最新刊期
卷 47 ， 期 10 ， 2025
- 摘要：The six-component forces at the wheel-road interaction represent the sole coupling between the vehicle and the road surface, and obtaining these forces is critical for conducting reliability and durability assessments of the entire vehicle. In response to the high cost, long cycle, and low efficiency associated with traditional methods for obtaining wheel six-component forces, a data-driven approach for rapidly predicting wheel loads was proposed. Firstly, for the non-stationary random signals on real vehicle roads, a joint method of the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), permutation entropy (PE), and wavelet threshold denoising (WTD) was applied for the data denoising. Secondly, the easily obtainable and low-cost data, such as wheel center acceleration, damper displacement, and center of mass acceleration, were used as inputs. Various neural network architectures with nonlinear transfer relationships were designed for multi-surface wheel six-component force prediction. A multi-dimensional load prediction evaluation system was established in the time domain, frequency domain, and damage domain. Finally, in order to overcome the challenges of a large and costly training dataset, an input channel compression method based on the correlation and coherence analysis of neural network inputs and outputs was proposed. Minimum load signal segment division criteria were introduced, and the minimum segment duration for each road surface was determined to compress the training dataset. Through continuous model iterations, the predicted values of the wheel six-component forces closely match the measured values, and the load characteristics are preserved. This demonstrates that the minimal dataset model can achieve a high level of prediction accuracy with fewer input channels and shorter load segment durations, resulting in a 28.85% improvement in computational efficiency.关键词：Six-component force of the wheel center;Load prediction;Neural network;Damage assessment;Fatigue durability analysis0|0|0更新时间：2025-10-31
- 摘要：Pipelines are frequently connected to power equipment such as compressors and pumps, serving critical functions including material transport and pressure transmission, thereby constituting the “highways” for material transfer in industrial production. Prolonged excessive vibration is the fundamental cause of structural fatigue damage in pipelines, detachment of instruments mounted on pipelines, and desensitization of auxiliary components. Research on pipeline vibration, noise, and their control technologies is a fundamental prerequisite for meeting industrial production requirements. Due to their significant damping effects, high reliability, and ease of installation, particle dampers are commonly employed for vibration control in industrial pipelines. However, the damping mechanisms and configuration methods of particle damping materials remain incomplete, resulting in difficulties in predicting their vibration attenuation performance. Firstly, a theoretical calculation method was developed for particle dampers used in L-shaped industrial pipelines, and the energy dissipation mechanisms of particles were analyzed under two states: “equivalent solid” and “equivalent fluid”. Then, based on variations in vibration intensity at damper installation locations, a theoretical calculation approach for particle dampers was proposed. The results indicate that under small vibration conditions without slip flow, the energy dissipation by particles can be equivalently represented by impulsive collision forces between particles and the pipeline as well as frictional energy loss; under large vibration conditions, slip flow occurs among particles exhibiting viscous damping effects. Both theoretical analysis and test results demonstrate that when particle dampers operate within an environment characterized by a reduced acceleration Γ≤3.8, collision-based damping models are appropriate to characterize their dissipative performance; conversely, when operating under reduced acceleration conditions Γ>3.8, multiphase flow frameworks should be employed to predict the vibration attenuation efficacy of particle dampers.关键词：Particle damper;Vibration reduction mechanism;Pipe;Vibration control0|0|0更新时间：2025-10-31
- 摘要：Aiming at the problem of the low fault diagnosis accuracy caused by the lack of fault samples for the rolling bearings of doubly fed wind turbines under normal conditions for a long time, an improved generative adversarial network fault diagnosis method based on expanding high-quality fault samples and using dual feature extraction was proposed. Firstly, a finite number of rolling bearing fault samples were expanded through a Wasserstein type generative adversarial network with maximum mean discrepancy and penalty constraints. Secondly, based on the dual feature extraction model, the time-frequency converted temporal features and local features were extracted separately. Finally, the fault diagnosis of the rolling bearing balance data was completed through a classifier. The standard dataset and test results show that the proposed method improves the fault diagnosis performance while lacking fault samples.关键词：Generative adversarial network;Bidirectional gated recurrent unit;Double fed wind turbine;Fault diagnosis0|0|0更新时间：2025-10-31
