Browse Topic: Quality, Reliability, and Durability

Items (10,226)
In the process of replacing the rollers of the fabric cart of the tobacco storage cabinet, in order to solve the problems of low replacement efficiency and high safety risk.This article proposes a specialized lifting tool for fabric cart rollers with a self-locking and adopts the screw lifting structure, which facilitates roller maintenance operations, and conducts SolidWorks Simulation calculations and dynamic simulation methods. Jinan Cigarette Factory fine cigarettes special line leaf silk temporary storage cabinet fabric car roller replacement, for example, the results show that: the average operating personnel reduced by 50%, the replacement time from 6.7h to 1.2h, efficiency increased by 458%, This innovation significantly reduces the labor intensity of maintenance personnel and ensures a safe and reliable replacement process.
Zhang, LeiXue, YifeiZhang, GeSun, YanzhaoWang, HongbinCheng, Linfeng
A test device for detecting the durability of the surface of elderly-friendly mattresses was designed and developed, which has functions such as force value monitoring, displacement monitoring, data recording, and hardness grade determination. Through the collaborative work of the mechanical system and the control system, high-precision reciprocating rolling tests and hardness grade determination on the mattress surface are realized. The verification test results show that the relative standard deviation (RSD) value of the mattress hardness grade test results is less than 10%, indicating that the detection data obtained by using this device is stable, meets the design requirements, and has operability.
Wang, JinFeng, PanpanShen, GuofengZhang, Lei
Recent advances in precision motion technology have heightened the requirement for precise stiffness analysis in flexible mechanisms. This paper begins with a theoretical analysis, constructing a mathematical expression for the stiffness of flexible mechanisms, providing a systematic framework for analysis. Subsequently, the study employed finite element analysis on both single and double parallelogram flexible mechanisms to validate the proposed theoretical stiffness formulas. This process not only confirmed the effectiveness of the proposed expressions but also highlighted the influence of different structures on stiffness characteristics. The finite element analysis results validate the proposed theoretical model as an effective and reliable tool for predicting the stiffness of flexible mechanisms. By establishing a reliable predictive model, this research paves the way for the informed design and systematic optimization of next-generation flexible mechanisms in precision motion engineering.
Cai, Dongchen
To address the challenge of accurately assessing the reliability of complex equipment, a reliability evaluation system for a five-axis machining center was developed based on extension theory. By collecting and analyzing the failure modes and data of various subsystems, the strengths of the Fuzzy Analytic Hierarchy Process (FAHP) and the Entropy Weight Method (EWM) were combined to determine the weight of reliability evaluation indicators for both the machining center and its subsystems. A comprehensive assessment of the five-axis machining center's overall reliability was conducted. According to the principle of maximum membership, the reliability grades for the spindle system and the feed system were both rated as “excellent.”
Fei, ShouxiangWang, DechaoPiao, ChengdaoZheng, Shengkui
This paper studies the applicability of the CDTire tire model in vehicle comfort and durability simulations by comparing it with the FTire tire model. Based on a physical 250/50 R19 tire, the corresponding CDTire and FTire models are developed and integrated into a multibody dynamics model of an SUV. After simulations of two handling comfort conditions and one durability condition using the CDTire and FTire models, it is found that, when FTire is used as the base case, CDTire produces a smaller relative error in vehicle comfort simulation, with a maximum of +5.6%. In the durability simulation, the relative error is larger, but the maximum value remains within ±10% at + 9.7%. Therefore, it can be concluded that CDTire is one tire model with acceptable simulation accuracy for vehicle comfort and durability.
Gao, FenglingWu, WenwenGeng, Hao
Reliability evaluation aims to quantify the reliability level of equipment and to verify its compliance with reliability requirements. Existing reliability evaluation methods primarily rely on operational phase data, which means reliability evaluation may lag behind actual needs. In practice, both users and design teams are more concerned with how to estimate CNC machine tools’ reliability before they are put into operation. Moreover, current reliability evaluation methods usually ignore the design team’s influence on CNC machine tool reliability. To overcome these limitations, this study proposes a novel reliability evaluation method that accounts for the influence of the design team on the reliability of CNC machine tools. By analyzing the impact of the design team’s technical capabilities and reliability capabilities on CNC machine tool reliability, a set of quantifiable evaluation indicators was established. Then, the weight coefficients of all indicators were determined using the expert scoring method. Finally, all data were integrated using the vector projection method, which enabled a quantitative reliability evaluation of CNC machine tools from different design teams within the same category. Additionally, the proposed method was applied to conduct practical case studies on multiple CNC external cylindrical grinding machine tools designed by different design teams, thereby validating the feasibility of the proposed method. The reliability evaluation results not only determine the reliability level of each CNC machine tool but also identify the weak points in the technical capabilities and reliability competencies of each design team. This study concludes by discussing the significance of this approach for enhancing the reliability capabilities of design teams and its practical implications for end users.
Sun, DongyangZheng, WeixuChu, HongyanXu, JingjingCheng, Qiang
This study presents a systematic investigation into the assembly stress and fatigue life of 60-series harmonic reducers. A sophisticated finite element simulation model is constructed to precisely simulate the real assembly process and calculate stress distribution in the flexspline under axial assembly errors. In addition, corresponding fatigue life tests are designed to explore the influence of different axial assembly errors on the number of rotation cycles and transmission efficiency of the harmonic reducer. By comparing the predictions of the fatigue life mathematical model with the test data, a reliable fatigue life prediction method is established, providing a solid theoretical basis for the whole-machine assembly process and reliability design of this series of harmonic reducers.
