Home
|
About Journal
|
Editorial Board
|
Instruction
|
Subscriptions
|
Contacts Us
|
中文
Office Online
Submission Online
Peer Review
Editor Work
Editor-in-chief
Office Work
Journal Online
Accepted
Current Issue
Advanced Search
Archive
Read Articles
Download Articles
Email Alert
Quick Search
Adv Search
2026 Vol. 47, No. 1
Published: 2026-02-25
1
Research Progress in Machine Learning-Based Prediction of Fatigue Property for L-PBF Ti-6Al-4V
Ti-6Al-4V alloy fabricated by laser powder bed fusion (L-PBF) holds significant promise in aerospace applications due to its superior specific strength and good corrosion resistance. However, the unique manufacturing process inevitably introduces complex internal defects, such as pores and lack of fusion, alongside metastable microstructures. These factors cause significant scatter in fatigue performance, making it challenging for traditional physical models to accurately map the nonlinear relationships along the "process—structure—property" chain. Consequently, Machine Learning (ML) has emerged as a robust data-driven approach to address these challenges. This paper provides a comprehensive review of the research progress in ML-based fatigue property prediction for L-PBF Ti-6Al-4V. First, critical influencing factors—including defect characteristics (size, location, and morphology), microstructure, surface roughness, and residual stresses—are systematically analyzed to establish a physical basis. Then, for deterministic fatigue life prediction, this paper introduces three main streams: feature engineering-based data-driven methods, which rely on manually crafted descriptors; microscopy image-based deep learning methods, which automatically extract features from raw image data; and physics-informed ML models, which integrate domain knowledge to enhance interpretability and extrapolation capability, especially with small datasets. Beyond deterministic prediction, the main ML approaches for quantification of fatigue performance uncertainty are explored. Techniques such as Bayesian Neural Networks (BNN), Dropout NN, and Gaussian Process Regression (GPR) are evaluated, specifically analyzing their strengths and limitations in decomposing and quantifying both aleatoric uncertainty (from material intrinsic randomness) and epistemic uncertainty (from model/knowledge limitations). Through this analysis, several persistent challenges are identified, including data scarcity, the lack of interpretability in complex models, and the difficulty of modeling multi-factor coupling. Finally, promising future directions are outlined. These include fostering open data platforms to alleviate data bottlenecks, advancing hybrid modeling that deeply integrates physical mechanisms, and promoting the transition of ML models from lab research to integrated digital twin platforms for in-situ quality monitoring and component-level life prediction. This paper aims to provide a methodological reference and highlight a clear path toward more reliable and industrially applicable fatigue life prediction for additively manufactured titanium alloys.
2026 Vol. 47 (1): 1-33 [
Abstract
] (
5
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
34
Analysis of influencing factors on the shakedown limit of three-dimensional wheel-rail rolling contact
The shakedown limit defines the critical load preventing sustained alternating plasticity or ratcheting deformation in elasto-plastic structures subjected to cyclic loading. This provides a vital theoretical guidance for improving rail load-bearing performance and optimizing design against rolling contact fatigue. However, previous shakedown analysis models neglect the temperature-dependent material properties, non-linear cyclic hardening behavior, stick-slip frictional regime, and non-Hertzian contact conditions arising from the complex wheel/rail tread surface and wheelset lateral motions. Consequently, they exhibit significant deviations from the actual service conditions of rails. Therefore, the standard wheel/rail tread geometry and a modified Abdel Karim-Ohno cyclic plasticity constitutive model with temperature-dependent elasto-plastic material properties are employed here. Moreover, the strip theory is applied to determine the tangential traction under partial stick/slip rolling contact conditions. The finite element simulations of three-dimensional cyclic elasto-plastic rolling contact of rails are performed to obtain the evolution of equivalent plastic strain with the loading cycle. And then, a shakedown criterion is developed to identify the rail’s shakedown state in combination with the fundamental shakedown definition. A bisection iteration of axle loads is implemented to search for the shakedown limit corresponding to the critical shakedown/non-shakedown condition. Parametric studies are conducted based on the developed model to examine the effects of wheelset lateral motion, creepage mode, and temperature dependence of elasto-plastic properties on the shakedown limit. Results show that wheelset lateral motion reduces the contact pressure, suppresses the plastic deformation, and consequently increases the shakedown limit, though this effect becomes slight under low friction coefficients with an opposite-direction motion; decreasing the normalized tangential loading coefficients expands the stick zone, reduces the tangential traction and total contact stress, weakens the plastic deformation, and thereby elevates the shakedown limit, particularly under high-friction conditions; a thermo-induced decrease in elastic modulus enhances the shakedown limit by reducing the structural stiffness and contact stress level, whereas the thermal decay of both isotropic resistance and hardening modulus promotes the plastic deformation and then reduces the shakedown limit.
