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The working temperature of any 3D printer has a critical effect on process feasibility as well as the final quality of the product. In this respect, thermal analysis can provide a comprehensive understanding of operation parameters and optimization potential. This most certainly also is the case for the new layer-wise additive manufacturing system, selective thermoplastic electrophotographic process (STEP). In the present paper, we propose a 3D part-scale finite element thermal model for multi-materials which is developed in the commercial software Abaqus/CAE 2021. The reduced-order method, flash heating (FH), is adopted in the model to obtain good accuracy with acceptable simulation time. A specific analysis of the trade-offs between accuracy and CPU-time is carried out by varying the amount of lumping in the meta-layers in the FH method. Furthermore, we conduct an in-house experiment in which we use IR cameras for measuring temperatures during manufacturing, and the results are applied for model validation and calibration. We specifically compare measured and numerically predicted average surface temperatures when steady state is obtained after printing of each layer. Here we obtain a mean error up to 6% depending on the thickness of the meta-layers. Moreover, parametric studies show that pulse duration and heater intensity significantly influence both the surface and bulk temperature profiles, and this provides us with an increased understanding of the thermal behavior of the recently developed STEP process which in turn could make way for further process optimization. [ABSTRACT FROM AUTHOR]

This paper introduces an innovative Magnetic Switch (MFS) designed to control and alter magnetic flux within energy system components, offering an alternative to conventional power electronic devices. The MFS comprises a low-current control coil, a control core, and a high-density magnetic flux-carrying main core combined with a main coil energy system. In this novel magnetic configuration, when a low-power current excites the control coil, the magnetic flux in the main core (supplied by the main coil) decreases to nearly zero. Conversely, when the control coil disconnects from the power source, the magnetic flux within the main core attains its maximum value. This operation positions the MFS as a groundbreaking concept within magnetic-based energy systems, akin to transistors in power electronics. The main outcomes of the MFS concept are that it can vary the magnetic flux of the main core in the large range, and it is a fast magnetic switch with a simple and low power loss control circuit and an independent control coil from the main coil. Analytical studies thoroughly elucidate the performance and advantages of this proposed magnetic switch, substantiated by Finite Element Method simulations and experimental prototype outcomes. [ABSTRACT FROM AUTHOR]

In the heat insulation winding molding process of solid rocket motors, the pressure applied by the press roller directly affects the quality of the winding molding. Insufficient pressure can result in poor bonding quality and may cause defects. This paper aims to provide an optimal design of the press roller to improve the winding molding quality of the heat insulation. The effect of the cylindrical press roller on the pressure distribution was analyzed using the elastic foundation model and a finite element (FE) model, which was assessed by Hertz theory. Subsequently, the press roller was optimized to an elliptical concave design. The effect of the radius of the elliptical concave press roller on the pressure distribution was analyzed. A comparison of the effect of the elliptical concave press roller and the cylindrical press roller on the pressure distribution was conducted using the FE model. The results show pressure uniformity is significantly improved when the elliptical concave press roller is employed on the mandrel with the smallest radius. Additionally, the elliptical concave press roller increases the pressure at the edge of the tape, which reduces the risk of lifted edges and, thereby, improves the winding molding quality of the heat insulation. [ABSTRACT FROM AUTHOR]

Manipulating plasmonic chirality has shown promising applications in nanophotonics, stereochemistry, chirality sensing, and biomedicine. However, to reconfigure plasmonic chirality, the strategy of constructing chiral plasmonic systems with a tunable morphology is cumbersome and complicated to apply for integrated devices. Here, we present a simple and effective method that can also manipulate chirality and control chiral light–matter interactions only via strong coupling between chiral plasmonic nanoparticles and excitons. This paper presents a chiral plexcitonic system consisting of L-shaped nanorod dimers and achiral molecule excitons. The circular dichroism (CD) spectra in our strong-coupling system can be calculated by finite element method simulations. We found that the formation of the chiral plexcitons can significantly modulate the CD spectra, including the appearance of new hybridized peaks, double Rabi splitting, and bisignate anti-crossing behaviors. This phenomenon can be explained by our extended coupled-mode theory. Moreover, we explored the applications of this method in enantiomer ratio sensing by using the properties of the CD spectra. We found a strong linear dependence of the CD spectra on the enantiomer ratio. Our work provides a facile and efficient method to modulate the chirality of nanosystems, deepens our understanding of chiral plexcitons in nanosystems, and facilitates the development of chiral devices and chiral sensing. [ABSTRACT FROM AUTHOR]

