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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
Aircraft assembly systems, as a critical phase in aerospace manufacturing, face significant challenges in maintaining production efficiency and ensuring product quality. This complex manufacturing system exhibits two distinct characteristics: (1) tightly coupled interactions among manufacturing elements involving process sequences, material flows, and equipment utilization; and (2) dynamic resource allocation and material distribution plans. The inherent variability in production element configurations often leads to operational instability and schedule deviations, which may result in abnormal production states. To address these challenges, this study proposes a data-driven predictive framework that integrates Long Short-Term Memory (LSTM) neural networks with multi-criteria evaluation. The developed LSTM-based model effectively forecasts two critical production indicators of cycle time and balance rate, achieving temporal prediction through historical operational data analysis. The proposed methodology facilitates timely anomaly detection and early warning, allowing proactive risk mitigation and ensuring sustained production system stability. This research contributes to advancing intelligent monitoring and control strategies for aircraft assembly operations within data-driven manufacturing environments.
Chen, BolinWu, JunjieSun, JinfengWang, Kai
Manual operations in traditional tea packaging lines often suffer from low productivity, safety risks, and inconsistent labeling quality. To overcome these limitations, this study develops a fully automated tea packaging system guided by an improved genetic algorithm. The system integrates five functional modules—bag feeding, bag opening, material filling, sealing, and labeling—into a seamless workflow. By applying the optimization capability of the improved genetic algorithm, the system achieves better coordination among modules, higher adaptability to different bag shapes and sizes, and improved operational efficiency. Experimental validation demonstrates that the proposed design not only simplifies the packaging procedure but also enhances precision, reliability, and production speed. The system provides a flexible and intelligent solution applicable to a wide range of tea packaging requirements.
Guo, HuiZhao, ZhikaiYuan, WeilongLin, LinYu, YunchangGao, Jiashun
In the marine environment, navigation safety and operational effectiveness depend heavily on the precision of liquid level/capacity measurement equipment and systems. In order to examine their measurement accuracy under complex operational situations, including ship navigation states and water tank sloshing, this study employed computational fluid dynamics (CFD) methodologies. The numerical technique performs a thorough examination of how various operating conditions impact measurement accuracy and integrates the volume of fluid (VOF) model and laminar flow model with appropriately defined boundary conditions and solver settings. The findings indicate that constant-speed navigation has minimal impact on accuracy, horizontal acceleration causes moderate deviations, and accelerated diving greatly reduces precision. The amplitude of water tank sloshing has a positive correlation with measurement error. When sloshing amplitudes are less than 1 m, the integration of the resulting acceleration efficiently lowers deviations while preserving excellent accuracy. In light of these results, we advise adding accelerometers to differential pressure transmitters to improve measurement precision. This investigation provides data-driven references and technical solutions for system design and operational standard formulation in marine measurement systems.
Shang, JinQin, ZimingWang, YingweiWu, ChaoZhao, FenggangChen, LiangXia, WeiYan, JinChen, MinChen, Guoao
To precisely simulate the nonlinear dynamic characteristics of a robotic arm grasping cylindrical objects from storage units, this study establishes a dynamic model of the robotic grasping process incorporating Coulomb and viscous friction models to characterize frictional properties. Furthermore, to effectively identify unknown parameters in the dynamic model, a parameter identification method based on the Superb Fairy-wren Optimization Algorithm (SFOA) is proposed. The root-mean-square error (RMSE) between the displacement responses from the dynamic model and the experimentally acquired displacement data serves as the optimization objective. Multiple sets of experimental data are utilized to identify the unknown parameters of the dynamic model. The results demonstrate that when the identified parameters are applied to the dynamic model, the goodness-of-fit between the model’s response displacement data and the experimental displacement data exceeds 0.999. This validates the effectiveness and accuracy of the proposed method for identifying unknown parameters in dynamic models.