2026 Vol. 47 (1): 34-51 [
Abstract
] (
5
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
52
Molecular dynamics simulation study on the plastic behavior of single-crystal nickel under different nanoindentation speeds
The plastic behavior of single-crystal nickel critically governs its reliability and lifespan in aerospace and micro/nano-manufacturing applications. Consequently, understanding its plastic response and microscopic deformation mechanisms under localized indentation is essential for providing mechanistic and engineering guidance. In this study, molecular dynamics simulations are employed to investigate the spherical nanoindentation of single-crystal nickel, focusing on the influence of dislocation reactions on early-stage plastic deformation mechanisms. The study further examines the regulatory role of indentation speed on load drops and work-hardening behavior, while elucidating the intrinsic correlation between dislocation reactions and load drop phenomena. Results demonstrate that during the initial load drop stage, the propagation of Shockley partial dislocations on {111} slip planes forms semi-closed dislocation loops and intrinsic stacking faults, which triggers the first load drop. Increasing the indentation speed significantly alters dislocation evolution characteristics. Specifically, under low indentation speeds, dislocations organize into ordered V-shaped slip bands, whereas high indentations speeds promote the formation of disordered networks. Moreover, the indentation depth corresponding to the initial load drop increases with increasing speed. The work-hardening behavior exhibits pronounced rate dependence: under low indentation speeds, stable high-density dislocation networks form through Lomer-Cottrell locks and Hirth locks, whereas high speeds induce loose dislocation configurations due to non-equilibrium responses, suppressing the hardening effects. With increasing indentation depth, the load-depth curve exhibits multiple load drops accompanied by nonlinear increases in Shockley partial dislocation density. It is thus evident that the stability of resultant dislocation networks dictates the macroscopic mechanical response and extent of work hardening observed under different loading conditions. Elucidating these rate-dependent sessile lock formation mechanisms and gaining a deep understanding of defect evolution mechanisms not only contribute to the advancement of multiscale crystal plasticity modeling, but also provide significant guidance for optimizing micro-nano processing parameters, predicting the failure behavior of nickel-based superalloys in critical engineering components, and enhancing their surface integrity.
2026 Vol. 47 (1): 52-65 [
Abstract
] (
6
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
66
Study on the mechanical behavior of quasicrystal multilayered beams with elastic medium
As an advanced material, quasicrystal (QC) exhibits distinctive physical characteristics including high hardness, a low friction coefficient, and exceptional wear resistance that make them promising for multifunctional structural applications. Despite substantial progress in understanding the intrinsic properties of QC materials, their mechanical behavior when incorporated into complex structural systems remains insufficiently understood. In particular, the response mechanisms of QC structures under multi-field coupling conditions have not yet been fully clarified. Among these challenges, the mechanical performance of QC laminated beams interacting with elastic media remains an underexplored problem. This paper investigates the buckling, vibration, and bending of simply-supported one-dimensional (1D) hexagonal QC layered beams interacting with an elastic medium. The model is formulated using the pseudo-Stroh formulation combined with the transfer matrix method. The general solution is derived for the critical buckling load, natural frequencies, bending deflection, and stresses under two typical elastic medium configurations: beams embedded in the medium and beams resting on it. The accuracy of the model is validated by comparing results with existing studies. Numerical examples systematically examine the effects of the slenderness ratio, stacking sequence, and elastic-medium parameters on the mechanical responses. The results show that simply-supported 1D hexagonal QC layered beams embedded in the elastic medium exhibit higher natural frequencies and critical buckling loads than those resting on it. Stacking sequences with higher elastic constants in the outer layers significantly improve structural performance. Both Winkler stiffness KW and shear modulus KG enhance the frequency and buckling capacity, with KW having a stronger influence due to its direct relation to displacement. Structural symmetry determines the mode shapes: symmetric distributions occur for beams embedded in or without elastic media, while beams on the medium show asymmetry. This study provides exact analytical solutions and design insights for QC layered beams in elastic media, offering a theoretical foundation for further numerical and experimental research in aerospace, mechanical, and composite engineering.