Du, YuefeiQiu, HaodongFan, YongLi, ZiyuanDong, YiZhang, ChiLi, ChenzhengLi, Yuan
With the continuous development of large precision equipment, the reliability requirement for long-distance transportation is also constantly increasing. Large packaging box with sealing and vibration reduction performance is crucial during transportation. This article introduces the sealing measures for large-sized packaging box, as well as the sealing structure design methods for key parts, vibration reduction measures and the selection and design of vibration dampers. The designed packaging box has been used for long-distance transportation of various types of equipment and the reliability of sealing and vibration reduction performance has been verified in practical applications, providing reference for the design of similar packaging boxes.
Zhang, RuoyuJiang, Shouli
Fleet heterogeneity, from manufacturing variations and diverse operating conditions, complicates reliability analysis by obscuring true failure patterns in aero-engines. This is a critical challenge in an industry as inaccurate Mean Time Between Failures (MTBF) estimates threaten safety and inflate operational costs, by forcing a choice between inefficiently conservative maintenance or the risk of in-service failures. Conventional analysis often fails by pooling all fleet data. To address this, our paper presents an analytical framework that improves predictive accuracy by filtering, rather than aggregating statistical noise. The methodology uses a Randomized Block Design (RBD) and ANOVA hypothesis test to screen a diverse dataset and isolate statistically homogeneous subgroups. This filtration identifies a core fleet with a consistent failure signature, providing a purified dataset for modeling. This refined data is then modeled using both Weibull and the Exponentiated Inverse Weibull distributions to ensure the results are robust and not model-dependent. Applying this framework to a 25-engine dataset that experienced 66 failures, we isolated a stable failure pattern, yielding a primary MTBF of 171.16 hours and a cross-validated MTBF of 176.35 hours. The close 3% convergence between these models validates our approach. By providing a dependable MTBF, this work establishes a stronger foundation for data-driven Reliability Centered Maintenance (RCM). It empowers maintenance planners to move toward evidence-based intervals, safely extending engine time-on-wing, optimizing spare parts inventory, and significantly reducing direct operational costs for airlines.
Jubaid, Mayin UddinBebe, GibsonBigyen, Musa PethuelAnik, S M Kullul MehedeeYasmin, AshrafiSahran, Mohamed Sideek Mohamed
During the cutting process of low-stiffness structural components, the coupling effect between dynamic deformation and cutting forces presents a significant challenge in accurately predicting machining-induced deformations, thereby complicating quality control in the manufacturing of such parts. To address this issue, a cutting force-structural coupling simulation method that combines experiment and finite element is proposed, which takes into account the low-stiffness characteristics of structural components. Focusing on thin-plate parts as the research object, an orthogonal experimental scheme is designed considering workpiece thickness that serves as an indicator of rigidity. A milling force prediction model correlated with workpiece thickness is established. Based on the predicted cutting forces, a multi-analysis-step simulation method is introduced to analyze the machining deformation of structural parts. Additionally, a theoretical analytical model for the machining deformation of thin-plate workpieces is developed. A comparison between the theoretical and simulation results shows a relative error of less than 1.03%, validating the accuracy of the proposed simulation method. Finally, the exponential regression model for the machining deformation is constructed using training data obtained from the simulations. The prediction error of the regression model is less than 15%. The findings of this study are also applicable to predicting machining deformations in other large and low-stiffness structural components.
Zhao, YongshengGao, PengfeiXu, JingjingLiu, Zhifeng
Fatigue design is a key common quality technology for improving the quality control capability of China’s automotive products. The fatigue of materials is a multi-scale damage evolution process. Characterizing and processing the large number of three-dimensional defects inside the material, which have different shapes and distributions, and predicting the material’s lifespan based on the cross-scale damage evolution mechanism, is one of the key technologies for fatigue optimization design. This paper discusses the research methods for the fatigue life of aluminum alloy materials. Firstly, based on the staged fatigue damage experiments, the three-dimensional defect features are obtained through CT scanning and reconstruction, and a defect characterization and processing method based on k-d tree and multi-scale feature pyramid is established to accurately represent the topological and geometric relationships of non-uniformly distributed three-dimensional defects. Secondly, a mathematical model for the evolution of micro-damage and macro-cracks is constructed, and the cross-scale transformation of defects is achieved through hierarchical and recursive methods, revealing the cross-scale evolution mechanism of fatigue damage in aluminum alloy materials. Finally, a remaining life prediction model based on defect information and feature weights is established through the support vector regression algorithm (SVR). This research method can provide technical support for the fatigue life optimization design application of lightweight materials such as aluminum alloys.