- 摘要：The gap between the rotor and the ball bearing in a wide temperature range increases with the increase in temperature. At the same time, the internal clearance of the bearing changes with the temperature. The inner ring of the bearing is subject to increased friction torque, which reduces its speed. This results in the deviation of the characteristic frequency of the outer ring defect, which is not conducive to the fault diagnosis of the ball bearing and the stable operation of the equipment. Considering the temperature-variable gap between the rotor and the bearing, a dynamic model of the bearing with an outer ring defect in a wide temperature range was established. The time-domain waveform and frequency of the model were analyzed. The simulation and test results show that the bearing vibration increases with the temperature, and the characteristic frequency of the outer ring defect decreases with the increasing temperature. Properly increasing the interference between the rotor and the bearing according to process requirements is beneficial for reducing the bearing system vibration in a wide temperature range and improving the accuracy of bearing defect frequency identification. The results provide reference for the use and health monitoring of ball bearings in a wide temperature range.关键词：Ball bearing;Dynamic model;Wide temperature range;Gap;Frequency deviation0|0|0更新时间：2025-10-31
- 摘要：Considering the time-varying stiffness characteristics of mechanical systems, a single-degree-of-freedom time-varying impact vibration system model with clearance stiffness was studied. The dynamic model and Poincaré map were established, and numerical calculation methods were given. The influence of the ratio of time-varying stiffness amplitudes on the dynamic response and characteristics of the system was analyzed using numerical simulation and the maximum Lyapunov exponent. By combining multiple initial value bifurcation diagrams, attraction domains, phase diagrams, and Poincaré mapping diagrams, the evolution and bifurcation of coexisting attractors in the system were studied by applying the continuation shooting method. When the bifurcation parameter changes and the system exhibits the coexistence phenomenon, the reasons for the appearance and disappearance of local attractors and the distribution mechanism of unstable attractors in the attraction domain before and after bifurcation are revealed. The stability change rule of coexisting attractors is obtained.关键词：Time-varying stiffness;Vibration system;Coexistence attractor;Stability;Bifurcation0|0|0更新时间：2025-10-31
- 摘要：A fault diagnosis method based on improved dung beetle optimizer (IDBO)-time varying filtered empirical mode decomposition (TVFEMD) with improved wavelet threshold functions was proposed aiming at that the vibration signal of rolling bearing fault tends to be disturbed and overwhelmed by strong noise background. IDBO was primarily developed to iteratively optimize B-spline order and bandwidth threshold
- 摘要：Rolling bearing looseness faults are likely to induce transmission system fault. Considering the factors such as nonlinear contact force of rolling bearings, rub-impact force, damping force between outer ring and housing, a six-degree-of-freedom nonlinear dynamics model was established under the fault of rolling bearing outer ring looseness, and the vibration characteristics of rolling bearing outer ring looseness were analyzed. The simulation results show that the characteristic frequency of the outer ring looseness fault is presented as the rotational frequency of the rotating shaft and its multiple components, and the actual tested wind power bearing ring fault data verifies the accuracy of the model. The results of this paper show that the rolling bearing outer ring looseness is caused by loosing between the outer ring and the housing, and the cyclic impact and friction between the outer ring and housing are formed under the unbalance force with the rotational speed of the shaft and its harmonics. The research results provide a theoretical basis for realizing the mechanism analysis of rolling bearing outer ring looseness and fault diagnosis of the rolling bearing.关键词：Rolling bearing;Outer ring looseness;Dynamical model;Fault characteristic0|0|0更新时间：2025-10-31