This paper proposes a reinforced concrete (RC) boundary beam-wall system that requires less construction material and a smaller floor height compared to the conventional RC transfer girder system. The structural performance of this system subjected to axial compression was evaluated by performing a structural test on four specimens of 1/2 scale. In addition, three-dimensional nonlinear finite element analysis was also performed to verify the effectiveness of the boundary beam-wall system. Three test parameters such as the lower wall length-to-upper wall length ratio, lower wall thickness, and stirrup details of the lower wall were considered. The load-displacement curve was plotted for each specimen and its failure mode was identified. The test results showed that decrease in the lower wall length-to-upper wall length ratio significantly reduced the peak strength of the boundary beam-wall system and difference in upper and lower wall thicknesses resulted in lateral bending caused by eccentricity in the out-of-plane direction. Additionally, incorporating cross-ties and reducing stirrup spacing in the lower wall significantly improved initial stiffness and peak strength, effectively minimizing stress concentration. [ABSTRACT FROM AUTHOR]

Marine platforms are located in complex environments, and safety deteriorates throughout the day. It is necessary to analyze the jacket platform structure by the finite element method. Problems such as platform structure variation and fatigue corrosion lead to model deviation. In this paper, a finite element model correction method based on deep learning is proposed with a jacket platform as the engineering background. First, different platform design parameters are selected, and the corresponding fundamental frequencies are obtained by finite element simulation. Second, the input features are extended as necessary to increase the damage-sensitive information, with the nonlinear differences between the two reduced by an improved ResNet50 network. Finally, the correction values of the finite element model are obtained by combining the measured data with the inherent structural frequencies obtained by covariance-driven stochastic subspace identification (Cov-SSI). The results show that the error after correction is less than 4%, which can reflect the real marine platform state well. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and analyze a lowest-order locking-free weak Galerkin (WG) finite element scheme for the grad-div formulation of linear elasticity problems. The scheme uses linear functions in the interior of mesh elements and constants on edges (2D) or faces (3D), respectively, to approximate the displacement. An H (d i v) -conforming displacement reconstruction operator is employed to modify test functions in the right-hand side of the discrete form, in order to eliminate the dependence of the L a m e ´ parameter λ in error estimates, i.e., making the scheme locking-free. The method works without requiring λ ‖ ∇ ⋅ u ‖ 1 to be bounded. We prove optimal error estimates, independent of λ , in both the H 1 -norm and the L 2 -norm. Numerical experiments validate that the method is effective and locking-free. [ABSTRACT FROM AUTHOR]

This paper concerns the effects of electrodynamic forces that act on current paths that are part of high-grade industrial distribution switchgear. This work is composed of experimental and simulation sections. In the experimental section, the short-circuit tests are presented and the occurrence of electrodynamic forces are shown in a visible way. The formation of electrodynamic forces in the current circuits of electrical energy distribution systems is related to the flow of high currents, but mostly it is related to short-circuit currents. In order to highlight these phenomena, the detailed specification of the parameters during tests is displayed. In the simulation section, the physical phenomenon of electrodynamic forces is being captured by employing a detailed real-scale model of switchgear and current paths. Therefore, the authors proposed employment of the FEM (finite element method) in order to obtain values of electrodynamic forces acting on the current paths by executing the detailed 3D coupled simulation. The analysis of the results and aftermath effects of their interactions provided interesting conclusions that concerned the operation of such power distribution layouts in critical short-circuit conditions. [ABSTRACT FROM AUTHOR]