Shen, ShaofengYang, LiuWang, ZihanHan, Qunyi
During root canal treatment, dentists must use endodontic access cavity preparation dental handpieces and root canal preparation handpieces separately for endodontic access cavity preparation and root canal preparation. To reduce the use of surgical tools, an integrated instrument for endodontic access cavity preparation and root canal preparation was designed. Driven by an air impeller and equipped with a quick tool disassembly unit, the instrument realizes forward or reverse rotation of the end tool via an STM32-controlled electromagnetic directional valve. The flow characteristics of the air impeller system were analyzed using ANSYS CFX, and the results showed that the impeller output torque met the design requirements. To minimize torque fluctuations during rotation, a double-layer offset impeller structure with an offset angle of 14° was designed based on the flow characteristics of the impeller system. The instrument was applied in simulated endodontic access cavity preparation and root canal preparation experiments. Preliminary experimental results demonstrate the feasibility of using this integrated instrument for both endodontic access cavity preparation and root canal preparation.
Chen, GuoliangXu, Kunlang
In view of the practical problem that the air-conditioner outdoor units in the spacecraft test workshops of coastal launch sites are severely damaged under the influence of super typhoon, this paper employs the finite-element simulation method to establish a finite-element model of the outdoor units. The implicit Euler solution method is used to calculate the stress conditions of each component of the unit under the influence of typhoons with wind speeds of 50.9 m/s and 61.2 m/s respectively. By combining with the material yield strength, the weak links in the design are identified, and targeted improvement measures are proposed. The simulation results demonstrate good agreement with the actual impact of the typhoon, which can effectively guide the typhoon-resistance optimization design of subsequent air-conditioning units.
Gu, YufeiChen, ShaojiangShi, YunShanFu, YuanmingChen, XiYang, Degang
Composite hollow core station post insulators utilize fiber-reinforced epoxy resin as the core rod material, offering advantages such as high specific strength, high specific stiffness, and excellent fatigue resistance. This enables them to effectively meet the flexible, variable, and complex operational demands of modern power systems. However, composite materials exhibit anisotropic characteristics, resulting in complex mechanical properties. Additionally, the core rod of hollow pillar composite insulators is typically fabricated through a spiral-plus-circumferential winding process, which significantly complicates structural design and computational analysis. This study establishes a finite element model of the hollow pillar composite insulator core rod in ABAQUS. It analyzes the influence of fiber content on composite material parameters and performs finite element numerical calculations to examine the stress state of core rods with different winding angles under compressive and bending loads. The research findings provide theoretical support for the optimized structural design of hollow pillar composite insulator core rods.
Liu, JianbiaoDu, YijunQuan, XiaoxiZhou, Songsong
This study explored the relationship between the placement roller and the radius of curvature of the mold. In the production process, it is better to judge the feasibility of placement based on the actual placement profile. It is calculated that when the prepreg with a tow width of 6.35 mm is used for automatic fiber placement and forming, the 4-tow, 8-tow, and 16-tow laying rollers can be laid at a maximum depth of 2 mm. The formulas for the length of the automatic fiber placement roller and the axial radius of curvature of the die are obtained. At the same time, through geometric analysis, a formula for calculating the minimum radius of curvature of the pressure roller is obtained. The finite element software Abaqus was used to simulate the contact of the 4-tow, 8-tow, and 16-tow laying rollers with the minimum axial critical radius of curvature at a 2 mm depth, and output the force curve of the node where the mold surface contacts the pressure roller. It is found that the simulation results are consistent with the calculation results.
Ma, ChengXiu, ZhifengXue, HongmingYang, MaoweiZhang, Pin
Based on the improved genetic optimization, a new Stewart platform optimization design method is proposed in this paper. Through introducing chaotic mapping and simulation annealing strategy, combining the kinematic analysis of the Stewart platform and the constraint conditions of the workspace, aiming at maximizing the workspace and minimizing the motion error, the structural parameters of the platform are optimized. The experimental results show that the improved GA significantly improves the workspace and motion performance of the Stewart platform compared with the traditional ant colony optimization and basic genetic optimization.
