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Ballast failures restored and detecting methodology for lateral resistance of ballast bed during dynamic stabilization

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engineering Failure Analysis 2025年 176卷

作者： Zhang, Zhihai Xiao, Hong Ma, Chaozhi Tong, Fengzhuang Ding, Dong Li, Jianguo School of Highway Chang'an University Xi'an710064 China School of Civil Engineering Beijing Jiaotong University Beijing100044 China School of Mechanics and Civil Engineering China University of Mining and Technology Xuzhou221116 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China

Stabilization can effectively restore the bearing capacity and lateral deformation resistance of the failed ballast bed. However, unreasonable operating modes can also affect the lateral stability of the ballast bed and the status of the line. To improve the quality of stabilizing operations and save the construction cost of new railways, the paper established a stabilizing machine-ballasted track model based on the DEM-MFBD algorithm, and carefully analyzed the contact separation, reorganization and migration characteristics of ballast particles during the stabilizing. The microscopic movement mechanism of ballast particles is revealed. Based on the mapping relationship between the PSD of the lateral vibration characteristics of the stabilizing machine and the ballast bed resistance, a new method for detecting the lateral resistance of the ballast is proposed. This detection method realizes the rapid acquisition and data transmission of the ballast bed status, and uses a stabilizing machine as the force source, without the need to add a reaction force device. Therefore, it is more efficient than traditional detection methods. Finally, a multi-point track panel lateral resistance index is proposed, the stabilizing operation effect is evaluated, and the optimal operation mode is given. The results show that the effects of the front and rear stabilizers on the ballast bed should be considered during on-site stabilization, and the operating frequency of the first stabilizer should be appropriately reduced to increase the number of contacts between ballast particles and improve the stability of the ballast bed after the stabilization. The new method for detecting the lateral resistance of the ballast bed can be used to easily obtain the mechanical state of the ballast bed before and after stabilizing operation under different line conditions. More stabilization times does not necessarily mean better results. This study provides effective guidance for improving the perfo

关键词： Subways

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Study on dynamic slaking response characteristics and calculation model of fouled ballast materials in heavy-haul railways

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Construction and Building Materials 2025年 481卷

作者： Yang, Zhihao Liu, Hengwen Deng, Xi Feng, Huaiping Chang, Jianmei Ma, Deliang Feng, Xiaoqing State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Traffic and Transportation Shijiazhuang Tiedao University Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

Investigating the dynamic slaking characteristics of fouled ballast is critical for elucidating the mud pumping mechanisms in heavy-haul railway ballasted track beds. In this study, in-situ fouled ballast materials from typical mud pumping sections were collected, and a series of dynamic slaking triaxial tests were conducted. The coupled effects of loading frequency, dynamic stress amplitude, and confining pressure on deformation behavior, water infiltration patterns, and moisture migration characteristics under dynamic slaking conditions were systematically examined. Moreover, the evolutionary mechanisms of softening indices in plastically creeping specimens were quantitatively analyzed, yielding computational models for both softening indices and accumulative plastic strain. Furthermore, based on the improved Iwan series model, a calculation model of the dynamic stress-strain relationship considering the load amplitude and frequency under dynamic slaking conditions was established. The dynamic slaking deformation mechanism of fouled ballast was discussed from three aspects: the hysteresis effect of dynamic slaking deformation, the critical frequency regulation mechanism, and the hydromechanical coupling and feedback laws. Based on the findings, a "frequency-amplitude" collaborative control strategy is proposed for mitigating mud pumping diseases in ballasted track beds. © 2025 Elsevier Ltd

关键词： Ballast (railroad track)

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A sequoia-ecology-based metaheuristic optimisation algorithm for multi-constraint engineering design and UAV path planning

Results in Engineering

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Results in engineering 2025年 26卷

作者： Fan, Shijie Wang, Ruichen Su, Kang Song, Yang Wang, Rui State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China School of Electrical Engineering Southwest Jiaotong University Chengdu611756 China

