最新刊期
卷 47 ， 期 11 ， 2025
- 摘要：Taking the mass-spring system as the research object, the mathematical modeling methods for linear and nonlinear vibration models were systematically explored. Emphasis was placed on analyzing the stability of equilibrium points, the dynamic behaviors of micro-vibrations and large-amplitude vibrations,and an unconventional phenomenon was revealed. A nonlinear vibration mathematical model of the mass-spring system was established using Lagrange’s equations. The number and positions of the system’s equilibrium points were solved, and micro-vibrations were treated in three categories. For the conventional case (with only one stable equilibrium point and a quadratic term in potential energy), a linear vibration equation was obtained via an approximate method. For the case with multiple stable equilibrium points, multiple linear vibration equations were derived using the approximate method near each equilibrium point. For the stable equilibrium position with essential nonlinearity (without a quadratic term in potential energy), only the quartic term of potential energy was retained, leading to the acquisition of an approximate micro-vibration equation with pure cubic displacement. The analytical solution of the approximate micro-vibration equation with pure cubic displacement was solved using the harmonic-energy balance method.For micro-vibrations, the analytical solution of the approximate vibration equation was compared with the numerical solution of the exact nonlinear vibration equation, and the solutions exhibited high similarity. For large-amplitude vibrations, numerical simulation was adopted; comparative analyses were conducted under different parameters and initial conditions by integrating time-history curves, phase portraits,and FFT analysis, which verified the rationality of the model and the effectiveness of the method.Meanwhile, an unconventional phenomenon was discovered: small-displacement initial conditions induced large-amplitude vibrations, whereas large-displacement initial conditions induced small-amplitude vibrations.A reasonable explanation for this unconventional phenomenon was also provided.关键词：Micro vibration;Unconventional phenomenon;Multiple equilibrium point;Intrinsic nonlinearity;Harmonic energy balance method80|20|0更新时间：2025-11-26
- 摘要：Field modulated magnetic gears can effectively avoid vibration, noise, lubrication and other problems. In order to improve the transmission stability, a new type of field modulated magnetic gear using eccentric poles was proposed. Firstly, the magnetic field modulation effect before and after adding the magnetic field modulating pole piece was analyzed by analytical method, and the expression of the air-gap magnetic density was obtained after the modulation of the permanent magnetic field.Secondly， the main structural parameters of the eccentric pole were defined, and the functional expression of the magnetization thickness of the eccentric pole was deduced. Then, the effect of the magnetic field on the air-gap magnetic gear before and after adopting the eccentric magnetic pole was analyzed by using the simulation of the finite element software, and applied Fourier decomposition to the waveform of the air-gap magnetic density for calculating total the harmonic distortion. Finally, the parametric analysis of the relation between the pole-arc coefficient of the modulating pole piece, the eccentricity of the permanent magnet, the pole-arc coefficient of the permanent magnet and the air gap magnetic density and the maximum static torque was carried out, and a prototype of the magnetic gear with an eccentricity of 0 was fabricated to validate the theoretical and simulative analyses. The results show that the structure of the eccentric poles can improve the waveform of air-gap magnetic density effectively and improve the stability of the transmission.关键词：Eccentric pole;Magnetic gear;Air gap magnetic density;Total harmonic distortion20|6|0更新时间：2025-11-26
- 摘要：To solve the stress concentration problem caused by tooth interference and insufficient tooth surface contact during the operation of harmonic reducers, an axial modification method based on the finite element method (FEM) was proposed. Firstly, the profiles of the flexspline and circular spline were designed based on the requirement of tooth contact analysis (TCA), laying a foundation for the accurate simulation of the working state of the harmonic reducer. Subsequently, the flexspline model was reconstructed based on the FEM for TCA. On the premise of maintaining the integrity of the original flexspline profile, axial modification was conducted. Finally, the modification effect was verified through finite element simulation. The results show that after modification, the maximum equivalent stress and meshing pressure on the flexspline tooth surface are significantly reduced, and the tooth surface contact area is obviously expanded. This method effectively solves the problems of tooth interference and stress concentration, significantly improves transmission smoothness, and provides technical reference for the optimization of gear meshing performance of harmonic reducers.关键词：Harmonic reducer;Flexspline profile;Axial modification;Finite element method;Meshing performance17|9|0更新时间：2025-11-26