Zhang, LiangxiaNiu, ZhijunCheng, FangfangChen, HaoYang, Yali
In port construction, high-pile wharves—a primary structural form—are constantly exposed to marine environmental erosion, making corrosion a particularly prominent issue. Traditional anode installation typically relies on underwater diving operations, which suffer from low efficiency, high risks, and significant costs. To address these challenges, a novel installation technique requiring no divers has been developed. Through specialized equipment design and optimized construction processes, this technology enables remote, efficient, and safe anode installation. Research focuses on the design of non-diver anode support installation equipment, safety validation, and construction methodologies. Through theoretical analysis, numerical simulation, and field construction trials, this technology significantly enhances construction efficiency while reducing operational risks and costs. It provides a reliable solution for corrosion protection in high-pile wharves and holds significant importance for advancing port construction technology.
Lan, JinpingZhang, Shoulong
Traditional methods for assessing bridge resilience often focus on single hazards or static conditions. Yet bridges today face more complex multi-hazard threats. To address this, this research develops a dynamic model to evaluate bridge resilience under multi-hazard conditions, which is intended to provide scientific support for decision-making to improve resilience. The study first establishes an index system that measures a bridge’s ability to absorb impacts, adapt during an event, and recover afterward. We also propose a method to calculate the coupling degree, which quantifies the amplification effect of multiple hazards, such as an earthquake followed by a flood, on each other’s impacts. Next, we clarify the interrelationships among key resilience factors. Using this understanding, we construct a system dynamics model that simulates the variation of bridge resilience over a full disaster cycle. Finally, a numerical simulation is carried out for a concrete continuous girder bridge in China’s coastal areas as a case study. The results confirm the model is valid and clearly show the differences in bridge resilience between single-hazard and multi-hazard events. More importantly, they prove that combined hazards make the bridge system much more vulnerable. The model also identifies the best strategies for intervention: a strategy that coordinates actions across all disaster phases performs best, as it most effectively reduces the impact of compound hazards and keeps the resilience curve smoother. In short, this study presents a new method for assessing bridge resilience and provides engineers and managers with a practical tool to identify structural weaknesses and optimize resource allocation for resilience improvement.
Lin, JiachenChai, Liang
Aligned with the “3060 dual carbon” goal, the rapid growth of new energy installation capacity in China’s western high-altitude regions has caused an urgent demand for UHV converter station construction. This paper suggests a prefabricated structural system by using embedded ear-shaped tongue-and-groove UHPC wall-column connections to meet the challenges of traditional cast-in-place concrete firewalls, such as prolonged construction periods and difficulty in quality control in harsh environments. The seismic performance of the connection was investigated through pseudo-static tests and finite element analysis. The results show that failure mainly occurs on the wall–column interface, with cracks mainly appearing at the wall panel corners. The scaled model demonstrated full hysteresis loops, indicating stable energy dissipation. The ear-shaped tongue-and-groove connection showed superior initial stiffness and ultimate load-bearing capacity (404.3 kN) compared with the straight-type connection (177.5 kN). An increase in the semicircular diameter improved load capacity, while the axial compression ratio had little effect. This study proposes a theoretical reference for the design and application of prefabricated valve hall structures in high-altitude regions.
Wang, FengyunYan, YongZeng, ChengZhou, TingRen, Zhaoyang
Transporting large steel materials for mountain electric towers is challenging due to steep gradients, narrow roadways, and uneven terrain. To address these issues, this study designs an adaptive attitude adjustment mountain transport vehicle. This mountain transport vehicle has a compact structure, measuring 1.4 meters in length and 1.1 meters in width, which enhances its suitability for confined mountainous environments. This vehicle adopts a design scheme that combines hydraulic lateral adjustment, load-bearing platform follow-up adjustment and frame adaptive adjustment mechanisms. The transportation of tower materials, measuring 12 meters in length and 1.2 tons in weight, is accomplished by employing two vehicles working in coordination. The three-dimensional model of the entire vehicle is established by using SolidWorks software. The lateral stability of the mountain vehicle and the limit working conditions of its adjustment mechanism are analyzed through theoretical calculation. The dynamic simulation of the virtual prototype is carried out using Adams software, including the processes of lateral leveling, follow-up adjustment and frame adjustment. The results show that the leveling mechanism can achieve an adjustment range of more than ±25°. The results confirm the vehicle’s excellent stability and adaptability to mountainous conditions. This study provides a more effective and more reliable solution for the construction of mountain electric towers than traditional manual or animal-powered transportation methods.
Zhang, RuiKong, FanfangHe, YulingLv, JiahuiChen, ChanglongZhan, LulinLiang, Ke
Tubing Ultimate burst strength Full scale test
Cheng, WenjiaYang, HongbinGe, YuanZhong, ChongdiMeng, LingkunJi, BingyinShi, Jiaoqi
Ball screws, as classic high-precision transmission structures, are widely used in various linear motion mechanisms. To meet the needs of space applications, it is necessary to address issues such as microgravity and long lifespan to enhance the in-orbit lifespan and reliability of ball screws. Traditional oil or grease lubrication methods are often unsuitable for space environments due to microgravity and vacuum evaporation problems. This paper conducts relevant research on lubrication design, friction pair design, and friction and wear verification to solve the lubrication and lifespan issues of long-lifespan ball screws for space applications.