Current metaheuristic algorithms are typically confined to inspiration from singular perspectives, isolated biological behaviours, or individual phenomena, resulting in inherent limitations that have motivated this study. Diverging from conventional approaches, this paper explores complex biological systems from an ecosystem perspective and conducts comprehensive system modelling, analysis, and algorithmic innovation. Specifically, a novel metaheuristic optimization algorithm inspired by the self-regulating and restorative phenomena observed in sequoia forest ecosystems called the Sequoia Optimization Algorithm (SequoiaOA) is proposed. The sequoia ecosystem exhibits distinctive characteristics including collective growth, resource sharing and networking, adaptability and resilience, reproduction and diversity, and elite retention. Building upon these phenomena, this work presents the first formulation of SequoiaOA, developing its mathematical model and engineering applications through algorithmic modelling and validation from the perspective of ecosystem complexity, self-regulation, and resilience in macro systems. Comparative experiments employing CEC2017 and CEC2022 benchmark functions demonstrate the algorithm's effectiveness through benchmarking against six established metaheuristic algorithms. SequoiaOA achieved superior performance in over 40 % of test functions, outperforming competitors in terms of mean values and variance of objective function measures. Furthermore, its efficacy in addressing real-world multi-constrained engineering challenges was validated through eight engineering design problems. Additional modelling and application experiments in UAV path planning underscore its practical applicability to trajectory optimization tasks. The in-depth discussions reveal that SequoiaOA possesses significant potential for future enhancements and demonstrates broad suitability for diverse optimization problems. The implementation code is available in the Appe

关键词： Biotic

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Research on the Control Technology of High Water Temperature Tunnel Grouting Water Plugging and Heat Insulation 11th

Research on the Control Technology of High Water Temperature...

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11th International Conference on Civil engineering, ICCE 2024

作者： Yang, Tengjie Tian, Baolei Xue, Yongqing Gao, Xinqiang State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang 050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang 050043 China China Railway 18th Bureau Group Corporation Limited Tianjin 300222 China

ISBN: (纸本)9783031879586

The surrounding rock experiences the combined impacts of elevated ground stress, high water pressure, and hot groundwater during the deep-buried tunnels with high water temperatures. The stress in the surrounding rock and groundwater flow significantly affects the temperature variations in the tunnel's construction environment. Therefore, studying heat insulation and cooling measures while constructing high-water temperature tunnels is significant. This study uses a numerical simulation method to analyze water plugging and cooling feasibility in high-water temperature tunnels through grouting measures under thermal-fluid-solid coupling conditions. The variation characteristics and laws of the tunnel's stress field, seepage field, and temperature field surrounding rock under different grouting parameters are discussed. The results show that underground hot water is significantly lost when tunnels are excavated without grouting, and the tunnel wall's cooling effect is inferior. After constructing a 5 m grouting ring, excavating the tunnel significantly affects the seepage and temperature fields within the grouting ring. The seepage flow of underground hot water in the tunnel is reduced to about 1/2942 of its original value before grouting, and the temperature of the tunnel wall is significantly reduced. Through orthogonal testing, the order of influence of different grouting parameters on the average temperature of the tunnel wall is determined as follows: grouting permeability k > grouting thickness d > solid thermal conductivity of the grouting ring λ > thermal expansion coefficient of the grouting ring β. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Grouting Prevention and Control High Water Temperature Tunnel Numerical Simulation Orthogonal Test Thermal-Fluid-Solid Coupling

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Research on dynamic characteristics of electromagnetic SD oscillator system under state feedback control

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International Journal of Non-Linear Mechanics 2025年 176卷

作者： Wang, Meiqi Zu, Qian Wang, Ruichen Qin, Chengwei Liu, Pengfei School of Mechanical Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Hebei Key Laboratory of Mechanical Power and Transmission Control Shijiazhuang Tiedao University Shijiazhuang050043 China CRRC Tangshan Co. Ltd Tangshan064000 China