Modern aircraft are being equipped with high-voltage and direct current (HVDC) architectures to address the increase in electrical power. Unfortunately, the rise of voltage in low pressure environments brings about a problem with unexpected ionisation phenomena such as arcing. Series arcs in HVDC cannot be detected with conventional means, and finding methods to avoid the potentially catastrophic hazards of these events becomes critical to assure further development of more electric and all electric aviation. Inductive sensors are one of the most promising detectors in terms of sensitivity, cost, weight and adaptability to the circuit wiring in aircraft electric systems. In particular, the solutions based on the detection of the high-frequency (HF) pulses created by the arc have been found to be good candidates in practical applications. This paper proposes a method for designing series arc fault inductive sensors able to capture the aforementioned HF pulses. The methodology relies on modelling the parameters of the sensor based on the physics that intervenes in the HF pulses interaction with the sensor itself. To this end, a comparative analysis with different topologies is carried out. For every approach, the key parameters influencing the HF pulses detection are studied theoretically, modelled with a finite elements method and tested in the laboratory in terms of frequency response. The final validation tests were conducted using the prototypes in real cases of detection of DC series arcs. [ABSTRACT FROM AUTHOR]

This paper describes the use of wireless smart sensors for examining the underlying mechanism for the wind-induced vibration of high-mast illumination pole (HMIP) structures. HMIPs are tall, slender structures with low inherent damping. Video recordings of multiple HMIPs showed considerable vibrations of these HMIPs under wind loading in the state of Kansas. The HMIPs experienced cyclic large-amplitude displacements at the top, which can produce high-stress demand and lead to fatigue cracking at the bottom of the pole. In this study, the natural frequencies of the HMIP were assessed using pluck tests and finite element modeling, and the recorded vibration frequencies were obtained through computer vision-based video analysis. Meanwhile, a 30.48 m tall HMIP with three LED luminaires made of galvanized steel located in Wakeeney, Kansas, was selected for long-term vibration monitoring using wireless smart sensors to investigate the underlying mechanism for the excessive wind-induced vibrations. Data analysis with the long-term monitoring data indicates that while vortex-induced vibration occurs frequently at relatively low amplitude, buffeting-induced vibration was the leading cause of the excessive vibrations of the monitored HMIP. The findings provide crucial information to guide the design of vibration mitigation strategies for these HMIP structures. [ABSTRACT FROM AUTHOR]

This paper presents a study on the numerical solutions of the Burgers' equation with forcing effects. The article proposes three hybrid methods that combine two-point, three-point, and four-point discretization in time with the Galerkin finite element method in space (TDFEM2, TDFEM3, and TDFEM4). These methods use backward finite difference in time and the finite element method in space to solve the Burgers' equation. The resulting system of the nonlinear ordinary differential equations is then solved using MATLAB computer codes at each time step. To check the efficiency and accuracy, a comparison between the three methods is carried out by considering the three Burgers' problems. The accuracy of the methods is expressed in terms of the error norms. The combined methods are advantageous for small viscosity and can produce highly accurate solutions in a shorter time compared to existing numerical schemes in the literature. In contrast to many existing numerical schemes in the literature developed to solve Burgers' equation, the methods can exhibit the correct physical behavior for very small values of viscosity. It has been demonstrated that the TDFEM2, TDFEM3, and TDFEM4 can be competitive numerical methods for addressing Burgers-type parabolic partial differential equations arising in various fields of science and engineering. [ABSTRACT FROM AUTHOR]

The study presents state-of-the-art requirements verification process for the prediction of the stability of the multi-staged deep excavation in submerged soft soil retained by stell sheet pile walls structures applied at the development of elasto-plastic finite element calculation method performed from Cast3M and Plaxis FE codes. Optimization numerical calculation results are proposed for retained walls design and construction on the basis of the horizontal displacement, earth and water pressures measurements. The transformation of the geometry and stiffness of the stell sheet pile walls to the retaining walls of an equivalent bending stiffness on the one hand and regular geometric shapes allowed in this paper to overcome the difficulties of modelling these stell sheet pile walls in 2D with irregular shapes. The horizontal deflection of the wall, the vertical displacement behind the walls, and the settlement of the excavation bottom are given. They have been compared by those obtained by various authors around the world. The results of this approach are satisfactory in view of the horizontal displacement curves obtained on the stell sheet pile walls compared by the measures. [ABSTRACT FROM AUTHOR]