2026 Vol. 47 (1): 66-82 [
Abstract
] (
5
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
83
Study on Modeling and Optimization Method for High-Temperature Resistance and Miniaturization of Electromagnetic Ultrasonic Transducers Under Variable Loads
Electromagnetic acoustic transducers (EMATs) face permanent magnet demagnetization issues in high-temperature applications. This makes online inspection under extreme conditions very difficult. Modern aerospace systems demand compact, high-performance sensors that can work in harsh environments, such as high temperature, high speed, and confined spaces. Current solutions often rely on external cooling, high-temperature materials, or thermal barriers. However, few studies explore structural optimization under combined thermal and mechanical loads. To achieve high-temperature miniaturization, this paper presents a new probe design for EMATs. A thermodynamic finite element model of the probe was constructed. The key idea is to treat the outer shell as both a design variable and the main carrier of thermal load. Optimized Latin hypercube sampling is used to generate an efficient set of initial design points across the parameter space. A sensitivity study is then carried out to evaluate the effects of each geometric parameter. It is found that the shell thickness is identified as the dominant factor governing both thermal and mechanical responses. The results reveal a counterintuitive finding, reducing shell thickness—typically expected to increase stress or temperature—actually lowers both peak temperature and stress in the system. This happens because the thinner shells improve heat dissipation and reduce thermal mass. More importantly, thermal and mechanical responses are not in conflict, and instead, they are simultaneously improved through the same design variable: shell thickness. This breaks from traditional design, where thermal and structural goals often compete. The method enables compact, high-temperature EMATs without additional cooling or exotic materials. It is demonstrated that the integrated thermomechanical optimization can align multiple performance goals into a unified design strategy. The approach holds great promise for other high-temperature sensing or actuation systems in aerospace engines, nuclear reactors, and advanced manufacturing processes, where size, weight, reliability, and thermal resilience are critical.
2026 Vol. 47 (1): 83-95 [
Abstract
] (
5
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
96
Analytical solution for displacement and stress distributions of double-layer interference-fit functionally graded cylinder/sphere structures under coupled effects of magnetic field and internal pressure
With the advancement of composite manufacturing techniques, functionally graded (FG) materials have emerged as an effective solution to the interface issues inherent in traditional composite materials due to their spatially continuous gradient properties. The application of the interference fit technique in FG cylinder/sphere structures further enhances the load-bearing capacity and fatigue life. Therefore, investigating the mechanical behavior of such structures under multi-field coupling is essential for ensuring structural reliability. However, the exact analytical models are still lacking for the mechanical response of double-layer interference-fit FG structures subjected to combined internal pressure and magnetic field, particularly when material properties follow a power-law gradient. This gap continues to constrain their optimal design and safety assessment. This study aims to develop an analytical model for predicting the mechanical response of double-layer interference-fit FG cylinder/sphere structures subjected to coupled internal pressure and magnetic field. Under the assumption of axial/spherical symmetry, considering the power-law variation of elastic modulus and Lorentz force along the thickness direction, this study first derives the governing equations and fundamental solutions for the displacement and stresses based on the fundamental equations of elasticity theory and boundary conditions. Subsequently, by investigating the relationship between the interference value and the displacement at the contact interface, an expression for the contact pressure as a function of the interference value is obtained. Consequently, a comprehensive analytical model is developed for the displacement and stresses in a double-layer interference-fit FG structures under the coupled effects of internal pressure and magnetic field. The model can accurately describe the mechanical response of the interference fit under multi-physics coupling, and reveal the effects of the interference value, material gradient parameter, geometric dimension and external magnetic field on the displacement and stress distributions of the structures. It provides a theoretical and computational foundation for the mechanical design of the FG interference fit. The results indicate that by adjusting these parameters, the interfacial stress distribution can be optimized and stress concentration mitigated, thereby enhancing the load-bearing capacity and reliability. The analytical model in this work provides a theoretical and numerical basis for the design and assessment of interference-fit FG structures under multi-physical field coupling.