Zhu, MingWang, Baichao
Under cyclic ultra-high-pressure impact loads, structures often experience local fractures due to insufficient initial fatigue life (low-cycle fatigue). This article focused on a certain ultra-high-pressure support structure and established a dynamic model based on load transfer characteristics to simulate the transient stress-strain response under impact loads. On this basis, a low-cycle fatigue life evaluation method was used to predict the fatigue life of the structure about 362 times, which was significantly different from the required indicators for structural fatigue life. In response to the problem of high loadbearing capacity on the structural support surface and significant stress concentration at the root, the structural load-bearing method has been optimized. Calculation analysis showed that after optimization, the structural stress was greatly improved, the bearing capacity of the support surface was reduced by 25 %, and the fatigue life of the structure was increased from 362 times to 4208 times, an increase of about 10 times. The optimized structure has been verified through 2000 tests without any fracture, meeting the requirements for the service life of the structure.
Wang, ShumanNing, BianfangMa, AminZhang, Fanfan
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
In the present work, a novel method that combines accelerated solvent extraction (ASE) and gas chromatography coupled with triple quadrupole tandem mass spectrometry (GC-MS/MS) was proposed to identify and quantify polycyclic aromatic hydrocarbons (PAHs) in gasoline soot. The n-hexane was employed to extract the target analytes, and the optimal extraction conditions were identified (cycle times = 3, extraction time = 30 min, extraction temperature = 120°C, and extraction pressure = 100 MPa). The extraction efficiency of six analytes was measured to assess the ASE method; the formation mechanism of partial PAHs was discussed, and the 18 PAHs in gasoline soot were studied both qualitatively and quantitatively under the optimal conditions. It was found that our new method reached a high correlation coefficient (between 0.9987 and 0.9997); the limits of quantification (LOQs) (S/N = 6) for these PAHs were between 0.003 and 0.009 ng/mL with a relative standard deviation (RSD) of 2.9–10.6%. Our method demonstrated good performance in determining the target analytes in soot samples, such as gasoline soot, some materials soot, co-combustion soot, gasoline, and materials. The PAHs differences in soot samples containing gasoline and materials soot samples were significant enough to obtain the observed discrimination. The method is an accurate and sensitive quantitative method to identify gasoline residues in soot samples of arson fire.
Liu, ShujunCao, HenanQi, LijieLiu, YangLi, Qi
The six-degree-of-freedom Stewart platform, as a high-precision parallel robot, is widely used in fields such as aerospace and precision manufacturing. However, its complex structure and diverse sources of error (such as manufacturing errors, assembly errors, rod deformation, etc.) make it difficult to effectively control position and attitude errors. This article proposes a Stewart platform position and attitude error compensation method, relying on the improved particle swarm optimization algorithm. By establishing a position and attitude error model for the platform and optimizing the driving joint error using the IPSO optimization, the position and attitude error of the platform have been significantly reduced, providing a new solution for error compensation of high-precision parallel robots.
Zhu, MingWang, Baichao
The rotary storage mechanism is a critical component responsible for transferring cylindrical units. To accurately simulate the nonlinear dynamics characteristics of the rotary storage mechanism, a dynamics model incorporating uncertain parameters is established based on the Lagrange method. Utilizing an optimization approach, uncertain parameters of the rotary storage mechanism are identified based on test data. The Stellar Oscillation Optimization (SOO) algorithm is employed, which balances exploration and exploitation by simulating the periodic expansion and contraction of stars to achieve optimal solutions. The results show that the output of the identified dynamics model under two operating conditions closely matches the test data, validating the accuracy of the model and the effectiveness of the identification process. This provides strong support for subsequent reliability analysis and fault diagnosis studies of the rotary storage mechanism.
