最新刊期
卷 47 ， 期 12 ， 2025
- 摘要：Ti6Al4V ELI titanium alloy is widely used in important structures of deep-sea manned equipment due to its excellent mechanical properties. However, during deep-sea service, manned equipment is continuously subjected to complex fatigue loads, which can easily lead to crack initiation and propagation, and in extreme cases, may even lead to catastrophic rupture accidents. Crack initiation is a key factor in determining the overall fatigue life, and accurate prediction of it is essential to ensure the safety of the equipment. Although existing fatigue life analysis methods have been able to reveal the fatigue behavior characteristics of Ti6Al4V ELI titanium alloys to a certain extent, their accuracy is still insufficient when predicting the life of materials with different microstructures. To solve this problem, a realistic microstructure model was reconstructed using electron back scatter diffraction (EBSD) technology, the numerical simulations were conducted based on the crystal plasticity finite element method, and a fatigue crack initiation life prediction model for Ti6Al4V ELI titanium alloy was successfully established. The low-cycle fatigue behavior of dual-phase structured Ti6Al4V ELI titanium alloy was simulated, and two fatigue indicator parameters (FIPs), cumulative plastic slip and cumulative energy dissipation, were introduced to comprehensively assess the extent of damage during fatigue. The results show that the fatigue damage is mainly concentrated in the regions with severe plastic slip and high energy dissipation, especially at the interface location between the α-phase and β-phase. In addition, the tensile asymmetry within the grains leads to lattice rotation, which further exacerbates strain localization and accelerates the evolution of microstructure. By comparing with the experimental lifetime data, it is found that the lifetime prediction method based on cumulative plastic slip exhibits higher accuracy compared with the lifetime prediction method based on cumulative energy dissipation. Meanwhile, the fatigue indicator parameter-based prediction method better reveals the variability of the life of Ti6Al4V ELI titanium alloys with different microstructures compared with the conventional Coffin-Manson (C-M) model. This study not only provides new ideas and methods to improve the accuracy of fatigue crack initiation life prediction for Ti6Al4V ELI titanium alloy, but also provides strong support for the safety and reliability of this material in practical applications.关键词：Crystal plasticity;Fatigue indicator parameter;Crack initiation;Fatigue life prediction;Titanium alloy3|0|0更新时间：2025-12-22
- 摘要：Structural health monitoring (SHM) plays a crucial role in ensuring infrastructure safety, extending service life, and reducing maintenance costs. However, existing monitoring methods usually rely on sensor data and traditional physical models, which exhibit certain limitations when addressing problems such as complex mechanical behaviors, environmental change, and data scarcity. As an emerging deep learning approach, physics-informed neural network (PINN) integrates physical laws with data-driven characteristics, offering a novel pathway to overcome the constraints of conventional methods. Firstly, the methods that incorporate the physical principles into machine learning frameworks and the effectiveness of these methods in structural health monitoring were thoroughly discussed. Secondly, multiple approaches for integrating physical knowledge with machine learning models were discussed, highlighting their respective advantages and limitations. Finally, the application of PINN in SHM was comprehensively reviewed, particularly their potential in damage identification, crack propagation analysis, and life prediction. Compared to traditional methods, PINN demonstrates significant advantages in handling complex structural problems. In the training process of embedding physical equations (e.g. mechanical governing equations) into the neural network, PINN not only effectively handles the problems of data scarcity and overfitting, but also improves the accuracy and reliability of structural health assessments.关键词：Physics-informed neural network;Structural health monitoring;Crack;Fatigue assessment method;Review2|0|0更新时间：2025-12-22
- 摘要：Titanium alloys are widely used in industrial fields such as aerospace, energy and chemical engineering due to their outstanding comprehensive properties. With the development of industrial technology, higher requirements have been put forward for the creep strength of titanium alloys. In order to improve its creep resistance, a lot of work has been carried out, but so far, the work is relatively scattered and lack systematic sorting and summary. In response to this issue, the research work on the creep resistance of titanium alloys in recent years was summarized and concluded. The research progress on the creep strength of titanium alloys was summarized from four aspects: alloy elements, microstructure, room temperature creep, and creep models, aiming to provide basis and scientific guidance for the design, preparation, and improvement of creep resistance of titanium alloys.关键词：Titanium alloy;Anti creep performance;Alloy element;Microscopic structure;Creep model2|0|0更新时间：2025-12-22