- 摘要：Abnormal yaw positioning during yaw operations induces progressive deviation in yaw alignment accuracy, thereby compromising wind-tracking precision and risking excessive cable twisting that threatens operational safety. Concurrently, frequent position oscillations or repetitive short-duration position holding generate transient control errors, destabilizing the yaw control system. These coupled mechanisms collectively escalate yaw system failure frequency and operational maintenance costs. To proactively mitigate these risks, a data-driven fault diagnosis methodology is proposed for early detection of anomalous yaw positioning in wind turbines. Firstly, a large amount of data in a supervisory control and data acquisition (SCADA) system was processed using a standardized interaction gain and Relief-F (SIG-Relief-F) feature selection algorithm to identify multiple feature parameters with the strongest correlation with the target variable (which in this case may be yaw system failure). The advantage of this method lied in its ability to consider effectively the correlation between features, thus maximizing the retention of relevant features related to yaw system failures and interaction features. Secondly, a back propagation neural network (BPNN) yaw position prediction model was established, and the distribution of residuals was statistically analyzed using a sliding window method to determine the fault threshold. Finally, through empirical verification, the effectiveness and accuracy of the proposed method were demonstrated, and compared with multivariate state estimation technique (MSET) and support vector machine (SVM) algorithms, it was shown to have superior abnormal warning performance. The conclusions drawn can serve as a reference for the fault diagnosis of a practical yaw system.关键词：Wind turbine;Yaw position;Interactive information;Relief-F;BPNN;Abnormal warning0|0|0更新时间：2025-10-31
- 摘要：In order to achieve simulation prediction of the isolation performance of rubber isolators, simulation and testing comparative research on the vibration transmissibility of standard specimens were conducted. Firstly, a compression test was conducted on the standard specimen to obtain pressure deformation data. Based on the theory of the large deformation, the data was processed to obtain the true stress-strain curve. The Mooney-Rivlin model was chosen to define the material properties. Secondly, a vibration transmissibility testing system was established, an exciter to excite the standard sample was used, and the measured vibration transmissibility curve was obtained. Then, a simulation model based on the testing system was built, and the simulation transmissibility curve based on the transient dynamic analysis was obtained. Finally, the test results were compared with the simulation results to achieve the simulation prediction of the rubber isolation performance. The results show that the simulated isolation rate curve is highly consistent with the test results, with a peak frequency error of only 4.8%, which can achieve the simulation prediction and provide a simulation guidance for the optimization design and performance improvement of isolators.关键词：Rubber isolator;Non-linear;Transient dynamics;Vibration transmissibility;Simulation prediction0|0|0更新时间：2025-10-31
·Vibration·Noise·Monitoring·Diagnosis·
- 摘要：A set of anti-impact protection device was designed for the test fracture accident of 30 MN tension sensor calibration device. Firstly, based on the kinematic theory, the kinematic model of each component in the fracture process of test fixture was established. Then, different protective device structures at three impact locations were designed. Finally, the finite element models of three buffer structures were established and verified, calculated and optimized. The results show that the egg-box structure protection device at the top plate of the upper reaction rack and the upper ball joints can effectively solve the problems of small protection space and large impact value. The whole device dissipates 59.5% impact kinetic energy of the upper reaction rack, 60.7% impact kinetic energy of the lower reaction rack and 100% impact kinetic energy of the lower ball joints. After the improvement, the initial peak load of the protective device at the lower ball joints is reduced by 62.7%.关键词：Fracture impact;Super-large force value standard machine;Protective device;Egg-box structure;Finite element simulation0|0|0更新时间：2025-10-31