Li, AngChen, GuangsongHuang, PengLi, Hanning
The space cable-rod deployable articulated mast is a type of space-deployable structure with high storage efficiency. As a critical component, the pretension in the cables directly affects the stiffness and dynamic characteristics of the mast. However, research on the modeling of cable assemblies remains limited, and the relationship between cable tensions and the natural frequencies of the system has not been reported, leaving a lack of design and manufacturing guidelines for such assemblies. In this study, a dynamic model of the X-configuration cable–strut assembly consisting of a central locking device and four cables was developed, and its applicability was investigated. Guided by the characteristics of the actual structure, the assembly was simplified into a central mass–spring system, and the governing equations of motion were derived using the Newton–Euler formulation. A finite element (FEM) model based on spring elements is constructed to validate the proposed formulations. In addition, another FEM model employing beam elements is developed, and modal analyses are conducted to compare with theoretical predictions, thereby assessing the applicability of the model. The results demonstrate that the equivalent spring model can accurately capture the first, fourth, and fifth natural frequencies of the system, while its prediction of in-plane frequencies is limited due to the neglect of cable bending effects. Based on the characteristics of the three out-plane modes, explicit relationships between natural frequencies and cable tensions are derived. This work provides new insights into the simplified modeling of cable assemblies and offers valuable references for further refinement and practical applications.
Zhang, ShichengWang, YufengZhang, XiaochengSun, ChaoHe, HuadongWu, Zhiqiang
To fulfill the multi-tube launch requirements for a specific folding-wing UAV, this study improves the structure of the existing storage-launch container. Based on the finite element method, a parametric model of the container is established, and a multi-condition mechanical analysis is carried out for various storage, transportation, and launch conditions. The difference between the first six natural frequencies of the free mode and the prestressed mode is compared and analyzed. The modal analysis model considering prestress is used to identify the optimization area of the container. The variable density method (SIMP) is used to optimize the topology of the container, with the volume of the container as the constraint condition and the minimum strain energy as the optimization goal. The optimization results show that the first-order modal natural frequency of the container is increased by 108%, and the first six natural frequencies are increased to a safe range, which effectively avoids the resonance risk. At the same time, the quality is reduced by 29%, and good optimization results are achieved.
Yuan, WeiyangJi, YuguoLiu, ZhipengYu, Wenxin
This research demonstrates a facile method for fabricating an anti-icing coating through spray deposition on a metallic substrate. A dual-layer structure was designed to enhance icephobic properties: a primer layer incorporating fluorocarbon resin, butyl acetate, and rod-shaped micrometer-sized metal oxides to establish a secondary roughness morphology, followed by a topcoat composed of butyl acetate and nano-scaled superhydrophobic particles. Evaluation of the coating performance revealed a maximum water contact angle of 171.9°, indicating exceptional hydrophobicity. Furthermore, the coating exhibited notable abrasion resistance and anti-icing capabilities against overlaying ice.
Li, DongyangXu, ZelongWu, JiangTong, WeiWang, WeiqingCong, RimeiQian, JiaweiQu, Shaohui
To meet the critical need for rapid response and miniaturization in laser beam expander drive systems, this study proposes an innovative actuation solution based on a hollow rotary traveling-wave ultrasonic motor. By thoroughly analyzing the optical adjustment mechanism of laser beam expanders and the electromechanical coupling behavior of ultrasonic motors, the motor structure was systematically optimized. Using a multiphysics coupling approach, the performance of stators fabricated from three distinct materials was compared, and parametric optimization was conducted. Experimental verification confirms that the developed ultrasonic motor precisely matches the load characteristics of beam-expanding optics while fulfilling the stringent requirements for both fast response and compact design. This research provides a reference for the miniaturization drive of high-precision optical systems, with promising applications in space optics and precision instrumentation.
Qiu, HaihuiNiu, ChuanhuXiao, ZhongXu, ZhangfanLi, JialiangPan, Song
The malfunction of the aircraft windshield electric heating system, particularly arc discharge, poses a serious threat to flight safety by causing glass breakage. A systematic study was conducted on the causes and effects of arc faults on windshield structural integrity, employing macroscopic observation, microscopic analysis, and energy dispersive spectroscopy (EDS) following a windshield fracture incident. The results indicate that arc discharge typically occurs at the interface between the heating film busbar and adjacent structures. Localized high temperatures cause the outer glass to fracture, generating radial cracks. The ablation of the busbar silver coating and the carbonization of the PVB interlayer are direct evidence of arc action, whereas the heating wire remains a passive component affected by the high-temperature environment. The fault is primarily attributed to local disbonding at the busbar interface and moisture ingress. Based on the findings, recommendations are proposed for process optimization and inspection method improvement, providing a basis for the safe design and maintenance of windshield structures.