- 摘要：The flexible multi-stranded wire structure is widely used in industrial fields such as bridges, buildings, coal mines, and power transmission due to its many advantages such as good flexibility, high reliability, and high strength. The service environment of the stranded wire structure is complex, and it is subjected to loads such as tension, torsion, bending, and multi-axis combined loads composed of them in a long time. The wind load, rain load, snow load, current, etc. they are subjected to can easily cause fretting damage between the stranded wire and the wire clamp, as well as between the stranded wire strands. The fretting damage of the multi-stranded wire structure usually manifests as an increased probability of broken wires and strand, leading to consequences such as increased losses in the stranded wire, decreased conductivity and shortened fatigue life. Severe fretting damage may even cause rapid fracture failure of the stranded wire. Aimed at the fretting damage of the flexible multi-strand wire structure in the engineering, firstly, the current research status at home and abroad was outlined, the damage form was clearly defined. Subsequently, the contact characteristic analysis was conducted, the influencing factors were summarized, the relevant test apparatus was listed, and then the prediction and protection strategies were introduced. Finally, an appropriate outlook was made aiming at the research progress in current of fretting damage of the flexible stranded wire structure.关键词：Flexible strand structure;Fretting damage;Test device;Damage protection7|21|0更新时间：2025-12-22
- 摘要：Focusing on the stress concentration problem of V-notches, considering the actual measured surface morphology and geometric profile, the impact on stress concentration was studied based on finite element methods. By applying the notch superposition effect, the measured surface morphology and geometric profile were incorporated into notch. Relative to smooth theoretical V-notch dimensions, the formulas of stress concentration factor (SCF) and relative stress gradient(RGS) were modified. which were validated through simulation using multiple sets of measured morphology and dimension data. Analysis of variance was employed to investigate the influence of surface morphology and geometric profiles on the stress concentration factor and relative stress gradient. The results show incorporating measured geometric profiles more accurately assesses stress concentration factors and measured surface topographies more accurately assesses relative stress gradients. Additionally, smaller notch dimension and rougher surface morphology increase stress concentration.关键词：V-notch;Surface morphology;Geometric profile;Stress concentration;Relative stress gradient2|0|0更新时间：2025-12-22
- 摘要：To investigate the fatigue damage of axles in a certain type of high-speed EMU, a vehicle-track rigid-flexible coupled dynamic model and a wheel set finite element analysis model were employed to analyze the crack propagation behavior of axles under the combined effects of wheel flat and axle impact damage. The influence of different train speeds and varying wheel flat sizes on the residual life of the axle was studied. The results indicate that the residual life of axles with impact damage is closely related to the train speed and the size of the wheel flat. When both wheel flat and axle impact damage coexist, there exists a critical speed corresponding to the wheel flat at which the residual life of the axle is minimized. If the train speed remains constant, the residual life of the axle decreases rapidly with the increase in wheel flat size. At a train speed of 300 km/h, with a wheel flat length of 30 mm and the presence of axle impact damage, the residual life of the axle is 583 700 km, which is close to the interval for a Level 3 maintenance cycle and requires corresponding treatment according to regulations.关键词：Axle fatigue;Crack;Wheel flat;Impact damage;Residual life;Extended finite element2|0|0更新时间：2025-12-22
- 摘要：The high-speed circuit breaker is an important device to ensure the safety of train circuits, which controls the connection and disconnection of the circuit via opening or closing the moving and static contact terminal. It is an important basis to study the remaining life of the contact terminal for the operation and maintenance of circuit breakers. However, there is no systematic work being reported yet. Therefore, test scenarios were built that matched the operation and maintenance conditions of circuit breakers, and established a residual life model of circuit breakers based on test data. The contact terminal of high-speed circuit breakers in Chengdu Metro subway vehicles was taken as the research target, and then its evolution law of the remaining life in daily service conditions was studied by using a combination approach that comprises finite element simulation and test investigation, which was to study the variation rule of the thickness of the silver-plated layer thickness of the contact terminal with the number of uses. The numerical simulation results show that the stresses in moving and static contact terminals are less than the material fatigue limit, and the fatigue service life of both types of contact terminals is considered to be an infinite life level in the safety life assessment. Moreover, the test results show that the coating thickness of the moving contact terminal decreases with the increase of test cycles, yet the reducing thickness is mainly due to the wear caused by the grinding process such as bias grinding. Based on the linear prediction model, the remaining life of the moving contact terminal was evaluated, and the calculation results show that when the coating thickness of the moving contact terminal reduced from the initial 3.003 mm to the limit of 1.5 mm, the circuit breaker contact can be used for 19 313 cycles, corresponding to the natural year about 36.2, which is about 2.4 times of design service life. The predicted value has been verified by hypothesis testing, and the calculated result is within the predicted interval. The above research results are expected to provide relevant support for the development of maintenance intervals and maintenance strategies for contact terminals.关键词：Subway vehicle;High-speed circuit breaker;Contact terminal wear;Numerical simulation;Test study;Remaining life56|61|0更新时间：2025-12-22