- 摘要：The influence of different multi-delamination forms on the tensile strength of blade spar cap laminates was studied. Static tensile tests were conducted on laminates with single and multiple delaminations. The continuous damage model (CDM) and cohesive zone model (CZM) were used to analyze the damage process and failure mode. The numerical results showed good agreement with test values, with an overall error rate below 7%. A numerical model of 1.5 MW-40.3 m blade spar cap equivalent laminates was established to predict the effect of different types of multi-delamination on the tensile strength. The results show that the arrangement, maximum area, and step difference of delaminations all have an impact on tensile strength. The tensile strength of triangular multi-delamination is higher than that of inverted triangular multi-delamination laminates, and the maximum delamination near the surface greatly affects the tensile failure load.关键词：Multiple delaminations;Wind turbine blade;Spar cap;Numerical simulation;Tensile strength0|0|0更新时间：2025-10-31
- 摘要：The aircraft’s inlet structure is connected to the engine sleeve using countersunk rivets. During maintenance, fatigue fractures were discovered in some rivets. It suggests that the inadequate perpendicularity of rivet holes during manufacturing causes the rivet misalignment, reducing the load-bearing capacity, and leading to fatigue fractures under aircraft vibrations. The finite element simulation was used to study the effect of inclined rivet holes on the load-bearing capacity, simulation results show that inclined holes cause uneven stress distribution across the rivet section. The higher the tilt angle, the higher the maximum stress and the more uneven stress distribution on the rivet head section. Fatigue tests under axial loads at different tilt angles demonstrated a reduction in the rivet’s fatigue life due to the hole inclination. The study concludes that non-compliance with perpendicularity standards during hole fabrication results in uneven stress distribution, decreasing load-bearing capacity. Therefore, the strict control over rivet hole perpendicularity during the aircraft manufacturing is crucial to ensure structural reliability.关键词：Rivet;Drilling verticality;Stress distribution;Fatigue life;Finite element simulation0|0|0更新时间：2025-10-31
- 摘要：In view of the problem that the formulary design load based on the design standard can't truly reflect the actual service conditions of the welded frames of subway vehicles, and a large number of online measured data information has not been fully explored in the structural design of the frame, an anti-fatigue design spectrum compilation method based on the stress-time history sample information measured at the weak position of the subway vehicle frame was proposed.The small stress threshold value was determined by clustering ordered samples using the rain-flow counting method to compile measured stress spectrum reflecting structural damage, determining the stress-frequency-damage relation based on the fatigue damage theory, and using the methods of Bayesian parameter estimation and kernel density estimation to obtain stress extrapolation results. Considering the stress concentration caused by structural geometry changes in the cross-section of the welding site, the hot spot stress method and stress linearization method were used to obtain the stress concentration coefficient, and the measured stress spectrum was corrected to achieve the compilation of the design load spectrum. The research results show that the small stress threshold value is 3.18 MPa determined by extrapolation of stress extremes and the relation analysis between normalized stress-frequency-damage, which is 8.19% higher than the stress threshold value determined by traditional methods, the effect of discarding the number of small stress cycles is significant. Considering the load dispersion and stress concentration factor at the weld seam, while ensuring that the structure meets the current service conditions, the relation between the design mileage and equivalent stress is determined, the necessity of compiling the design spectrum is emphasized further. The above research builds the construction method of load spectrum compilation and the equal strength design of structures.关键词：Frame;Stress spectrum;Damage equivalence;Stress concentration;Design spectrum0|0|0更新时间：2025-10-31
- 摘要：To enhance the energy absorption efficiency of conventional sandwich panels, a biomimetic tree-like fractal core (BTLFC) inspired by the dendritic fractal structure of the royal lotus leaf vein was designed. Firstly, quasi-static compression tests revealed that the 2-order BTLFC exhibited a specific energy absorption 5.69% higher and an average load 4.46% greater than traditional honeycomb cores. Secondly, a finite element numerical model of the BTLFC was established; combined with quasi-static compression test data, the finite element model error was within 2.2%, demonstrating high accuracy of the model. Finally, Latin hypercube test design, Kriging surrogate model, and the non-dominated sorting genetic algorithm-II (NSGA-II) were employed to perform multi-objective optimization on the structural parameter combinations of the BTLFC (size ratio r, bifurcation angle θ, fractal order D). The optimized BTLFC structure exhibited superior comprehensive performance, with specific energy absorption increased by 10.19%, peak crushing force reduced by 12.27%, and mass decreased by 11.79% compared to traditional honeycomb cores. The findings provide novel biomimetic design insights for developing high-performance energy absorption structures.关键词：Leaf vein structure;Biomimetic design;Finite element;Energy absorption;Multi-objective optimization0|0|0更新时间：2025-10-31