2026 Vol. 47 (1): 96-108 [
Abstract
] (
8
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
109
Mechanistic Study on the Influence of Non-Tip Crack Geometry on Mixed-Mode I–II Fracture Behavior
Crack initiation and propagation in structural components under complex mixed-mode loading conditions are highly sensitive to geometric irregularities. However, existing fracture studies predominantly focus on sharp-tip cracks, while the influence of non-tip geometric features on fracture response is often overlooked. Addressing this limitation is therefore essential for accurate damage tolerance evaluation and structural integrity assessment. This study investigates a lip-shaped crack configuration that incorporates both tip singularity and an outward convex non-tip geometry. Within a linear elastic fracture mechanics framework supplemented by conformal mapping, an I–II mixed-mode crack model is established, and theoretical predictions of the crack-tip energy release rate and fracture initiation angle are obtained based on the maximum energy release rate criterion. By varying the crack inclination angle to control the loading mode and characterizing the non-tip geometry through the width-to-length ratio, the effects of geometric parameters are systematically analyzed. Furthermore, crack-growth simulations, combined with elastoplastic finite element analyses of the evolving plastic zone and stress-field redistribution, are conducted to elucidate the mechanisms by which non-tip geometry influences crack failure behavior. Results indicate that the outward convex non-tip geometry reduces tip stress concentration, leading to a decrease in energy release rate and a deflection of the crack initiation angle. Changes in loading mode cause the stress concentration to shift from the crack tip to the non-tip region, giving rise to two distinct failure patterns—tip-dominated and non-tip-dominated—and a critical inclination angle governed solely by the width-to-length ratio is identified. This study highlights the essential role of non-tip geometry in mixed-mode fracture and provides theoretical guidance for structural failure prediction and damage-tolerant design. The findings offer practical value for safety-critical structures subjected to combined loading, particularly in aerospace, transportation, and advanced manufacturing applications.
2026 Vol. 47 (1): 109-124 [
Abstract
] (
9
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
125
Research on Force Transmission Characteristics of Cable Pulley System under Impact Loads
This study investigates the dynamic force transmission in cable-pulley systems under impact loading. A dynamic model is developed that incorporates cable axial vibration, nonlinear friction, pulley damping, and energy distribution. Using an integrated approach of theoretical analysis, finite element simulation, and experimental validation, the research elucidates the effects of pulley wrap angle and damping on tension transmission during impact. The results indicate that pulley damping is a key parameter governing the system's impact tension response—increased damping significantly reduces transmission efficiency. Meanwhile, a larger wrap angle enhances energy dissipation by extending the contact arc, leading to a slight decrease in transmission efficiency. The proposed modified friction model offers improved accuracy in predicting tension response under impact conditions, providing a theoretical basis for the safety design of engineering equipment equipped with cable-pulley mechanisms.
2026 Vol. 47 (1): 125-140 [
Abstract
] (
2
)
HTML
(1 KB)
PDF
(0 KB) (
1
)
News
Download
Download
Download
Links
Links
Copyright © Editorial Board of
Supported by:
Beijing Magtech