- 摘要：The zero Poisson ratio honeycomb structure exhibits nonlinear phenomena in the deformation design process, which makes it difficult to predict and analyze its equivalent elastic performance. A zero Poisson ratio honeycomb structure equivalent calculation model based on the finite element (FE) method and the representative volume element (RVE) method was proposed. The RVE model was established using periodic boundary conditions with displacement constraints, and the applicability of shell elements and solid elements was compared. The stiffness updating method was used for nonlinear simulation calculation of the honeycomb structure equivalent model, and the accuracy of the calculation results was verified by comparison with existing theories, numerical methods and experiments. The influence of unit cell geometry parameters on the geometric nonlinear equivalent elastic modulus of accordion honeycomb structure was analyzed, providing an efficient calculation method for the nonlinear equivalent analysis of the zero Poisson ratio honeycomb structure.关键词：Zero Poisson ratio;Nonlinear;Representative volume element;Equivalent elastic modulus17|6|0更新时间：2025-11-26
- 摘要：Geometric parameter errors exist in the structural design, manufacturing, and motion processes of multi-crane suspension systems, which easily lead to insufficient operational accuracy of the system. Taking the suspension system as the research object, a kinematic model of the system was established using the closed-loop vector method. Considering the original errors from kinematic parameters, a pose error model of the suspended object was developed based on the total differential method of matrices. Through sensitivity analysis methods in statistics, the influence of different error sources on the accuracy of the suspended object was investigated. Combined with practical examples, the error impact patterns of the system were simulated, and a method for evaluating the error response of the suspended object was proposed. The obtained results not only provide a basis for precision design, but also offer certain guidance for practical engineering applications.关键词：Multi-crane suspension system;Kinematic model;Error model;Sensitivity analysis;Accuracy6|6|0更新时间：2025-11-26
- 摘要：Focusing on the performance of single-orifice aerostatic bearings, the effect of design parameters on load capacity and stiffness was investigated, aiming to optimize the structural design and performance of aerostatic bearings. A parametric model of the single-orifice aerostatic bearing was developed using the finite element method. The influence of factors such as air cavity design, orifice diameter, supply air pressure, air film thickness, orifice depth, air cavity thickness, and air cavity diameter on bearing performance was analyzed. Simulation and test were combined to validate the influence of design parameters on bearing performance. The results indicate that orifice diameter, air film thickness, supply air pressure, and air cavity diameter significantly affect the bearing's load capacity, while orifice depth and air cavity thickness have a smaller impact. Parameters such as orifice diameter, supply air pressure, air cavity diameter, and air cavity thickness positively correlate with load capacity, whereas air film thickness and orifice depth negatively correlate. Additionally, aerostatic bearing with air cavity structures exhibits superior load capacity and stiffness compared to that without air cavities. The consistency between simulation results and test data confirms the reliability and accuracy of the proposed simulation model.关键词：Small orifice;Air floatation mat;Finite element method;Load-carrying capacity;Stiffness183|323|0更新时间：2025-11-26