- 摘要：To evaluate the performance of various equivalent stress intensity factor models in predicting mixed-mode fatigue crack growth and to address the challenge of parameter estimation under limited sample conditions. A crack growth parameter estimation method based on the Bootstrap method resampling technique was proposed firstly. Mode Ⅰ fatigue crack growth tests were conducted on CT specimens to obtain the material parameters, and the proposed method was employed to expand the sample set and mitigate the issue of data scarcity. Then, using the statistically augmented material parameters, mixed-mode Ⅰ+Ⅱ fatigue crack growth experiments were performed on 6005A-T6 aluminum alloy CTS specimens under loading angles of 0°, 30°, 45° and 60°, employing a Richard-type loading fixture, to validate the accuracy of various equivalent stress intensity factor models. The results indicate that the Irwin model achieved the highest goodness-of-fit, with a value of 0.942 1, demonstrating the best crack growth prediction performance. Increasing the loading angle was found to reduce the initial crack growth rate, highlighting the need for angle-specific experiments to obtain appropriate Paris law parameters. This study confirms the applicability of multiple ΔKeq models and provides theoretical support for fatigue life prediction in mixed-mode crack growth scenarios.关键词：Aluminum alloy;Mixed-mode crack;Equivalent stress intensity factor;Bootstrap method;Local displacement field2|0|0更新时间：2025-10-31
- 摘要：To enhance the computational efficiency of structural lightweight design for complex structures, a structural lightweight design method based on the Kriging surrogate model is proposed. The proposed method incorporates a hybrid addition strategy and a sample deletion strategy considering a distance threshold， aiming to rapidly improve the fitting accuracy of the Kriging surrogate model. This model was then applied to a multi-objective lightweight design model of the truck frame, with the optimization objectives of minimizing frame mass and maximum stress. Subsequently, the multi-objective lightweight model was solved using the non-dominated sorting genetic algorithm-II (NSGA-II). The results demonstrate that the proposed hybrid addition strategy and sample deletion strategy considering the distance threshold effectively enhance the update process of the Kriging surrogate model. The structural lightweight design method based on the Kriging surrogate model exhibits significant advantages in both computational efficiency and lightweight performance.关键词：Structural lightweight;Truck frame;Kriging surrogate model;Hybrid addition strategy2|0|0更新时间：2025-10-31
- 摘要：To address the issue of damage caused by low-speed impacts on composite material laminates coated with polyurethane coating, a numerical analysis method based on three-dimensional progressive cumulative damage in composite laminates and a yield damage criterion for polyurethane coatings was proposed. Firstly, a damage numerical model of polyurethane coating-carbon fiber reinforced composite laminates under erosion was established, and a Vumat subroutine was written. Subsequently, referring to the ASTM D7136 test standard, impact tests with various energy levels were conducted on samples coated with 1 mm and 2 mm polyurethane coatings and uncoated samples. Simultaneously, the proposed damage model was employed to study the formation reasons and propagation patterns of primary damages such as fiber damage, matrix damage, and delamination, thereby revealing the mechanism of polyurethane coating in absorbing impact energy. The results indicated that the mechanical response results calculated by the proposed damage model showed a high degree of agreement with the test results, validating the correctness of the proposed model. Additionally, comparative tests demonstrated the enhancement effect of polyurethane coating on the impact damage resistance of carbon fiber composite laminates. The findings of this study can provide a reference for the design of protective coatings for aircraft.关键词：Composite materials;Polyurethane coating;Predictive model;Impact testing;Damage mode2|0|0更新时间：2025-10-31
·Experimental Research·Testing Technology·
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