Xie, WenZhao, JianGong, KangHu, XiaonanGuo, MengleiJiao, Hanyu
This research overcomes the serious problem of unregulated fastener substitution in aviation manufacturing, which is due to supply chain disruption, design modification, improved production, and permanent installation of substitute fasteners other than temporary installation substitutes. It can introduce potential risks, including the differences between designed and as-built configurations, and problems with the structural strength of parts. Analysis of a 20XX aircraft model that has been documented with 9 types of fasteners reveals that shortages of 4CE5 and 1CD6 remain constant manufacturing nonconformities and a major element causing long term quality erosion. We have developed an early warning system centered on data with the introduction of the Tolerable Substitution Ratio (TSR) and the non-substitution ratio (NSR). Empirical results show that after implementation, the substituted materials can save as much as 25%, which is approximately $534,000 on domestic sourcing costs and permanently revised drawing costs. We should consider both users’ specifications and the production facility’s actual capabilities when designing the degree of substitution tolerances; substitution deviating from the original specification would not be tolerated. For an extended cycle longer than one year, phase adaptive tolerance adjustments are critical for achieving the acceptable quality limit (AQL). Real-time alignment of the key trigger point in the process stream with supply chain analytics takes away the historical trade-off between operational efficiency and the quality of the final deliverable. The result of this process is that there were more than 1,600 fewer ad-hoc deployments but higher levels of system stability, even as the processes had become more unstable. The payoff in terms of verified protocols for mitigating risk was much greater.
Feng, Yu
Craters are the primary landmarks used for visual navigation in missions exploring small celestial bodies. However, obtaining high-quality, annotated crater data is often challenging due to limited imaging conditions and strict mission constraints. Conventional semantic segmentation models struggle with limited data and are challenging to train effectively. To overcome this limitation, this study introduces a few-shot segmentation approach for crater detection on small celestial bodies. Our method includes a prototype representation module that constructs class-level prototypes to quickly associate crater regions with their semantic features. This paper also designs an iterative learning module that gradually improves the segmentation output, helping the model better capture detailed edges and structures. Tests on a simulated few-shot dataset demonstrate that our method provides reliable and accurate crater segmentation, achieving a mean intersection-over-union (mIoU) of 88.7, outperforming traditional fully supervised methods.
Li, ShuaiZhu, Shengying
The climb gradient along the takeoff trajectory at each point during takeoff reflects the aircraft’s ability to clear obstacles and reach a safe altitude, ensuring the safety of civil flights. Airworthiness regulations specify certain requirements for the single-engine-out climb gradient. Given that the data used in conventional calculation methods are significantly influenced by the flight status during the process, this paper explores two new climb performance calculation methods based on the existing ones. A set of data was calculated, and the resulting errors were all no more than 10%, indicating that both new calculation methods are effective and reliable. Therefore, they provide a certain reference value for the climb gradient calculation of transport category aircraft.
Jiang, TianjunLiu, Tao
Requirements of Interface for Aircraft/Store Electrical Interconnection System (GJB 1188A-99) is the current standard followed by all types of carrier aircraft and stores. This paper designed a 1553B bus remote terminal mode code configuration method that met the requirements of GJB1188A standard, completing the interrupt initialization and data initialization of compulsory mode codes. These comprehensive test results confirm that the proposed mode code configuration method is both reliable and effective, and provides strong portability, which can be used as a reference for the GJB1188A interface software design of other components
Han, BinZhang, KunLiu, XuhanYe, JinhanLi, Zhengmao
Multi-UAV cooperative localization can utilize information fusion between nodes to improve localization accuracy and performance on the target. Distributed state fusion estimation methods have been heavily studied in recent years, but the final estimates in the research results do not converge towards the global optimum. This paper aims to make the state estimates of each individual in the UAV formation for the target converge and converge to reliable values. In this paper, we study a multi-UAV cooperative tracking method based on adaptive weighted fusion, which first evaluates the importance of each node in the UAV formation and the reliability of the local filtering estimation results, and then assigns the weights according to the reliability of the UAV’s local state estimation of the target in the whole at the current moment. Finally, this paper verifies through simulation experiments that the method can not only accomplish the state tracking of the target, but also that the state estimates of each node in the network converge to more accurate state estimates.
Xia, ShengjiWang, ChangqingLiu, FaleiJia, ZhaoxuanZhao, Quanpu
This document contains information and guidance on assessment of the risk posed by observed tin whiskers for aerospace, defense, and high-performance (ADHP) products or other products that demand high reliability.
G-24 Pb-free Risk Management Committee for ADHP
The magnetic field modeling methodology for ships based on magnetic dipole arrays demonstrates heightened sensitivity to input data. When addressing overdetermined systems characterized by numerous variables and constrained measurement points, the coefficient matrix frequently develops pathological ill-conditioning, leading to solution divergence and compromised result accuracy. This research reformulates the ship magnetic field inversion challenge as a non-convex quadratic programming problem, employing the Successive Convex Approximation (SCA) algorithm as the computational solver. Rigorous comparative validation was performed against conventional stepwise regression algorithms and experimental datasets acquired from scaled ship model measurements. Results substantiate that while the modeling precision of the SCA algorithm remains comparable to that achieved by stepwise regression methods, SCA exhibits demonstrably superior solution stability. This enhanced robustness positions SCA as a more reliable computational framework for critical naval applications, particularly in high-fidelity ship magnetic signature modeling and rapid detection/localization of magnetic targets in marine environments.