- 摘要：The acceleration of the reciprocating parts of the compressor with the crosshead settlement fluctuates violently, and the comprehensive piston force becomes larger, which leads to the increase of the vibration amplitude of the crankshaft and the instability of the vibration. Therefore, this paper firstly studied the kinematic law of the crosshead settlement on the crank-connecting rod structure, and established the differential equation of the torsional vibration of the crankshaft. Subsequently, the vibration response characteristics of the crankshaft were solved by the mean filtering-Runge-Kutta method. Finally, the influence of the crosshead settlement, motor speed and reciprocating mass of the piston assembly on the crankshaft vibration amplitude, phase trajectory and amplitude-frequency diagram was discussed. The results show that with the increase of the crosshead settlement, the “serrated” fluctuation of the crankshaft phase space trajectory line is intensified, and the torsional angular velocity shows an upward trend. When d=0.25 mm, the torsional angular velocity amplitude increases by 23.6% compared with that without the settlement, and the crankshaft vibration state changes from frequency doubling period to chaos. As the motor speed decreases, the torsional angle and vibration state fluctuation of the crankshaft are controlled. As the reciprocating mass of the piston assembly decreases, the peak frequency response decreases, which helps to control the crankshaft torsion angle. The research can provide a theoretical guidance for predicting the vibration state of the crankshaft and the torsional vibration control of the crankshaft under the condition of the crosshead settlement, and ensure the stable operation of the crankshaft.关键词：Crosshead settlement;Torsional vibration;Mean filtering-Runge-Kutta method;Phase trajectory;Vibration state9|6|0更新时间：2025-11-26
- 摘要：TPMS porous structures possess excellent mechanical properties and high specific surface area, making them commonly applied in structural design. However, the hybridization between different structures and the effects of hybridization parameters on model performance remain insufficiently studied. Accordingly, the in-situ hybridization of Diamond and Schwarz P models within TPMS porous structures were conducted, and the mean deviation angle was analyzed. Additionally, a novel Diamond/Schwarz P model was fabricated using FDM, and the pore characteristics, compressive strength, and deformation behavior of the models under various hybridization parameters were explored. The results indicate that the bearing capacity of the Diamond/Schwarz P models exhibit nonlinear variation under different hybridization proportions. Specifically, the original Schwarz P model exhibits a compressive strength of 1.72 MPa and a mean deviation angle of 48.48°. Among models primarily based on Schwarz P, the model with a ratio of 3∶7 exhibits the best bearing capacity, with a compressive strength of 2.17 MPa and a mean deviation angle of 49.36°. The original Diamond model has a compressive strength of 5.57 MPa and a mean deviation angle of 52.06°. Among models primarily based on Diamond, the model with a ratio of 8∶2 exhibits the best bearing capacity, with a compressive strength of 6.05 MPa and a mean deviation angle of 52.09°. However, bearing capacity of models decrease at the ratio of 6∶4 and 7∶3, accompanied by a reduction of the mean deviation angle. On this basis, the reasons for differences in bearing capacity among different models were explained using the mean deviation angle, which successfully predicted that the model exhibits the best capacity at the ratio of 8∶2, thus demonstrating the conclusion that parameter design can accurately regulate the bearing capacity of the model.关键词：Triply periodic minimal surface;Bearing capacity;In-situ hybridization;Parameter design9|4|0更新时间：2025-11-26
- 摘要：Currently, the development of software for polycrystalline diamond compact (PDC) bits is focused primarily on pilot bits, while no research on software for pilot-reamer bits has been reported. Moreover, the analysis of PDC bit rock-breaking performance is often conducted based on finite element simulation methods, which have limitations such as low efficiency, high time cost，and poor flexibility—greatly restricting the progress of bit design and development.To address this issue, a rock-breaking performance analysis platform for pilot-reamer bits based on Matlab/Graphical User Interface (GUI) was designed, aiming to provide an efficient tool for the evaluation and optimization of pilot-reamer bit rock-breaking performance. This platform utilized the numerical calculation capability of Matlab software and the image processing function of GUI. The zero-point traversal method was adopted, and combined with the cutting force model of cutting teeth, the platform could calculate the cutting parameters of cutting teeth and the force state of pilot-reamer bits. It could also quickly select the optimal drilling-reaming combination type based on environmental formation parameters, analyze the hydraulic characteristics of pilot-reamer bits, and thereby realize the rock-breaking performance analysis function. The results show that the software has strong adaptability and high efficiency. It can conduct batch analysis of the rock-breaking performance of pilot-reamer bits with different tooth arrangement structures in a short time, which provides important guiding significance for improving the design and development of pilot-reamer bits.关键词：Matlab/GUI;Pilot hole-expanding drill bit;Rock-breaking performance;Tooth layout parameters;Zero-point traversal method;Hydraulic analysis5|5|0更新时间：2025-11-26
