations revealed that these resonances, absent during manufacturer testbench evaluations, were influenced by the vehicle power net and its impedance characteristics. To better understand the underlying causes and identify preventative measures, extensive simulations were performed. The results demonstrate a diminishing influence of the power net capacitance when significantly larger than the component capacitance. Also they highlight the critical impact of cable inductance on the component resonance frequency when comparable to the component’s inductance. A simplified electrical equivalent circuit was used to derive an equation predicting the resonance frequency as a function of the component’s capacitance
Schmiel, Fabian, Aurand PhD, Tobias, Koehnlechner, Benjamin, Zimmer PhD, Markus
Investigation of Acoustic Fill Effect of a Launch Vehicle Payload Fairing2026-26-0759To be published on 06/01/2026
The payload fairing of a launch vehicle is subjected to extremely high acoustic loads, with peak levels occurring during lift-off and transonic aerodynamic regimes. The external acoustic field penetrates the fairing, producing intense internal sound pressure levels that can challenge the integrity of spacecraft components. Accurate characterization of the vibroacoustic behaviour of the payload fairing and its enclosed cavity is therefore essential to ensure spacecraft survivability. The internal acoustic field is governed by the coupled dynamics of the fairing structure and the spacecraft configuration, making it critical to quantify the acoustic environment for different payload arrangements. This study presents a detailed vibroacoustic analysis of a payload fairing with multiple spacecraft configurations to evaluate the resulting internal sound pressure distribution. Vibroacoustic finite element analysis (FEA) is employed in the low frequency range, while statistical energy analysis
S R, Arun Raj, Jayan, Mahind, George, P
Sensitivity Analysis of Geometric Imperfections in Aerospace structures2026-26-0738To be published on 06/01/2026
Launch vehicle structures are designed to withstand flight loads ensuring design adequacy after thorough structural assessment. In general, Preliminary FE model assumes perfect geometry of structures for analysis without considering profile imperfections arising during course of fabrication. These deviations, occurring during manufacturing, can significantly reduce the structure's load capacity. Traditional analysis often relies on simplified or theoretical imperfection models, which are different from "fabricated" hardware, leading to either underestimation or over estimation of margin for structural design loads. This paper presents a robust methodology for a cylindrical structure by directly incorporating measured manufacturing deviations into the finite element (FE) model. Thin-walled cylindrical structures, particularly those with complex stiffening patterns like isogrid panels, are sensitive to geometric imperfections. The subject hardware exhibited significant non-conformances
Sharma, Amit, Singh, Nishant, Xavier, Shijo, R, Suresh
Automated Flight Maneuver Recognition for Intelligent Flight Simulator2026-26-0713To be published on 06/01/2026
The rapid growth in the number of aircrafts and pilots emphasizes the need for an AI-enabled training framework that can offer precise, automated examination of flight maneuvers, thereby optimizing the pilot’s training efficiency and minimizing iterations of the conduct of flight maneuvers thereby reducing the training time of the pilot for a flight. This paper introduces a novel hybrid methodology to intelligently detect manoeuvres performed during a flight using signal processing and machine learning techniques. A general framework is developed that can be used for all kinds of flight phases and aircraft types. The framework is implemented in a two-step approach. Firstly, Continuous Wavelet Transform (CWT) of the signals of interest for different manoeuvres are generated, to find the time at which a manoeuvre happens during a sortie. CWT looks at the energy levels in the transformed signal and uses smart thresholding technique to pick out only the parts with high energy, to extract
Sahu, Akash, C, Poornima, C, Aravindh, Kaliyari, Dushyant, TK, Khadeeja Nusrath
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
Hybrid Physics-Informed Neural Network and PID Control for Fault-Tolerant Autonomous Multi-copters2026-26-0770To be published on 06/01/2026
This paper addresses the critical challenge of fault-tolerant control in autonomous multi-copters, particularly under conditions of one or two rotor failures a scenario that often leads to severe instability and a complete loss of directional control due to unbalanced torque and resultant autorotation. Existing advanced control strategies, including optimal approaches such as LQR, typically require precise system modeling and state estimation, which are difficult to achieve in real-world, dynamic failure scenarios. Alternative methods like fuzzy logic, sliding mode control, and gain-scheduling either lack robust generalization or are impractical for enumerating all possible failure cases. In this work, a hybrid control framework integrating Physics Informed Neural Networks (PINN) with a standard PID controller is proposed for fault-tolerant operation of autonomous multi-copters subject to multiple actuator failures. PINNs incorporate governing physical laws as regularization in their