Chen, LiFeng, YanpengDing, Keqin
The propeller-driven Bernoulli adsorption device (PBD) has both propulsion and adsorption functions, being suitable for dual-mode underwater robots. Currently, there have been studies on the adsorption performance of PBD on the flat surface. However, the surface morphology of underwater engineering structures is different, and PBD’s adsorption performance on irregular walls still remains unknown. In this letter, based on the potential application scenarios of underwater dual-mode robots, we established four types of irregular wall models to investigate PBD’s adsorption performance on irregular walls. Through CFD simulations and experiments, the adsorption state was analyzed, and the adsorption performance was quantitatively studied.
Liu, SiyueHua, ZhongYang, Canjun
To further enhance the performance of the drive unit motor, a novel three-segment non-uniform Halbach array magnetic pole structure is proposed, which is applied to an external rotor permanent magnet motor with magnetic pole optimization. First, the overall motor design is carried out according to the requirements, determining the fundamental parameters of the motor. Then, four common magnetic pole structures—conventional arc-shaped, three-segment, Halbach array, and three-segment non-uniform Halbach array—are analyzed. A finite element analysis model of the motor is established for electromagnetic analysis, comparing the air-gap flux density, torque, and torque ripple of the four magnetic pole structures. Finally, optimized parameters for the stator and rotor tooth shapes are determined, and an optimization model is established. The NSGA-II algorithm is employed to optimize the stator and rotor tooth shapes. After optimization, the motor maintains its torque output while reducing torque ripple by 50%, effectively improving its performance.
Zhao, ChangleYang, Liu
Based on the principle of the bimetallic effect of the electrothermal microdrive, polymer SU-eight glue is used as the functional material, nickel metal is used as the structural material, and copper metal is used as the sacrificial layer to make the electric heating microdrive. We process and manufacture them based on specific MEMS processes such as lithography, mask plating, and magnetron sputtering, and perform basic characterization, observation, and electrical signal analysis on the samples. The results show that the overall electrothermal micro-driver device is complete, the electrode and resistance wire structure is complete, and the I-V signal is normal.
Xue, YunhaoTan, XiaolanJiang, Xin
With the continuous increase in wind turbine power capacity, ultra-long flexible blades face intensified aeroelastic instability risks due to reduced structural stiffness, enhanced modal coupling, and aerodynamic nonlinearity. In addition to the analysis of basic vibration characteristics, this study focuses on energy-related mechanisms of aeroelastic instability under various working conditions. Using a numerical model integrating Dynamic Blade Element Momentum Theory (DBEMT) and Geometrically Exact Beam Theory (GEBT), over 400 time-domain simulations were conducted to characterize instability onset and development. Results reveal four distinct aeroelastic instability regions, each dominated by specific modes. In Region A, flutter dominated by the 2nd flapwise mode is observed. In Region B, flutter dominated by the 1st edgewise mode is observed. In Region C, flutter dominated by the 2nd edgewise mode is observed. While in Region D, where the medial angle of attack (AoA) of the blade has exceeded the stall angle, stall-induced vibration dominated by the 1st flapwise mode is observed. Energy analysis shows aerodynamic work concentration near the blade tip drives instability, with diverse energy exchange patterns across regions. Except for some operating conditions in region C, where instability is dominated by edgewise energy absorption, most aeroelastic instability conditions are dominated by flapwise energy absorption. Torsional degree of freedom contributes minimally to aerodynamic work, but the torsional vibration exerts a notable influence on the AoA. This, in turn, changes the comprehensive aerodynamic forces impacting the blade as well as the general aeroelastic stability. This study clarifies the relationship between operating conditions and energy-driven instability, offering some reference values for the design work and safety assurance of ultra-long flexible blades of the wind turbine.
Wang, SuChen, JiajiaZhou, LeShen, XinLi, ChunDu, Zhaohui