Chen, HaoPan, Xun
The reliability of aviation maintenance personnel directly impacts flight safety, yet systematic methodologies for the quantitative prediction of human error probability (HEP) in this domain remain lacking. To address this gap, a novel human factors reliability analysis method for aviation maintenance is proposed, extending the SPAR-H model through Evidential Reasoning (ER). This method is implemented as follows: Maintenance tasks are decomposed into subtasks. Subsequently, the eight types of Performance Shaping Factors (PSFs) for each subtask are evaluated by domain experts according to defined PSF levels. Expert judgments are then aggregated using Evidential Reasoning theory, enabling the calculation of aggregated PSF levels. These aggregated levels are interpolated to determine the corresponding impact multipliers. Finally, the HEP for aviation maintenance operations is calculated by integrating the SPAR-H basic error probability model with task series/parallel logic rules. The proposed methodology is validated using an inspection operation case study. This study establishes a methodological framework for human factors reliability analysis in aviation maintenance, providing a theoretical foundation for developing scientifically grounded prevention and control measures to enhance aviation safety levels.
Meng, MengMa, NingGuan, ZhongqingHan, ZuyangNan, WenxueCai, Hongbin
Vehicle vibrations during precision instrument transport can cause damage and failure. Existing vibration isolators often lack reliability, mass production feasibility, and easy maintenance. In this paper, we design and analyze a quasi-zero-stiffness vehicle-mounted isolator with an inerter, decreasing dynamic stiffness while raising the effective mass. Theoretical, simulation, and experimental results show improved isolation performance, lower isolation frequency, and a broader isolation bandwidth.
Li, KaiLv, SiboSun, NingDai, Shijie
The gearbox is a key component of the mechanical transmission system, and its fault diagnosis is essential to the reliability of the equipment. However, obtaining fault samples under actual working conditions for gearbox fault diagnosis is challenging. In this paper, the rigid-flexible coupling dynamic simulation model of the gearbox is established, and the co-simulation of gear normal, crack, and breakage is carried out in the ADAMS and MATLAB environments. The comparison between the simulated and measured signals shows that the simulation method can accurately reflect the key characteristics, such as rotation frequency and meshing frequency, and verify its reliability and accuracy. The research results can provide effective data support for gearbox fault diagnosis and improve the operational safety of mechanical systems.
Li, DongxiaoZhang, QianqiZhang, ZhongzhengLi, Yongbo
Aiming at the problem of insufficient modeling of spatio-temporal heterogeneity in road traffic accident prediction, a dual task machine learning framework integrating geographical environment, location attributes and time periodicity is proposed. The dataset used in this study was derived from traffic accident records of Nanchang during 2019–2023. Firstly, geographical identifiers are generated by rounding and aggregating latitude and longitude coordinates. At the same time, the location type is processed by a one-hot encoding, so as to carry out spatial clustering analysis of accident hotspots. Compared with the North-South pattern, the contribution of geographical features shows a strong East-West trend. The kernel density heatmap identified Zone A and zone B as dual core high-risk areas. Secondly, the sinusoidal/cosine function is used to encode the time feature circularly, which effectively captures the daily change of the accident. The quantitative analysis of random forest regression model showed that time characteristics accounted for 89.2% of the variance of accident frequency interpretation, significantly exceeding the contribution of geographical factors (10.2%) and location attributes (0.6%). After hyperparameter optimization, the accuracy of XGBoost classifier in predicting serious accidents is 75.97%, and the AUC value is 0.8412, which has strong robustness, and provides reliable support for dynamic risk assessment of traffic management system.
Luo, JiangZhang, YuxinLi, XinWu, Ronghai
In vehicle production, commissioning and testing processes of electric and electronic components are essential for value creation and quality assurance. The emergence of software-defined vehicles, however, leads to an increased scope and complexity of these processes as software functions depend on electric and electronic components for perception, execution, and processing tasks. In this context, this paper tackles a common challenge: Software that is deployed in vehicle production to implement commissioning and testing processes is developed upon specifications that define prerequisites, procedures, and target results in natural language. Therefore, extensive human interpretation and manual translation into executable code are needed being susceptible to errors as well as time-consuming. The large number of vehicle configurations and rapid changes in vehicle software further complicate the development of commissioning and testing software, particularly as verbose textual dependency descriptions risk impairing comprehensibility. Machine-processable specifications facilitating automated validation and code generation or direct execution could consequently ensure consistency, reduce manual effort, and accelerate the development process. For this purpose, we examine the processability of commissioning and testing specifications in natural language by proposing a pipeline designed to systematically transform these specifications into a machine-processable format. In particular, we introduce a unified schema that serves as an input format for the large language models tasked with the transformation. Subsequently, several large language models are evaluated in practical trials, based on their ability to translate commissioning and testing specifications into a machine-processable notation. In summary, this study aims to enable more efficient and data-driven software development based on textual requirements. This work offers valuable insights into the suitability and applicability of large language models within the planning of automotive commissioning and testing processes, targeting enhanced automation and efficiency.