- 摘要：Lattice sandwich structures possess excellent mechanical properties such as high specific strength, impact resistance,and noise reduction, which are widely used in construction, vehicles and ships, aerospace,and other fields. In the design of such engineering structures, it is crucial to improve the acoustic isolation performance of the structure to reduce noise. Due to the large number of fine-scale components in the lattice sandwich structures, detailed finite element numerical analysis of these structures entails a significant computational workload, generally necessitating their equivalence to homogeneous structures for structural response analysis. Firstly, a theoretical model was established for sound transmission loss (STL) of lattice sandwich structures under the condition of vertical incidence of simple harmonic acoustic waves. The novel implementation of the asymptotic homogenization method (NIAH) was briefly described, and the feasibility of calculating STL of lattice sandwich structure was analyzed based on this method. On this basis, the STL of the reinforced honeycomb lattice sandwich structure unit cell was predicted using the asymptotic homogenization method. Meanwhile, an acoustic analysis model of the structure was established in finite element software, and the reliability of the theoretical calculation was verified by comparing the STL curves of the structure. Finally, the effects of key parameters such as panel thickness and core layer size on the acoustic isolation performance of the reinforced honeycomb lattice sandwich structure were discussed. The results of the study provide reference for the acoustic performance analysis of lattice sandwich structures.关键词：Asymptotic homogenization method;Lattice sandwich structure;Sound transmission loss;Reinforced honeycomb;Acoustic isolation performance2|0|0更新时间：2025-12-22
- 摘要：A new PSO-GWO composite algorithm is proposed for the qualitative and quantitative detection of damage in layered composite materials, integrating traditional particle swarm optimization (PSO) algorithm and grey wolf optimization (GWO) algorithm. Construct a new objective function for solving damage detection problems using three identification accuracy indicators:modal flexibility matrix, frequency, and mode shape. Based on the characteristics of two traditional optimization algorithms, a nonlinear convergence factor was adopted to balance the local search ability and global search ability of the algorithm; add an adaptive local search strategy to increase the diversity of the algorithm iteration process; introducing a multi-level guided iteration strategy of the grey wolf algorithm, combined with the speed update strategy of particle swarm optimization, to compensate for the algorithm's tendency to fall into local optima. The detection results of three different types of laminated panels show that the PSO-GWO composite algorithm has advantages in detection accuracy and convergence speed, and can achieve accurate identification of the location and degree of damage.关键词：Damage detection;Composite material;Particle swarm optimization algorithm;Grey wolf optimization algorithm;Modal parameter2|0|0更新时间：2025-12-22
- 摘要：Based on the Gurson-Tvergaard-Needleman (GTN) damage model, the coalescence behavior of double elliptical cracks with different sizes and the coalescence criterion based on crack spacing ratio was studied in homogeneous plates with elliptical double cracks. The results show that there is an obvious dividing line between the crack coalescence region and the non-coalescence region in the coordinate system based on the crack spacing ratio. The rigon below and on the boundary line corresponds to the coalescence of double cracks, while the region above the line corresponds to the non-coalescence of double cracks. Based on the crack spacing ratio, the coalescence criterion of double elliptical cracks can be established.关键词：Coalescence criterion;Double elliptic cracks;Crack spacing ratio;GTN model;Homogeneous plate2|0|0更新时间：2025-12-22
- 摘要：To address the inefficiency in extracting bolt stress data during the creep process and the complexity of the bolt strength verification procedure, an automated bolt verification platform was developed. Firstly, a finite element model for creep analysis of the engine block and cylinder head bolt connection structure was established in Abaqus. Based on the finite element analysis results and the VDI 2230 theory， bolt strength verification was conducted. The platform integrates the formulas, algorithms, and database for bolt verification as stipulated in the VDI 2230 theory. Subsequently, different modules of the platform enable automatic extraction of bolt finite element results, automatic bolt strength verification, and automatic generation of corresponding bolt verification reports through the execution of CAE secondary development scripts. The results indicate that after creep occurs in the engine block and cylinder head, all safety factors of the cooperating cylinder head bolts comply with the standards.关键词：Bolted joint;Creep relaxation;VDI 2230 theory;Secondary development of CAE;Checking platform1|0|0更新时间：2025-12-22
·Fatigue·Damage·Fracture·Failure Analysis·