To enhance the robustness of the smooth and discontinuous (SD) oscillator system, an electromagnet incorporating displacement-velocity state feedback control is integrated above the oscillator. The electromagnetic interaction between the electromagnet and the oscillator facilitates accelerated system stabilization. This study investigates a novel electromagnetic SD oscillator. Initially, the steady-state amplitude-frequency and phase-frequency response characteristics are derived using the averaging method, with an analysis of how each state feedback parameter influences the amplitude-frequency curve. Utilizing Lyapunov stability theory and the Routh criterion, the stability conditions for the system's periodic solutions are established. Subsequently, the Melnikov theorem is employed to determine the necessary conditions for the onset of chaos within the system. Dynamic bifurcation analysis, maximum Lyapunov exponent (LLE) curves, and system behaviors under various parameters are examined to assess the impact of state feedback parameters on the chaotic boundary curve. On this basis, the global bifurcation characteristics of different parameters of the system are studied by using the cell mapping method, and the influence of each parameter on the number of attractors and the domain of attraction is analyzed. Finally, the displacement transmissibility is used to evaluate the vibration isolation effect of the system. The findings indicate that the electromagnetic SD oscillator exhibits superior vibration reduction capabilities, effectively mitigating chaos and bifurcation phenomena. Optimal selection of state feedback parameters enables rapid system stabilization under external excitation conditions. © 2025 Elsevier Ltd

关键词： state feedback

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Reinforcing shell elements for fiber-reinforced composites undergoing large deformations and general motion

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Composite structures 2025年 366卷

作者： Li, Yanhu Lu, Yongjie Song, Jibo Zhang, Linao State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University No. 17 North 2nd Ring East Road Shijiazhuang Hebei050043 China School of Mechanical Engineering Shijiazhuang Tiedao University No. 17 North 2nd Ring East Road Shijiazhuang Hebei050043 China Department of Mechanical and Electrical Engineering Shijiazhuang College of Applied Technology No. 226 Tianning Road Shijiazhuang Hebei050043 China

Fiber-reinforced composites offer excellent mechanical properties and lightweight advantages in multibody systems. However, their significant anisotropy and geometrical and material nonlinearities present challenges for accurate modeling and simulation. In this paper, two new types of reinforcing shell elements are developed within the Absolute Nodal Coordinate Formulation framework. The first type assumes that each fiber behaves as an Euler beam with only tensile and bending stiffness, making it suitable for simulating reinforcing fibers with arbitrary orientations and nonuniform materials and cross-section areas. The second type employs elastic force formulation based on Kirchhoff–Love theory or continuum mechanics. It is suitable for simulating reinforcing fibers that appear in a layered form with unique orientation, material, and cross-section area. The fibers and matrix are described independently in these new reinforcing elements, coupled through consistent deformation compatibility conditions. This approach allows different material models and element formulations for the fibers and matrix to be used. Furthermore, multiple fibers (or layers) can be embedded within a single reinforcing shell element, providing more accurate representations of the actual physical structure. The effectiveness of the developed reinforcing elements is validated through several benchmark problems. Numerical results demonstrate that both types of reinforcing shell elements are locking-free and can automatically capture the reinforcing effects of the fibers and the coupled deformation modes. This investigation enriches the element library of the Absolute Nodal Coordinate Formulation and provides an effective tool for the accurate simulation and optimal design of fiber-reinforced composites in multibody systems. © 2025

关键词： Shells (structures)

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Fractional-order visco-plastic constitutive model for uniaxial ratcheting behaviors

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Applied Mathematics and Mechanics(English Edition) 2019年第1期40卷 49-62页

作者： Wenjie ZHAO Shaopu YANG Guilin WEN Xuehong REN State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University State Key Laboratory of Mechanical Behavior in Traffic Engineering Structure and System Safety Shijiazhuang Tiedao University