Köhler, KatjaEl Asad, AimanHahn, MichaelReuss, Hans-Christian
Stochastic preignition (SPI) or low-speed preignition (LSPI) is an abnormal combustion phenomenon observed in downsized turbocharged direct-injection spark-ignition engines at highly boosted conditions. SPI results from the ignition of the air-fuel mixture from a fuel or oil droplet or a detached deposit before the spark discharge, and its occurrence can lead to extremely high peak pressures and severe knock, which can cause physical damage to the engine. This phenomenon limits the downsizing and boosting potential of direct-injection spark-ignition engines, thereby constraining the efficiency benefits that can be achieved. The propensity for SPI to occur is impacted by engine operating conditions as well as the properties of the fuel, fuel additives, lubricant, and lubricant additives. To mitigate its occurrence, it is important to understand the factors that impact the frequency of SPI events. As this abnormal combustion phenomenon is relatively recent, there was a lack of a standard procedure to detect the impact of a parameter on SPI frequency. This study details the development and validation of an engine dynamometer test procedure—the TOP TIER™ Standardized Dynamometer Test Method to Evaluate Additized Detergent Gasoline for SPI—approved by the Center for Quality Assurance (CQA), to evaluate gasoline additives for their impact on SPI. In this project, the newly validated SPI test protocol was used to compare the relative SPI tendencies of four TOP TIER™ fuel additives at maximum retail concentration against unadditized SPI test fuel, which served as the baseline. All four fuel additives were tested three times in randomized order. The results revealed that none of the TOP TIER™ additives tested had a statistically significant impact on the SPI rate.
Gopujkar, SiddharthDavis, RichardWorm, JeremyTuma, NicShukla, PrajwalReilly, VeronicaChapman, ElanaCiaravino, JosephSeyfried, Philipp
Achieving best-in-class Noise, Vibration, and Harshness (NVH) in electric powertrains demands a paradigm shift in development methodology. This paper presents a practice-oriented overview of simulation methods in NVH development methodology for electric drive units. This includes target cascading and multi-objective optimisation, and by attacking NVH at the source using KPIs early in the design cycle, significant reductions in development time and reliance on traditional testbed loops are realised. Machine learning (Neural Network) algorithms are utilized to find the best-in-class design, using multi-objective optimisation as well as refining simulation accuracy by adding tolerance effects while target cascading ensures alignment of system-level performance objectives down to subsystem contributions. Combined, these strategies enable rapid and robust NVH optimisation, using simulation for next-generation electric powertrain development. Several applications and real-life examples demonstrate how simulation helped with NVH issue identification or improvement.
Mehrgou, MehdiGarcia de Madinabeitia, InigoGraf, BernhardGojo, Josef
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 phenomena and facilitates new root cause analysis (RCA) types and processes. To begin, we prove the numerical accuracy of the FBS algorithm deployed in the presented investigation by comparing its results with those obtained with superelements and without substructuring. We point out that because the used FBS process starts with a modal representation of the components rather than their frequency response functions (FRF) a different class of RCA type becomes available. Then we introduce new RCA types starting with an analysis named Modal Influence (MI) that reveals the effect of the modes of any component on a certain response. Its key characteristic is that MI analysis is not restricted to the response component opposite to the well-known modal participation factors. Finally, a second novel analysis type is introduced, an advanced 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.
Herbst, Markus
This work presents a modular engineering methodology (DiPhyBa - Digital Physical Balance) for the virtual validation of Noise, Vibration, and Harshness (NVH) performance in automotive development. The approach addresses the inefficiency of repeated physical testing across vehicle variants by introducing a structured two-phase process—Launcher and Reskin—centered on quantitative performance indicators with formal acceptance thresholds. In the Launcher phase, a digital replica of the base vehicle is built and iteratively correlated with physical test data. Validation is governed by objective indicators of confidence, conformity, and correlation, each evaluated against predefined thresholds. Once validated, the model becomes a certified reference, enabling its reuse across derivative configurations in the Reskin phase. Physical testing is only required if indicators fall below threshold, with a final gate test on pre-series vehicles ensuring industrial robustness. DiPhyBa formalizes the decision to replace physical testing with simulation, introducing automation, traceability, and repeatability into the validation workflow. The method is scalable across platforms and adaptable to other technical domains such as durability, thermal, and safety. The long-term industrial ambition is to progressively minimize redundant NVH testing on vehicle variants. Early applications demonstrate significant reductions in development time and cost, while enhancing confidence in simulation-based decisions. DiPhyBa bridges the gap between digital simulation and industrial validation, offering a new standard for virtual engineering in the automotive sector.
Celiberti, LuciaCamia, Andrea
To minimize 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 behavior of material combinations for a wide range of loading and climatic conditions. Conducted in a climate chamber with a standard stick-slip test 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 jolting movements with high excitation speeds. The result is a detailed map of stick-slip behavior as a function of excitation speed and climate. While requiring a similar level of effort as the traditional test, this approach delivers far greater insight. It enables a more reliable optimization of materials and facilitates targeted material selection for specific applications. In this manner, it can not only contribute to improve product quality but also to achieve quiet interiors and customer satisfaction.
Fritz, SusanneStrangfeld, Martin
The virtual development of Electric Drive Modules (EDMs) for Battery Electric Vehicles (BEVs) requires proven and predictive methodologies. One part of the development investigates the vibro-acoustic assessment for the low- and high-frequency ranges within the targeted operating range. The efficient use of such a methodology requires an understanding of the accuracy and validity of the achievable results, as well as the derivation of suitable improvement measures for goals that have not been achieved. The use 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, including the simulation approach, validation, and evaluation procedure. It discusses how RCA can be applied to different observed phenomena in EDM NVH behavior and detected deviations between the initial model and the measurements, the main influencing parameters, and the identified improvement potential for simulation models.