Charapalle, Samruddhi, Venugopalan, Nandagopalan, Nerkundram Muralidharan, Arun, Sundararaj, Laveen
Influence of Boundary Conditions on Dynamic Characterization of Launch Vehicle Structures with Closely Spaced Modes2026-26-0730To be published on 06/01/2026
Dynamic characterization tests play a critical role in launch vehicle applications, as they provide the frequencies and mode shapes required for refining Finite Element Models (FEM) and ensuring structural integrity. While such tests are often routine when mode shapes in orthogonal planes are well separated, practical challenges arise when modes are closely spaced. In these cases, careful test planning and execution become essential to obtain reliable results. A key factor influencing test outcomes is the boundary condition of the test article. Although free-free suspension, achieved through very low-frequency support, is theoretically ideal, it is often impractical. As a result, most dynamic characterization tests are performed with a base-fixed condition, where the properties of the supporting structure can influence the measured response. For structures with asymmetry limited to a single axis, mode shapes are typically expected to align along that axis; however, deviations may occur
Panda, Ajay Kumar, Avirah, Nohin K, Shaikh, Altafhusen
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
An Integrated Digital Engineering Framework for Parametric Design and Finite Element Analysis of Aerospace Systems2026-26-0735To be published on 06/01/2026
Digital engineering initiatives in aerospace demand more than conventional finite element analyses; they require integrated, traceable, and systematic workflows that shorten iteration cycles, enable rapid trade-off studies, and ensure verification across the design process. FEAST (Finite Element Analysis of Structures)—an indigenous finite element software developed by VSSC, ISRO—provides structural analysis capabilities, but its native command structure is not directly compatible with automated, iterative design exploration. This limitation creates a gap between solver functionality and the needs of modern model-based engineering, where efficiency, reproducibility, and scalability are critical. To address this gap, a unified workflow is proposed that links parametric geometry modeling, load-case management, solver execution, and results visualization in a seamless manner. The framework automates repetitive pre- and post-processing tasks, enables systematic evaluation of alternative
Gupta, Shivangi, T J, Raj Thilak, P, Deepak
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
Novel material architecture for enhanced high cycle fatigue life in turbofan engine fan blades2026-26-0748To be published on 06/01/2026
High Cycle Fatigue (HCF) is a critical failure mode in turbofan blades, primarily driven by resonance phenomena when the blade’s natural frequency aligns with engine-induced excitations. Traditional approaches to mitigate HCF often involve geometric modifications or damping treatments, which can adversely affect aerodynamic performance or increase component weight. This study explores alternative methodologies to strategically alter the natural frequency of turbofan blades while maintaining aerodynamic efficiency and structural integrity. A novel material architecture is proposed, consisting of a dual-metallic configuration with a high-stiffness core and a lightweight, fatigue-resistant outer shell. This design enables precise tuning of the blade’s dynamic response by leveraging the contrasting mechanical properties of the core and outer materials. The dual-metallic structure shifts the natural frequency away from critical excitation zones, thereby reducing the risk of resonance
S, Ravivarman, Inamdar, Prachi, De, Rohit
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
Design and Multi-Faceted Validation of UAV Arm Clamps, Landing Gear and Motor Mounts via Generative Design in Autodesk Fusion 3602026-26-0734To be published on 06/01/2026
The reliability of the entire airframe is essential for Unmanned Aerial Vehicles (UAVs) deployed in critical surveillance and disaster management missions. Performance cannot be compromised, as even minor structural weaknesses can impact flight stability and mission success. This work introduces a thorough "design–simulate–build–test" process that combines advanced simulation, additive manufacturing, AI-driven generative design, and experimental validation to construct an assembly of high-performance UAV structural components. Motor mounts, arm clamps and landing gear were among the important structural components of a custom UAV that were redesigned using the suggested technique. With the use of Autodesk Fusion 360's generative design tools, every component was tailored for Fused Filament Fabrication (FFF) additive manufacturing. Their mechanical performance was first predicted through a detailed Finite Element Analysis (FEA) framework. To experimentally validate these simulations
Krishna Bansal, Vaibhav
Estimation of dynamic responses at internal points of a nested sub-structure with two-level Craig-Bampton reduction2026-26-0747To be published on 06/01/2026