This paper proposes a novel unified visco-plastic constitutive model for uniaxial ratcheting behaviors. The cyclic deformation of the material presents remarkable time-dependence and history memory phenomena. The fractional(fractional-order)derivative is an efficient tool for modeling these phenomena. Therefore, we develop a cyclic fractional-order unified visco-plastic(FVP) constitutive model. Specifically, within the framework of the cyclic elasto-plastic theory, the fractional derivative is used to describe the accumulated plastic strain rate and nonlinear kinematic hardening rule based on the Ohno-Abdel-Karim model. Moreover, a new radial return method for the back stress is developed to describe the unclosed hysteresis loops of the stress-strain *** capacity of the FVP model used to predict the cyclic deformation of the SS304 stainless steel is verified through a comparison with the corresponding experimental data found in the literature(KANG, G. Z., KAN, Q. H., ZHANG, J., and SUN, Y. F. Timedependent ratcheting experiments of SS304 stainless steel. International Journal of Plasticity, 22(5), 858–894(2006)). The FVP model is shown to be successful in predicting the rate-dependent ratcheting behaviors of the SS304 stainless steel.

关键词： cyclic visco-plastic constitutive fractional derivative fractional-order uni-fied visco-plastic(FVP)model rate-dependent ratcheting

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Crack propagation behavior in metal matrix composites: A coupled nonlocal crystal plasticity and phase field modelling

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Journal of the Mechanics and Physics of Solids 2025年 200卷

作者： Xiong, Yukai Zhao, Jianfeng Zeng, Qinglei Yuan, Fuping Zhang, Xu Sichuan Province Key Laboratory of Advanced Structural Materials Mechanical Behavior and Service Safety School of Mechanics and Aerospace Engineering Southwest Jiaotong University Chengdu611756 China School of Materials Science and Engineering Southwest Jiaotong University Chengdu610031 China Institute of Advanced Structure Technology Beijing Institute of Technology Beijing 100081 China State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China

The aluminum matrix composite is known for its lightweight and high strength, while its application is limited in various fields due to its low fracture strain. Configuring reinforcements in metal matrix composites (MMCs) is effective in improving the strength-ductility synergy of metallic materials;however, the underlying mechanisms have yet to be elucidated, and an optimizing strategy is to be explored. This study developed a coupled crystal plasticity (CP) and phase field (PF) model to investigate the toughening mechanisms of MMCs. The CP module incorporates a dislocation flux-based nonlocal model, while the PF module considers the influence of geometrically necessary dislocations (GNDs) on crack initiation and propagation. This coupled model effectively captures the initiation of cracks near the interface due to the accumulation of GNDs at the grain boundary and particle surface. systematic simulations comprehensively reveal the effects of particle distribution and particle strength on the fracture strain. The findings suggest that arranging particles near grain boundaries improves ductility when particle damage is ignored. However, experimental observations reveal that particles undergo damage during deformation. Only when particle damage is incorporated, does the model accurately reflect the enhanced ductility in scenarios where particles are distributed within the grain interior aligning better with experimental findings. This research enhances our understanding of the damage mechanisms in MMCs and provides valuable insights into their microstructural design. © 2025 Elsevier Ltd

关键词： Metallic matrix composites

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Design and vibration reduction performance analysis of a 6-DOF nonlinear vibration isolation platform by employing bio-inspired multi-joint X-structure

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Nonlinear Dynamics 2025年

作者： Jiang, Guoqing Zang, Haoxiang Xiong, Yuanhao Shen, Yongjun Guo, Zhenkun Yang, Yang Li, Meng School of Mechanical Engineering Zhejiang Sci-Tech University Hangzhou 310018 China School of Civil Engineering & Transportation Beihua University Jilin 132013 China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang 050043 China Beijing Engineering Research Center of Monitoring for Construction Safety Beijing University of Civil Engineering and Architecture Beijing 100044 China School of Mechanics and Aerospace Engineering Southwest Jiaotong University Chengdu 610031 China