Klarin, BorislavPevec, DenisResch, ThomasEsposito, SaraD'Alessandro, VincenzoSpanu, Giorgio
In recent years, the automotive industry has actively explored the application of various AI-based models such as Convolutional Neural Networks (CNN), Long Short-Term Memory (LSTM) networks, Autoencoders, and Transformers to improve defect detection rates at the End-of-Line (EOL) stage. However, implementing these approaches in the Noise, Vibration, and Harshness (NVH) area face several practical challenges: ① extended evaluation times compared to other data types, which limit the quantity of training data and lead to overfitting; ② label imbalance caused by the relatively small amount of defect data; ③ reduced labeling accuracy due to human error; ④ decreased robustness under domain shifts such as changes in jig fixtures, test environments, and signal-to-noise ratio (SNR); ⑤ diminished model reliability when new defect arise during development; and ⑥ constraints imposed by compatibility requirements with existing test equipment. This study proposes a Convolutional Autoencoder (CAE) based framework trained on NVH datasets collected from normal and defective Column-type Electric Power Steering (C-EPS) systems. Latent variables at the bottleneck layer are used for dimension reduction, enabling visualization and unsupervised classification using a clustering algorithm. A classification model derived from the encoder is fine-tuned with clustered data, and Gradient-weighted Class Activation Mapping (Grad-CAM), an eXplainable AI (XAI) technique, is applied to extract Feature Frequency Maps (FFM) highlighting defect-related noise and vibration characteristics. The proposed approach does not rely on the deep learning model to directly classify defect. Instead, it utilizes extracted FFM as weights(mask) to detect defect. This method enables quantitative data representation and ensures high applicability with existing EOL equipment. Post-processing within the FFM enables root cause analysis, reducing issue resolution time and supporting integration with conventional signal analysis techniques.
Park, Jun-SeoJo, Hyeon-ChoelCho, In-JeSeo, Jae-YongYoo, Seong-Sik
Agricultural vehicles operating in rough environments experience increased fatigue damage accumulation, which may decrease machine safety and reliability. Autonomous agricultural machines offer an opportunity to incorporate fatigue damage considerations into path planning. This work investigates whether machine learning can predict fatigue damage to a tractor chassis using light detection and ranging (LiDAR)-based terrain features, vehicle speed, and rotational vehicle state data (e.g., triaxial angle, angular velocity, and angular acceleration). Fatigue damage was estimated using the Rupp filter and the Durability Transfer Concept. Following poor predictive performance of the machine learning models, an exploratory analysis of damage histograms, dominant frequency, and acceleration magnitude was performed. Results indicated that most estimated fatigue damage occurred in the 0–2 Hz band, which coincides with the frequency range of terrain-induced acceleration. On-road driving led to the greatest fatigue damage, potentially due to the harder driving surface and increased vehicle speed. Differences between root mean square (RMS) acceleration magnitude and fatigue damage indicate that isolated high-magnitude events may have contributed to increased estimated fatigue damage. Several suggestions for future development were identified. Identification of the endurance limit of the tractor chassis will permit the removal of nondamaging events, improving label accuracy. Furthermore, the presence of a front-loader implement may have impacted chassis acceleration. Thus, a comprehensive dataset with multiple implement configurations is needed to determine the influence of implement configuration on dynamics and resultant damage.
Govers, Megan EmilyHamilton-Wright, AndrewHassan, MarwanOliver, Michele L.
This digital standard is a requirements extract of AS9145 Requirements for Advanced Product Quality Planning and Production Part Approval Process. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
This digital standard is a requirements extract of AS13100A Quality Management System Requirements for Aero Engine Design and Production Organizations. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
This digital standard is a digital model of AS9100D Quality Management Systems - Requirements for Aviation, Space, and Defense Organization. This file contains an MBSE model in a mdzip file for use in modeling applications.
This digital standard is a requirements extract of AS13001A Delegated Product Release Verification Training Requirements. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
This digital standard is a requirements extract of AS4159 Specification For An Automated Interchange Of Standards Data. This file contains a general requirements extraction as well as files that are optimized for use with Doors Classic, Siemens Polarian, and PTC.