Femoral fractures are frequent in adolescents and children, and most fractures occur within the centre of the bone, typically referred to as the femur shaft. Plate and screws are ideal fixation methods for femoral fractures close to the articular surfaces. When using plates and screws, estimating the load on the plates and screws before starting treatment is important. The primary focus of this paper is the examination of fixation plates utilized in the treatment of femur bone fractures. The study employs the finite element method to conduct this analysis. Initial modelling of the femur bone is executed through the utilization of CATIA V5 software. Subsequently, the investigation transitions to the ANSYS R14.5 environment, where more in-depth analysis is carried out. The modelling of the fracture fixation plates is done on commercially available CAD software CATIA V5. The stress distribution of different biomaterials in the bone plate system is calculated when the system is subjected to compressive loads with varying healing times. Here we have used stainless steel (SS316-L), titanium alloy (Ti6Al4V) and magnesium alloy (AZ31). More focus was given to the magnesium alloy. Here a fracture gap of 1mm gap was taken for analysis. A comprehensive compressive force amounting to 750 N was applied to the bone-plate assembly during the simulation. This force magnitude corresponds to the approximate weight of an average human body. [ABSTRACT FROM AUTHOR]

Nowadays, attention to railways has been increased as one of the important transportation methods. Various factors can cause longitudinal forces on the railway tracks, so the most important factors are the temperature changes due to the rail contraction and expansion (thermal forces), train braking system forces and acceleration, etc. Increasing longitudinal force can lead to buckling phenomena in railway tracks. In this paper, the effects of tensile and compressive longitudinal forces on the parameters of rail, sleeper, and ballast layers under vertical moving loads are investigated by using the finite element method. In this regard, by performing sensitivity analyses for different values of longitudinal forces and train speeds dynamic responses (displacement, velocity, and acceleration) of railway track components like rail, sleeper, and ballast have been studied. The results show that increasing the values of longitudinal axial force from -2000 [kN] up to 2000 [kN] as well as increasing the train speed from 10 [m/s] (36 [km/h]) up to 100 [m/s] (360 [km/h]) increases the rail displacement and velocity in the range of 25% up to 37% also the rail acceleration in the range of 9% up to 14%. The velocity and acceleration of the sleeper also the ballast velocity increase in the range of 24% up to 30% and 7% up to 9%, respectively, by increasing the speed of the train from 10 [m/s] (36 [km/h]) to 100 [m/s] (360 [km/h]) in all three modes without applying axial force, considering compressive and tensile one in the train-track interaction system. [ABSTRACT FROM AUTHOR]

This paper investigates the instability and buckling characteristics of a porous microplate under the influence of electrostatic fields, taking into account the implications of the intermolecular Casimir forces. Employing the modified couple stress theory, this research formulates equations that encapsulate the interplay between electrostatic and Casimir forces within porous plates. The analysis integrates distributed support loads, employing both Galerkin mode summation and finite element methods to solve static deformation equations and determine pull-in instability voltages and buckling loads. A novel approach is introduced, and equilibrium relationships are derived with respect to displacement to determine both the buckling load and instability voltage. This study effectively compares classical and non-classical theories, scrutinizing the effects of dimensionless length scale parameters and porosity ratios on maximum displacement, pull-in instability voltages, and buckling loads. The results demonstrate that the analytical method converges swiftly and aligns with the findings of the finite element method. The method for deriving equilibrium relationships proves to be accurate in predicting both instability voltage and buckling load. Additionally, the instability voltage exhibits an almost linear relationship with variations in the percentage of porosity, and similarly, the buckling load undergoes linear changes with alterations in porosity percentage. Hence, formulas for the linear relationships are calculated for both of these associations. [ABSTRACT FROM AUTHOR]

The paper presents the results of computational analysis of the stress-strain state of reinforced concrete spans of the railway (single-track railway line) overpass over the highway, under specified loads using spatial finite element models. The static load consists of a cohesion of three TEM-18 diesel locomotives and two loaded gondola cars (up to 25 tons per axle). The purpose of this study was to ensure reliable and safe operation of artificial structures on the railroads, as there is a constant increase in transit freight trains from China through the territory of Kazakhstan to near and far abroad, and often the load on the axle reaches 25 tons, and sometimes larger values – up to 27 tons per axle. The results of the study are recommended to be used for inspections and tests of typical girder bridge spans, as well as in the case of monitoring their technical condition with increasing operational loads. [ABSTRACT FROM AUTHOR]