- 摘要：Negative Poisson ratio materials are widely used in various fields because of their unique properties of expansion in tension and contraction in compression. A honeycomb material with negative Poisson ratio was obtained by equal biaxial compression of the two-dimensional Voronoi model, and the effects of different compression ratios on their static tensile/compressive mechanical properties were studied by numerical simulation. The results show that the tensile and compressive stress-strain curves of the two-dimensional negative Poisson ratio honeycomb prepared by the above methods have typical “three-stage” deformation characteristics of porous materials, and show significant tensile and compressive strength asymmetry. Under uniaxial tension, the material shows the obvious negative Poisson ratio phenomenon. With the increase of the compression ratio, the modulus of elasticity and elastic Poisson ratio gradually decrease, and the yield strength and platform stress gradually increase. With the gradual increase of the tensile strain, the plastic Poisson ratio of the material changes from negative to zero and then to positive. However, due to the mutual contact between the inner edges of the material, the inward deformation of the material is limited. Therefore, the material exhibits positive Poisson ratio behavior under uniaxial compression, and its modulus of elasticity, yield strength, elastic/plastic Poisson ratio and platform stress increase with the increase of the compression ratio. In addition, the negative Poisson ratio material is anisotropic in the tension and isotropic in the compression.关键词：Negative Poisson ratio honeycomb;Deformation mode;Elastic/plastic Poisson ratio;Plateau stress;Tension-compression asymmetry63|169|0更新时间：2025-12-22
- 摘要：To investigate the effect of three-body particle invasion on the friction noise of friction pairs, a friction testing machine for the test research was constructed. Data was collected through a noise acquisition analyzer, and the impact of three-body particles on the friction noise of the disc block friction pair was analyzed. Simultaneously the friction force signal of the friction pair was collected to explore whether there is an inherent relation between the friction force and friction noise of the friction testing machine under frictional parameters (such as speed and pressure). The test results show that under different pressures, the friction noise first increases and then decreases with the increase of rotational speed. After the invasion of three-body particles, the friction noise significantly increases, but the overall trend is consistent with that of two-body friction. Friction noise is directly proportional to friction force. Certain reference value for the analysis of the noise characteristics of braking systems under the invasion of three-body particles is supplied.关键词：Friction noise;Particle invasion;Braking system;Friction characteristic1|0|0更新时间：2025-12-22
- 摘要：Plate lattice metamaterials are an emerging class of multifunctional metamaterials characterized by exceptional physical and mechanical properties. Specimens of fluorite structure plate lattice metamaterials with varying cell lengths, wall thicknesses, pore radius, and numbers of cell layers were fabricated using fused deposition modeling 3D printing technology. Quasi-static compression tests were conducted on the fabricated specimens, and their deformation mechanisms were analyzed and compared through digital image correlation and finite element simulations to investigate the effects of different parameters on the mechanical performance and energy absorption capabilities of the fluorite structure plate lattice metamaterials. The study revealed that the fluorite structure without holes exhibits higher modulus of elasticity and yield stress within the elastic region, demonstrating superior deformation resistance. Although energy absorption efficiency increases with cell length, the specific energy absorption decreases. Increasing wall thickness results in higher modulus of elasticity and platform stress but reduces specific energy absorption. Enlarging the pore radius leads to decreases in platform stress and energy absorption, as well as a reduction in specific energy absorption. The specific energy absorption reaches its maximum when the number of cell layers increases to three; however, excessive layering diminishes energy absorption efficiency.关键词：Plate lattice metamaterial;Fluorite structure;Fused deposition modeling;Mechanical property0|0|0更新时间：2025-12-22
- 摘要：Precision reducers，as one of the core components of industrial robots, have long been a research focus in the robotics field.Therefore, from the perspective of structural innovation, a new type of precision worm gear reducer suitable for industrial robots was proposed in this paper.By addressing the shortcomings of high relative sliding speed and large meshing clearance in traditional worm gear transmission, a 3D model of the reducer was established using SolidWorks software. Subsequently, strength verification，modal characteristic analysis, and transmission principle analysis of the reducer were conducted using Ansys Workbench software and Adams software.Through these analyses, the transmission error spectrum of the reducer was obtained, and the influence of different parameters on the load sharing coefficient was analyzed.A prototype reducer was manufactured according to the design parameters, and various performances of the prototype were tested on an integrated test bench for robot reducers; the test results were compared with those of theoretical calculations and simulation analyses.The results showed that the structural design and transmission principle of the developed precision worm gear reducer were reasonable, with a transmission accuracy of 40.13" arcseconds and a backlash of 0.47', and it operated stably.关键词：Industrial robot;New type of worm gear reducer;Structural design;Simulation analysis;Prototype testing0|0|0更新时间：2025-12-22
·Experimental Research·Testing Technology·
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