Dynamic analyses of large and complex structural assemblies usually employ sub-structure coupling or Component Mode Synthesis (CMS) methods. The most widely used CMS method for dynamic analyses is the Craig-Bampton (CB) method. The displacement transformation of the CB method employs fixed-interface normal modes and interface constraint modes as the component modes. Dynamic analyses utilizing Craig-Bampton-reduced sub-structure matrices will provide information about dynamic responses at interface degrees-of-freedom (DOFs) and at generalized DOFs corresponding to fixed interface normal modes. However, physical responses at internal DOFs cannot be obtained directly from these analyses. In order to extract dynamic responses at selected internal DOFs, Output Transformation Matrices, which define a relation between responses at component modes and at internal DOFs, are used. In this paper, an approach to estimate and validate the internal point dynamic responses in a nested sub-structure
Ramachandran, Nirmal
Effect of Fluid Flow/Time Duration on Static Voltage Generation for Aerospace Hose Assembly2026-26-0757To be published on 06/01/2026
Static electricity is an electrical imbalance on the surface of a material that can interact with other components made of the same or different materials. Fluid (hydrocarbons) flow within the hose assembly generates static voltage due to the friction caused by fluid flow in pipes, which needs to be appropriately quantified and dissipated. Accumulation of such static charge may lead to sudden discharge, resulting in spark generation. Spark generation around fuel flow might lead to system failure and failure in aircraft engines. Experiments were conducted to analyze the static voltage generated in the hose assembly with a fixed hose assembly length due to fuel flow, with the objective of achieving acceptable voltage levels to avoid ESD (electrostatic discharge) failure. The procedure includes fuel flow rate monitoring and voltage measurement. The testing revealed that the curvature of the hose affects the readings, highlighting the importance of consistent meter alignment. Using a
Waghmare, Shashank
Potential Failure Mode and Effects Analysis (FMEA) Including Design FMEA, Supplemental FMEA-MSR, and Process FMEAJ1739_202605 (Current)5/7/2026
This FMEA standard describes potential failure mode and effects analysis in design (DFMEA), supplemental FMEA-MSR, and potential failure mode and effects analysis in manufacturing and assembly processes (PFMEA). It assists users in the identification and mitigation of risk by providing appropriate terms, requirements, rating charts, and worksheets. As a standard, this document contains requirements—”must”—and recommendations—”should”—to guide the user through the FMEA process. The FMEA process and documentation must comply with this standard as well as any corporate policy concerning this standard. Documented rationale and agreement with the customer are necessary for deviations in order to justify new work or changed methods during customer or third-party audit reviews.
Automotive Quality and Process Improvement Committee
Modification and Validation of a Finite Element Model of a Pedestrian Dummy09-14-01-00125/4/2026
Aims of the research This study aims to modify the lower body (the pelvis, thigh, and leg) of the mid-sized male pedestrian dummy FE model by considering the latest version of the physical dummy and to evaluate both the accuracy by comparing test results of the past studies and the biofidelity specified in SAE J2782 in both component and full-scale validations. Methods 1 Component validation The validation of the modified pelvis model was performed in dynamic lateral compression simulations. The sacrum and the pubis force-deflection responses of the iliac or the acetabulum impact were measured. The modified thigh and leg models were evaluated in a dynamic 3-point lateral bending simulation, measuring the force-deflection responses. The results from the simulations were compared with test results and the biofidelity requirements. 2 Full-scale validation The whole-body model was updated by incorporating these modified component models. The model of the generic buck developed for the
Asanuma, Hiroyuki, Gunji, Yasuaki, Mori, Fumie, Nagashima, Akiko
Assessing Injury Prediction with Human Body Models: Application to Rib Fracture Risk Prediction Using SAFER HBM09-14-01-00235/4/2026
As a consequence of the introduction of mathematical human body models (HBMs) in consumer information programs, there is an increased need for reliable methods that can demonstrate and build trust in the capability of HBMs to predict human response and injury risk in crashes. Therefore, a framework for validation of strain-based injury prediction is proposed. The framework comprises stepwise validation with the final step to validate the utility of risk predictions by means of the area under the curve (AUC) combined with Brier scores. SAFER HBM V11.1.0 previously validated at component and body part levels was selected for the demonstration of the final step of the framework to validate the capability to predict fracture risk in frontal, oblique, and lateral loading. For frontal loading, five postmortem human surrogate (PMHS) test series with 43 PMHS (age range: 19–88 years) were reconstructed. The predicted rib fracture risk for 2+ and 3+ fractured ribs was compared to the number of
Pipkorn, Bengt, Niranjan Poojary, Yash, Osth, Jonas, Larsson, Karl-Johan, Iraeus, Johan
Regional-Specific Patterns of Abdominal Injury in Belted Male and Female Frontal Crash Occupants: Insights from Redefined Anatomical Mapping09-14-01-00025/4/2026