Higher-order theories have a broad range of successful applications but also suffer from localization instability and mesh-size dependency when modeling quasi-brittle materials such as concrete with strain-softening behavior. To overcome the above difficulties, this paper proposes a fracture energy regularization method with a unified, consistent crack bandwidth specifically tailored for higher-order beam theories. The Carrera unified formulation (CUF) is applied to develop scalable structural theories and related finite elements. To evaluate the accuracy of the new crack bandwidth, three typical experimental quasi-static benchmarks of pure concrete structures are utilized. A modified Mazars damage model with tensile and compressive softening laws is implemented in these benchmarks. The comparison between numerical and experimental results demonstrates that the proposed method can accurately determine the correct crack bandwidth and preserve the dissipated energy per unit area of a fracture surface. Moreover, this robust estimation of crack bandwidth reduces the mesh dependency in general, ensuring the high efficiency of the CUF model. [ABSTRACT FROM AUTHOR]

An implicit limit state function is predicted with a support vector machine (SVM) for reliability analysis of engineering structures to reduce the number of finite element analyses. The accuracy and predictability of the SVM method are reduced considerably by noise in data. In this paper, density-based spatial clustering of applications with noise (DBSCAN) is applied to reduce the noise in training samples for SVM regression. Then, the SVM model is linked with Monte Carlo simulation (MCS) to find out the reliability of the engineering structures. Four different examples of static and dynamic problems are solved to show acceptability and efficiency of the proposed method. It is observed that the proposed method is suitable for a smaller number of performance function calls. Direct MCS, artificial neural network-based MCS and response surface methods have been used to examine the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

This paper proposes a local resonance-type pentagonal phononic crystal beam structure for practical engineering applications to achieve better vibration and noise reduction. The energy band, transmission curve, and displacement field corresponding to the vibration modes of the structure are calculated based on the finite element method and Bloch-Floquet theorem. Furthermore, an analysis is conducted to understand the mechanism behind the generation of bandgaps. The numerical analysis indicates that the pentagonal unit oscillator creates a low-frequency bandgap between 60–70 Hz and 107–130 Hz. Additionally, the pentagonal phononic crystal double-layer beam structure exhibits excellent vibration damping, whereas the single-layer beam has poor vibration damping. The article comparatively analyzes the effects of different parameters on the bandgap range and transmission loss of a pentagonal phononic crystal beam. For instance, increasing the thickness of the lead layer leads to an increase in the width of the bandgap. Similarly, increasing the thickness of the rubber layer, intermediate plate, and total thickness of the phononic crystals results in a bandgap at lower frequencies. By adjusting the parameters, the beam can be optimized for practical engineering purposes. [ABSTRACT FROM AUTHOR]

This paper provides a comparison between the conventional Electromagnetic Forming (EMF) technique and the novel Electromagnetic Hydraulic Forming (EMHF) approach. The EMHF involves the use of finite element analysis coupled with the EM and arbitrary Lagrangian–Eulerian techniques analyzed through LS-DYNA. In the free-bulge configuration, EMF is influenced by the forming coil, resulting in a dead zone and uneven forming. Additionally, EMF can only be used to shape materials with high electrical conductivity. In contrast, EMHF, driven by induced hydraulic pressure from the electromagnetic field-affected drive sheet, is independent of the electrical conductivity of the material and produces dome-shaped workpieces. For rectangular die shapes, EMF is prone to collision owing to the acceleration of the blank, which results in a reduced quality owing to bouncing. However, EMHF exhibits no bouncing effect and successfully achieves the target shape in most cases. The two techniques differ in the strain rate, with EMF at 4850/s, whereas EMHF operates at approximately 1250/s. Despite being slower, EMHF is still a high-speed forming technique. In conclusion, EMHF is a promising technique capable of addressing the shortcomings of conventional EMF and achieving improvements in forming processes. [ABSTRACT FROM AUTHOR]