- 摘要：Negative stiffness multistable structures are widely utilized across various fields due to their adjustability and recoverability. However, the existing negative stiffness multistable curved dome is limited in its form and assembly flexibility. Therefore, this study proposes a design for a self-supporting negative stiffness multistable curved dome based on the cosine function. Finite element simulation was employed to investigate the force-displacement characteristics, steady-state behavior, and stiffness of individual units and the overall system. Furthermore, the impact of the curved dome’s height and the supporting part’s height on the steady-state properties of the structure was analyzed. Subsequently, an optimization algorithm based on response surface methodology was utilized to determine the optimal parameters for the unit. Additionally, 3D printing technology was employed to fabricate a twin-unit system using TPU material, followed by conducting quasi-static compression experiments and comparing the results with simulation data. The results indicate that the self-supporting curved dome, compared to the existing thick-encircled curved dome, facilitates easier attainment of a bistable state. By effectively controlling the height of the curved dome and the supporting structure, a bistable as well as a tri-stable state can be achieved. During the compression process, the system’s stable state can be altered, and the positive stiffness increases as compression progresses. Both parallel and flipped connections demonstrate the buckling process of each unit during loading and its tri-stable state. The self-supporting cosine curved dome enables more flexible combinations and superposition of multiple units compared to the existing thick encircled curved dome. The self-supporting cosine curved dome provides a new structure for programmable and intelligent control of structural performance and offers a promising direction for the advancement of multistable structures.关键词：Cosine curved dome;Negative stiffness;Multistable;Metamaterial;Bistable7|5|0更新时间：2025-11-26
·Design·Calculation·
- 摘要：The exploration of oil and gas resources is gradually shifting from gasoline or diesel-driven to electric-driven. However, traditional mountain geophysical electric drilling rigs generate significant vibration during operation, which seriously affects their working stability. Based on this, mountain geophysical electric drilling rigs were taken as the research object, and a combination of finite element simulation analysis and experiments was adopted to conduct vibration stability analysis and structural optimization of the electric drilling rigs. The simulation results show that the 7th, 8th, and 9th order natural frequencies of the electric drilling rig before optimization all fall within the resonance range, and the maximum vibration displacement occurs on the mast with a maximum displacement of 5.9 mm along the X-axis, which seriously affects the stability of the drilling rig. After optimizing the reducer type, base structure, and tie rod position of the drilling rig, the maximum natural frequency of the rig is reduced by 22.6% compared with that before optimization, all lying outside the resonance range; meanwhile, the maximum vibration displacement along the X-axis is 2.9 mm, The maximum vibration displacement along the X-axis is 2.9 mm, which is a 50.8% decrease compared with that of the drilling rig before optimization. The field tests show that after the drilling rig operates stably, its torque fluctuates slightly around 670 N·m, and the vibration accelerations of the mast in the X, Y, and Z directions stably fluctuate within the ranges of ±0.37, ±0.25 and ±0.04 m/s² respectively. No resonance occurs when the drilling rig works normally. This study solves the resonance problem of mountain geophysical electric drilling rigs during operation and can provide a reference for the research and development of green and efficient oil and gas exploration equipment.关键词：Mountain geophysical electric drilling rig;Vibration;Modal analysis;Harmonic response analysis;Structural optimization13|6|0更新时间：2025-11-26