Research Question/Methods The study examined abdominal injuries of 87 belted occupants in CIREN frontal crashes for sex-based differences in abdominal injury patterns. It introduced a more anatomically detailed method for identifying injury locations in an abdominal-pelvic region that includes skeletal structures. The study introduces and applies a novel Abdominal New Injury Severity Score (AbNISS) to address limitations of traditional AIS coding in capturing sex-based differences in injury patterns. The operative reports/EDR/imaging data in CIREN cases enabled identification of sex-specific crash outcomes. The dominant analytical motif is Betrand Russel’s knowledge by acquaintance and definite descriptions. Results Females had a higher rate of moderate to severe abdominal injuries than males: Only females sustained AIS 5 injuries, lumbar Chance fractures, posterior pelvic arch injuries, and more AIS 2, 3, and 4 injuries, with more injuries in superior-mid, left-superior, and medial
Halloway, Dale, Curry, William, Somasundaram, Karthik, Pintar, Frank
Characterization of Pedestrian Automatic Emergency Braking Acceleration in Modern Light Vehicles: Potential Implications for Occupant Safety09-14-01-00075/4/2026
The objective of this study was to characterize and compare pedestrian automatic emergency braking (PAEB) pulses in modern light vehicles to understand the loading environment that vehicle occupants are being exposed to during PAEB maneuvers. PAEB tests (n = 8008) conducted using 2018–2023 vehicle model years were analyzed. Pulse, vehicle, and impact characteristics (e.g., jerk, peak acceleration, pedestrian scenario, etc.) were derived from each PAEB test. Two k-means clustering analyses were used to group PAEB pulses with and without target collisions based on their similarity between characteristics. One-way ANOVA and Kruskal–Wallis tests were performed on the PAEB pulse characteristics to examine differences between clusters (p < 0.05). Two non-collision clusters (NC1 and NC2) were identified for PAEB pulses without collisions: NC1 had a statistically significant lower jerk (0.8 ± 0.4 g/s) and peak acceleration (1.0 ± 0.1 g) compared to NC2 (1.6 ± 0.8 g/s and 0.9 ± 0.1 g
Witmer, Maitland, Kidd, David, Graci, Valentina
Increasing the Competency and Confidence of Older Drivers in the Use of Advanced Vehicle Technologies: The MOVETech Randomized Controlled Trial09-14-01-00135/4/2026
Programs that teach older drivers how to confidently and competently use advanced vehicle technologies (AVTs) are limited. The MOVETech study evaluated a training program specifically designed to teach older drivers how to use these technologies. Participants (n = 119) were randomized to the intervention (training program) or control group (brochure). The intervention involved an in-person classroom education session on the use and benefits of AVTs, and an on-road driving session where participants drove along a pre-defined route in a dual-controlled vehicle with instruction on AVT use by a driving instructor. All participants completed in-person and telephone assessments at baseline and 3 months. Driving performance and on-road AVT competence assessments were the primary outcomes. Self-reported driving confidence, competence, and confidence in use of AVT, crashes, citations, and count of vehicle damage were the secondary outcomes. Program fidelity was also evaluated using a checklist
Nguyen, Helen, Ren, Kerrie, Coxon, Kristy, Neville, Nick, O’Donnell, Joan, Cheal, Beth, Brown, Julie, Keay, Lisa
Directional Stiffness Decoupling in Meta-Wheels via Three-Dimensional Discrete Curved Spokes15-19-01-00054/22/2026
Meta-wheels—non-pneumatic wheels whose performance is governed by structural geometry rather than internal pressure—offer new opportunities for directional stiffness control. Yet achieving independent tuning of longitudinal, lateral, and vertical stiffness within a single wheel architecture has remained challenging due to the inherent coupling in conventional radial and planar curved spokes. In this study, we introduce a three-dimensional (3D) discrete curved-spoke design that provides explicit geometric control through two independent parameters: the in-plane curvature angle (α) and the out-of-plane inclination angle (β). Using spoke-level and full-wheel finite-element (FE) simulations, supported by a simplified cantilever-beam analytical model, we show that these two geometric parameters govern stiffness in fundamentally different ways. The curvature angle α serves primarily as a geometric softener, reducing stiffness in all directions while maintaining a high top-loading ratio (TLR
Han, Heeseung, Liu, Zhipeng, Ju, Jaehyung
Real Turbulent Flow in Vehicle Aerodynamics: Overview of On-Road Measurements and Turbulence Generation in Wind Tunnels2026-01-50294/22/2026
Flow conditions on the road are quite different from the conditions used to develop vehicle aerodynamics. However, a significant amount of statistical data now exists that describes realistic road conditions. Some of these on-road flow characteristics can be replicated in wind tunnels. This paper reviews technical facilities designed to simulate on-road flow characteristics, such as turbulence intensity, turbulent length scales, and flow angle distribution. Reconstruction of a flow field that matches real road conditions is made possible by using active or passive turbulence generators within the wind tunnel. This review provides a comprehensive overview of these facilities, offering readers key insights into the challenges involved in replicating real-world flow conditions in wind tunnels.