A novel six-degree-of-freedom (6-DOF) passive vibration isolation platform is studied, which consists of six nonlinear bionic multi-joint isolation structures, top and base platforms. It achieves excellent and adjustable vibration isolation performance in all six directions. By using the multi-rigid system analysis method, the static equilibrium equation and dynamic equation of the 6-DOF isolation platform are established. Vibration isolation performance in six directions (three translational and three rotational) is analyzed, with transmissibility as the indicator. The results show that: (a) By appropriately adjusting structural parameters based on their impact on the platform’s nonlinear stiffness characteristics, the vibration isolation performance in one direction can be optimized (with the minimum isolation frequency reaching as low as 1.1 Hz) without compromising the platform’s loading capacity;(b) By symmetrically arranging the multi-joint structures between layers, the novel vibration isolation platform can demonstrate superior high static and low dynamic stiffness (HSLDS) property and thus excellent vibration isolation performance;(c) The designed isolation platform exhibits low dynamic stiffness even when positioned far from the vibration equilibrium point, enabling low-frequency isolation performance under large displacement vibrations;(d) The platform exhibits directional differences in vibration isolation performance, with better isolation observed in the P_x and P_y directions compared to P_z, and in the P_α and P_β directions compared to P_γ. © The Author(s), under exclusive licence to Springer Nature B.V. 2025.

关键词： Bio-inspired structure Nonlinear vibration isolation Six directions vibration isolation Stewart platform

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The investigation of α/β interface structure in Ti-5Al-6Nb(V/Cr) model titanium alloys

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Materials Characterization 2025年 225卷

作者： Zhu, Wenguang Yang, Ruifeng Yang, Jiakun Xu, Xingge He, Ye Zhang, Jin-Yu Fu, Anqing Zhang, Conghui Zhang, Hualei Zhang, Jinyu School of Metallurgical Engineering Xi'an University of Architecture and Technology Shaanxi Xi'an 710055 China State Key Laboratory for Mechanical Behavior of Materials Xi’ an Jiaotong University Shaanxi Xi’ an 710049 China Department of Mechanical Science and Bioengineering Osaka University Osaka 560-8531 Japan State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials Shaanxi Xi'an China

The structure of the α/β phase interface, which includes component such as interface misfit, dislocations, and step structures, critically influences the mechanical strength and stress distribution in titanium alloys. Pursuing an in-depth understanding of these characteristics, Ti-Al-Nb (V, Cr) ternary alloy system were ingeniously developed utilizing the Exact Muffin-Tin Orbitals (EMTO)-Coherent Potential Approximation (CPA) method to vary interface misfits. The study revealed that Ti-5(at.%)Al-6(at.%)Cr exhibited the highest misfit, followed by Ti-5Al-6 V and Ti-5Al-6Nb demonstrating the lowest. Misfits were experimentally characterized at various aging temperatures through selected area electron diffraction (SAED), aligning closely with theoretical predictions. High-resolution transmission electron microscopy (HRTEM) facilitated a detailed examination of Ti-5Al-6 V and Ti-5Al-6Nb, uncovering a shared broad interface step structure: the broad face of the α precipitate consists of areas of coherent terrace planes on 11¯00_α‖112_βand ledge planes on 01¯10_α‖110_β. Besides, the height of the ledges characterized is twice the 112_βinterplanar spacing. Upon comparison with the initial phase transition, the equilibrium state α/β interface misfit was observed to increase, with a reduction in coherent regions. Notably, the Ti-5Al-6Nb alloy, with its lower misfit, presents broader terrace widths and reduced step density compared to Ti-5Al-6 V, suggesting an intrinsic link to the distinct transformation strains induced by V and Nb component. © 2025 Elsevier Inc.

关键词： Interface structure Lattice misfit Microstructure Precipitate Titanium alloys

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