- 摘要：In order to find a design solution that meets all the performance requirements while enabling the minimal trade-offs between different objectives, the bi-level integrated system collaborative optization (BLISCO) method based on approximate models is applied to the optimal design of the electric shovel structure. Firstly, a parametric model of the electric shovel was created, sample points were collected through a design of experiments that were used to screen design variables and approximate models of working devices, then a mathematical model for multi-objective optimization was developed by combining the approximate model with BLISCO method, multi-objective optimal design of the electric shovel working device was carried out at the second-generation non-dominated genetic algorithm and sequential quadratic programming were used at the system level and subsystem level, respectively. The optimized parameters were simulated again, and the results show that while solving the above problems, the hoist force and crowd force were reduced respectively by 5.4% and 6.13%, and the angle between the stick and the wire rope was increased by 1.4%. Finally, the electric shovel working device test platform before and after the optimization was built for testing and the correctness of the optimization results was verified.关键词：Mining electric shovel;Working device;Structural optimization;Multi-objective optimization10|8|0更新时间：2025-11-26
- 摘要：In the fatigue test of aircraft wing structural components, the fatigue design loads need to be optimized so as to reduce the bending, shear and torsion load errors applied during the test. Firstly, taking the full-scale aileron as the research object, the fatigue test load optimization model was established; then the objective function was solved by using the weighted summation method, and the optimized load at each loading point were obtained. The results show that the load is more suitable for loading design than the load assigned by the minimum energy method, and the load distribution is closer to the design load. Finally, the full-scale aileron fatigue test was designed and carried out, and the test strains were basically the same as the calculated results. It proves that the model can be used for fatigue test load optimization of large-scale components.关键词：Fatigue test;Full-scale aileron;Load optimization;Objective function10|4|0更新时间：2025-11-26
- 摘要：In view of some unstable factors in the working process of automatic expansion device of cables, such as the hydraulic cylinder support and frame were easy to deform, the optimization design was carried out. Static analysis of the automatic expansion device of the cable, finite element analysis of the hydraulic cylinder support and frame based on Workbench were carried out, the modal analysis was used to verify the establishment model, the optimization design of the finite element analysis results was carried out, the model parameterization, the design variables sensitivity analysis were carried out, and the Latin hypercube sampling method was used to pick points. The multi-objective function was optimized by multi-objective optimization genetic algorithm (MOGA), and then the initial data was compared with the optimization results. The results show that the maximum equivalent stress and maximum deformation of hydraulic cylinder support is reduced by 24.95% and 19.03% respectively under mass reduction conditions. The maximum deformation of the frame is increased by 26%, and the maximum stress is reduced by 42%, which effectively improves the stable operation of the automatic expansion device.关键词：Expansion device;Static analysis;Workbench finite element analysis;Modal analysis;Optimal design9|4|0更新时间：2025-11-26
- 摘要：In the screening of optimization design regions for subway car body structures, the sensitivity method is often used; however, its operation process is complex and cumbersome, and it cannot be quickly applied to the design of car body structures. To address this issue, based on the stiffness contribution theory and on the premise that the accuracy of the finite element model was verified through experiments, the local stiffness and global stiffness of the aluminum alloy subway car body were combined to quickly determine the main optimization regions of the car body. A method integrating topology optimization and size optimization was adopted to conduct a secondary optimization design study on the car body structure. The structural performance of the optimized car body fully complied with the EN 12663 standard: the mass of the optimized car body was reduced by 5.34%, the 1st-order vertical bending frequency was increased by 16%, and other modal frequencies were also significantly improved. This optimization provides a technical reference for the optimization design of other subway car body structures.关键词：Subway car body;Stiffness contribution degree;Topology optimization;Size optimization10|7|0更新时间：2025-11-26