This paper presents the results of research work on the revised design of a deep hole boring tool. The study was divided into three stages: theoretical, experimental and operational. In the theoretical part, a 3D model of the actual boring bar was created, which was subjected to strength tests using the Finite Element Method (FEM), and then prototypes of new deep hole boring tools were made with structural modifications to the shank part of the tool. For the polymer concrete core of a shank, there was a 14.59% lower displacement, and for the rubber-doped polymer concrete (SBR—styrene butadiene rubber) core of a shank there was a 4.84% lower displacement in comparison to the original boring bar. In the experimental part of the study, the original boring bar and the prototypes were subjected to experimental modal analysis and static analysis tests to compare dynamic and static properties. In the operational part of the study, boring tests were carried out for various workpiece materials, during which the basic parameters of the surface geometric structure (SGS), such as roughness Ra and Rz, were studied. Despite the promising preliminary results of the theoretical and experimental studies, using the described modifications to the boring bar is not recommended. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the effect of the geometry of the end-coil transition zone on the material stress state of a machined compression spring with a rectangular wire cross-section. The literature relationships for determining the stresses in rectangular wire compression springs neglect the effects associated with the geometry of this zone. A series of non-linear numerical analyses were carried out for models of machined compression springs with a wide range of variation in geometrical parameters. The results of these analyses were used to develop a computational model to estimate the minimum value of the rounding radius ρmin, which ensures that the stresses in this zone are reduced to the level of the maximum coil stresses. The model is simple to apply, and allows the radius ρmin to be estimated for springs with a spring index between 2.5 and 10, a helix angle between 1° and 15°, and a proportion of the sides of the wire section between 0.4 and 5. [ABSTRACT FROM AUTHOR]

The paper concerns the numerical modelling of a new slim-floor system with innovative steel–concrete composite beams called "hybrid beams". Hybrid beams consist of a high-strength TT inverted cross-section steel profile and a concrete core made of high-performance concrete and are jointed with prestressed hollow core slabs by infill concrete and tie reinforcement. Such systems are gaining popularity since they allow the integration of the main structural members within the ceiling depth, shorten the execution time, and reduce the use of concrete and steel. A three-dimensional finite element model is proposed with all parts of the system taken into account and detailed geometry reproduction. Advanced constitutive models are adopted for steel and concrete. Special attention is paid to the proper characterisation of interfaces. The new approach to calibration of damaged elastic traction–separation constitutive model for cohesive elements is applied to concrete-to-concrete contact zones. The model is validated with outcomes of experimental field tests and analytical calculations. A satisfactory agreement between different assessment methods is obtained. The model can be used in the development phase of a new construction system, for instance, to plan further experimental campaigns or to calibrate simplified design formulas. [ABSTRACT FROM AUTHOR]

This paper investigates the feasibility of a proposed underground gas storage facility. Based on S gas storage, a large-scale 2D hydromechanical coupling FEA model is established to explore the geo-mechanical properties of S gas storage under a multi-cycle alternating injection and production and validated by the interference logging test. To account for the damage development of fault damage area under the influence of seepage-stress coupling, the soil adopts the Mohr–Coulomb constitutive assumption. Additionally, a zero-thickness cohesive element is proposed as a mechanical model to simulate the fault gouge. The mechanical parameters of zero-thickness cohesive elements are verified by a ring shear test and a preliminary FE model. Thereafter, another refined conceptual finite element (FE) model considering the fault damage area, fault core, water-containing damaged area, overburden damaged area, and the contact model between different damaged areas of the fault and the fault core is developed and validated. The simulation results demonstrate that the initial seal ability of the caprock and faults remains intact. Specifically, (i) the maximum caprock and ground displacements are 8.5 cm and 5.4 cm, respectively. (ii) The most significant slip distance is 0.125 mm, indicating that, leakage under the action of multi-period alternating injection–production, the S aquifer structure had no fault activation and caprock. (iii) The risk of fault activation is higher for high-angle faults compared to low-angle faults. Low-angle faults are more susceptible to shear slip. Providing a scientific reference for the feasibility study of gas storage. [ABSTRACT FROM AUTHOR]