Vondruš, Jan, Vančura, Jan
Engine Cooling Fan Structural AnalysisJ1390_202604 (Current)4/13/2026
Three levels of fan structural analysis are included in this practice: a. Initial structural integrity. b. In-vehicle testing. c. Durability (laboratory) test methods. The initial structural integrity section describes analytical and test methods used to predict potential resonance and, therefore, possible fatigue accumulation. The in-vehicle (or machine) section enumerates the general procedure used to conduct a fan strain gage test. Various considerations that may affect the outcome of strain gage data have been described for the user of this procedure to adapt/discard depending on the particular application. The durability test methods section describes the detailed test procedures for a laboratory environment that may be used depending on type of fan, equipment availability, and end objective. The second and third levels build upon information derived from the previous level. Engineering judgment is required as to the applicability of each level to a different vehicle environment
Cooling Systems Standards Committee
Failure Analysis and Improved Design of a Cycloidal Rotor Pump for Automotive Applications2026-01-01844/7/2026
Cycloidal rotor pumps are widely used in industries such as automotive and aerospace due to their advantages of compact structure, large displacement per unit volume, and low flow pulsation. With the development of new energy vehicles, rotor pumps are required to operate stably for extended periods under higher speeds, higher pressures, and harsher conditions, placing greater demands on their reliability. Addressing the specific problem of fracture failure of the inner rotor in a certain cycloidal rotor pump during bench testing, this paper first conducted a theoretical analysis of the inner rotor's metallographic structure. The metallographic results indicated that the inner rotor fracture was unrelated to material quality but was instead caused by the improper positioning of the slot on the pump's inner rotor, making the slot root the weakest part of the entire rotor material. Furthermore, sharp corners existed on the inner slot surface, leading to significant stress concentration at
Li, Meng, Xie, JIa, Qin, Gongyu, Yang, Hanming, Wang, Liangmo
Strain-Based Fracture Assessment of Tailor Welded Blanks under Complex Loading Conditions2026-01-02314/7/2026
Tailor Welded Blanks are critical for automotive lightweighting yet prone to premature failure due to differential thickness and strength across the weld. This study utilized digital image correlation (DIC) to analyze the maximum in-plane principal Hencky strain (E₁max) and axial strain (εₐₓₐₗ) of TWBs under complex loading conditions, including biaxial and plane-strain states. Twelve distinct material stack-ups were tested to evaluate the impact of material difference on formability. Results indicated that differential properties significantly altered strain distribution, often forcing localization onto the thinner or softer sheet. While UHSS welds provided high load capacity with limited ductility, combinations using HSLA or IF substrates were susceptible to early localization and unstable fracture. Comparative heatmaps illustrate strain evolution across all samples, providing spatial insights beyond conventional force–displacement analysis. Metallurgical characterization confirmed a
Aminzadeh, Ahmad, Sheng, ZiQiang, Huang, Lu, McCarty, Eric, Biro, Elliot
The ML FMEA in Action: Lessons from Applications of Machine Learning Safety2026-01-00794/7/2026
Introducing machine learning (ML) into safety-critical systems presents a fundamental challenge, as traditional safety analysis techniques often struggle to capture the dynamic, data-driven, and non-deterministic behavior of learning-enabled components. To address this gap, the Machine Learning Failure Mode and Effects Analysis (ML FMEA) methodology was developed as an open-source framework tailored to ML-specific risks. This paper reports on the maturation of ML FMEA from an initial conceptual framework to a proven, practice-driven methodology. We make four primary contributions. First, we extend the ML FMEA pipeline with two new stages: a “Step Zero” for problem definition and system-level hazard analysis, and a “Step 5” for constructing ground truth or reward signals. Autonomous vehicle and humanoid robot applications are presented to illustrate the practical application and safety benefits of these additions. Second, we introduce tailored Severity, Occurrence, and Detection
Schmitt, Paul, Shinde, Chaitanya, Diemert, Simon, Pennar, Krzysztof, Seifert, Bodo, Poh, Justin, Lopez, Jerry, Mannan, Fahim, Mohammed, Majed, Chalana, Akshay, Wadhvana, Neil, Wagner, Michael
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