- 摘要：Aimed at the problems of unbalanced adsorption force and weight, severe magnetic flux leakage, and low adsorption efficiency of permanent magnet assemblies in traditional wall-climbing robots, to improve their magnetic adsorption performance on steel walls and meet the operation requirements in complex environments such as ships and tower drums, a study on the design and optimization of Halbach permanent magnet assemblies was carried out. N40M neodymium-iron-boron and Q235 steel were selected as the permanent magnet and yoke materials respectively, and a trapezoid-like Halbach permanent magnet assembly was designed. A yoke was added on the upper side to guide magnetic induction lines and reduce magnetic flux leakage, while no yoke was arranged on the side. Based on Maxwell's equations and the stress tensor method, a finite element simulation model of adsorption force was established. The control variable method was adopted to systematically analyze the influences of assembly length, width, thickness, and yoke thickness. Under size constraints, parameters were optimized via the nonlinear programming method of moving asymptotes (MMA) algorithm. Finally, a Shimadzu AGX-V2 tensile testing machine platform was built, loaded at a speed of 0.2 mm/s with equipment gravity deducted, to verify the simulation results.After optimization, the adsorption force was increased from 3 500.6 N to 3 755.3 N, with an increase of 7.28%. The test and simulation curves showed a consistent trend, and the maximum adsorption force deviation was 8.1%, which verified the accuracy of the simulation model and provided a basis for the optimization of the adsorption system of wall-climbing robots.关键词：Halbach;Wall-climbing robot;Permanent magnet componet;Finite element simulation;Structure optimization7|6|0更新时间：2025-11-26
- 摘要：During the operation of inclined elevators, their safety braking systems were identified as key factors affecting the safety and reliability of the equipment. To address the characteristics of dynamic fault occurrence and uncertain fault rate in the safety braking systems of inclined elevators, a reliability analysis method for such safety braking systems based on the fuzzy dynamic fault tree (FDFT) was proposed. The fault rates of the bottom events in the safety braking systems were expressed based on fuzzy mathematics theory. Combined with the dynamic fault tree analysis (DFTA) method, the dynamic fault tree of the inclined elevator safety braking system was divided into static subtrees and dynamic subtrees. For the static subtrees, static OR logic gates were used to solve the fuzzy fault probabilities of events; for the dynamic subtrees, the fuzzy transition rates of different states in the Markov model were adopted to obtain the time-varying failure rate function of the safety braking system. Subsequently, the membership functions of the fault failure probability of the safety braking system at different operation times were derived, realizing the dynamic reliability analysis of inclined elevator systems under the condition of uncertain fault rates.Based on the calculation principle of fuzzy probability importance, the probability importance ranking analysis of the bottom events in the safety braking system was conducted, provided a basis for the regular inspection and maintenance of the safety braking systems of inclined elevators is provided by this research.关键词：Fuzzy mathematical theory;Dynamic fault tree;Inclined elevator safety brake system;Markov model;Fuzzy probability of significance4|6|0更新时间：2025-11-26
- 摘要：Wheels degraded during normal operation due to the coupling effect of multiple factors such as wear and impact. However, most existing studies only considered the influence of a single factor and regarded the failure threshold as a fixed value, thus failing to accurately reflect the wheel degradation law.For this reason, a dependent competing failure model considering variable thresholds was proposed. The non-stationary Gamma process and extreme shocks were used to describe the natural degradation and shock process of wheels, respectively. It was assumed that the natural degradation increment caused by shocks was dependent on the shock amplitude. The shock failure threshold was set to follow a normal distribution, so as to characterize the random influence of natural degradation on the shock failure threshold. Case calculations were conducted based on the measured wear data of the wheel flange of a certain EMU, and a comparative study is carried out using the Monte Carlo simulation method. The results verify the feasibility and effectiveness of the proposed modeling method, which can provide a reference for the optimization of wheel maintenance cycles.关键词：EMU wheel;Dependent competitive failure;Random variable failure threshold;Reliability analysis;Extreme shock;Non-stationary Gamma process11|5|0更新时间：2025-11-26
·Optimization·Reliability·
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