Aircraft lighting systems play a vital role in ensuring operational safety, visibility, and regulatory compliance. Exterior lighting systems are essential for aircraft identification, navigation, collision avoidance, and ground operations under varying environmental conditions. These systems typically include navigation lights, anti-collision lights, landing and taxi lights. An aircraft lighting system comprises light sources, optical elements, electronic control units, power interfaces, wiring harnesses, and mechanical mounting structures. Among these components, optics are critical as they control light distribution, intensity, color accuracy, and efficiency while withstanding harsh aerospace environments such as vibration, thermal cycling, and aerodynamic loads. Aircraft exterior lights are subjected to severe thermo-mechanical stresses due to aerodynamic loading, vibration, and thermal cycling. The use of high-performance optical polymers such as Cyclo Olefin Polymers (COP) provides excellent light transmission and stability; however, their relatively lower mechanical toughness makes them susceptible to stress-induced cracking during assembly. In the baseline configuration, the Circuit Board Assembly (CBA) was fastened directly onto the optic using self-tapping screws. During assembly, frequent crack initiation was observed in the optic around the fastener locations, leading to concerns regarding reliability and maintainability. To address this issue, a redesigned mounting approach was developed that eliminated direct fastener penetration into the optic. Instead, the CBA is retained using a precision clamping mechanism, thereby distributing assembly loads uniformly and avoiding localized stress concentrations. COP material was retained due to its superior optical characteristics and compliance with photometric requirements for aircraft lighting applications. The redesigned optic-CBA interface was validated through Highly Accelerated Life Test (HALT), incorporating combined vibration, temperature, and thermal shock profiles. Test results confirmed that the new clamping design prevented crack formation, improved mechanical robustness, and ensured long-term optical performance. This paper presents the problem definition, root cause analysis of fastener-induced cracking, the design rationale for adopting a clamp-based mechanism, and detailed HALT validation results. The study highlights the importance of integrating material properties, fastening strategies, and environmental testing in the design of aerospace lighting systems. The proposed design methodology provides a pathway to enhance reliability and lifecycle performance of critical optical components in aircraft applications.
Vialta, FredericoS, NikhilKatageri, PraveenSP, PradeepSingh, Abhimanyu Kumar
Using vibration data to estimate buckling loads is proven effective for a wide range of structures, including rods, plates, and shells. The Arbelo formulation of the vibration correlation technique improves prediction reliability for cylindrical and spherical shells. In this study, we introduce a simplified variant of the Arbelo approach that provides higher prediction accuracy while requiring significantly lower pre-load levels. We define a new parameter, the Stiffness Decay Index (SDI), to characterize stiffness degradation by normalizing the loaded natural frequency with respect to the unloaded state. This metric enables accurate buckling prediction without causing structural damage or permanent deformation. We evaluate SDI numerically and experimentally for multiple isotropic geometries and demonstrate its advantages over the Arbelo method, particularly for ellipsoidal domes subjected to external pressure. We conduct experiments on rods, plates, oblate shells, and beverage cans to measure frequency shifts under pre-loading. The results show that when load data above 50% of the critical value is available, the SDI approach predicts the buckling load with accuracy exceeding 90%. These findings confirm that SDI, by directly correlating vibration response with stiffness loss, provides superior buckling-load prediction and serves as a reliable, non-destructive alternative to the Arbelo vibration-correlation method.
Rangarajan, GopikrishnaV, VishwajithRaju, GangadharanDinavahi, Ramkrishna
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 Hardness change, were assessed through precision measurement techniques. Weight changes before and after immersion were also recorded to correlate material absorption characteristics with the success criteria. Success thresholds were established based on industry requirements for seal integrity and operational reliability. Preliminary results indicate that FKM exhibits minimal volume expansion and hardness change under specified conditions, aligning with the acceptance criteria. These findings support the suitability of FKM seals for long-term use in coolant systems, with implications for material selection and design in demanding applications. This research contributes to the development of durable sealing solutions, ensuring reliability and safety in systems utilizing ethylene glycol-based coolants. Keywords: FKM, Volume Expansion, ASTM D471
Yarolkar, MakrandPatil, SandipSingh, Tanul
This paper presents an automated framework for security compliance and quality assurance in DevSecOps CI/CD pipelines, specifically designed for safety-critical avionics software. The framework integrates regulatory compliance checks, security validation, and robust verification directly into the software development lifecycle, supporting continuous integration and delivery for aerospace applications. Automated processes such as code compilation, coding standards compliance, Cyclomatic Complexity Measurement, Sources Line of Code and CRC validation on target hardware are seamlessly orchestrated to maintain consistency and reliability. The system generates comprehensive compliance reports, highlights coding standard violations and security issues, and notifies relevant stakeholders to facilitate timely resolution and corrective actions. As new code is checked in, the framework automatically initiates all verification and compliance tasks, ensuring that every software update is thoroughly validated without manual intervention. Daily automated testing and coding standards checks are performed to maintain ongoing software quality and compliance. By automating key verification and compliance activities, the framework minimizes human error and supports efficient regulatory compliance throughout the development process. Integration of these capabilities within DevSecOps pipelines enables rapid, repeatable, and auditable software releases, significantly reducing manual effort and accelerating delivery of high-quality builds to customers. The framework enhances digital verification, validation, and certification readiness by providing comprehensive evidence required for regulatory audits, ultimately improving overall project assurance and reducing technical debt for aerospace software teams. These automation techniques collectively help organizations achieve verification processes of DO-178C standards more effectively, ensuring that safety-critical software meets stringent industry requirements while streamlining the certification process, reducing time-to-market, and enabling faster deployment of reliable solutions to end users and stakeholders.
Bhagwat, Shashank RaviChangappa, Naveen KumarNath, Sunny
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 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 evaluate multiple gate configurations. The system aggregates results and identifies optimal gate locations based on the initiation of failure under quasi-static loading conditions, thereby reducing reliance on trial-and-error and expert intuition. This approach not only streamlines the simulation process but also ensures that gate placement decisions are informed by comprehensive mechanical assessments across multiple load cases. The integration of Digimat’s ICME capabilities enhances simulation accuracy, leading to improved reliability and performance of SFRP components.
Kauthale, TanmayMadhavan, VinaySoni, Ganesh
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