Currently, in some domestic and foreign mines, the backfill drilling pipeline experiences a rupture phenomenon even when the wear degree is low. This results in a delay in production due to the filling becoming 'sick'. This paper presents, for the first time, the damage mechanism from a mechanical perspective and re-derives the anti-extrusion strength model of the backfill drilling pipeline. We investigate the influence of the law on the anti-extrusion strength of pipelines from the perspective of strata and cement rings. We then verify the theoretical and simulation results through engineering examples. The results demonstrate that the Mises stress criterion is a suitable modification principle for the anti-extrusion strength model of the backfill drilling pipeline. The anti-extrusion strength of the pipeline is related to the elastic modulus and Poisson's ratio of the stratum, and the thickness of the cement ring. It is negatively affected by the depth of the stratum. For hard strata, a cement ring with a smaller elastic modulus is suitable, while for soft stratum, a cement ring with a larger elastic modulus is recommended. When the missing angle of the cement ring is less than 60°, the stress concentration factor increases up to 2.2. The stress unloading capacity of the cement ring ranges from 32.7% to 37.8%, and optimal performance of the cement ring is achieved when it has high strength and low rigidity. The backfill filling pipeline of a copper mine abroad was destroyed due to external extrusion force exceeding its anti-extrusion strength value. The modified pipeline anti-extrusion strength model is 18.2% higher than the pipeline API strength value. This finding can inform the design of the backfill filling pipeline for China's kilometer-deep wells in the future. [ABSTRACT FROM AUTHOR]

This paper presents the results of a numerical study of a planar antenna with a complex form factor. The antenna is based on a combination of two resonators, a disc resonator and a ring resonator. The feeding of the ring resonator is performed using a coplanar structure: pointwise by galvanic contact between the central conductor of the coplanar line and the ring resonator and by distributed electromagnetic coupling of the ring resonator and the aperture of the outer conductor of the coplanar line. The antenna was placed over a metal plane whose geometric dimensions were significantly larger than those of the antenna to exclude the influence of edge diffraction effects. In numerical simulation a complex approach including the method of semi-open resonator and the finite element method (FEM) implemented within the commercial package HFFS was used. The dependences of spectral, energy and polarization characteristics on material constants and frequency parameter have been investigated. It was found that within the framework of single-parameter optimization it is impossible to simultaneously achieve a high level of all important parameters. The values of frequencies of spectral lines in the spectral characteristics of the antenna are found with a relative error not worse than 1200 Hz. Frequency ranges within which there is no degeneration of oscillation types are established. The distributions of surface currents on the metal elements of the antenna, allowing to determine the position of phase centers of excitation, are presented. It is shown that the proposed antenna can provide an acceptable level of matching both at fixed frequencies and in sufficiently wide local frequency bands, reaching 11% with respect to the center frequency of the sub-band. The boundary values of gain coefficients in frequency bands are established. The simulation results allow to predict effective radiation with formation of practically single-lobe radiation pattern and presence of elliptical polarization. [ABSTRACT FROM AUTHOR]

The present paper investigates static deformation, free vibration, and patch loading response of one-dimensional (1D) hexagonal quasicrystal (QC) plates by the symplectic method. The Hamiltonian system is established by utilizing the variational principle, and then the symplectic analytical solutions of the extended displacement and traction vectors are obtained with simply supported boundary conditions. Numerical examples illustrate the effect of stacking sequence on the bending deformation of multilayered plates made up of QC and crystal materials. Moreover, the effects of the patch region, frequency, and phonon-phason coupling elastic coefficients on the corresponding problems are investigated. The symplectic analytical solutions presented in the article can be further used as benchmarks for numerical methods, such as the finite integral transformation and finite element methods. • The Hamiltonian system for dynamic equations of 1D hexagonal QC is established using the variational principle. • Analytic solutions of 1D hexagonal QC are rationally derived by the symplectic method. • The static deformation, free vibration, and patch loading response of 1D hexagonal QCs plates are investigated. • Some numerical tests are illustrated to justify the symplectic method. [ABSTRACT FROM AUTHOR]

• An accurate algorithm is presented for transcranial magneto-acoustic-electrical stimulation. • Unstructured mesh used in mesh discretization facilitates the pre-processing. • Our algorithm possesses higher calculation accuracy and faster convergence rate. • The developed model can achieve superior computational efficiency. • The proposed method is insensitive to mesh distortion. In this paper, a numerical method for simulating transcranial magneto-acoustic-electrical stimulation (TMAES) is presented. The smoothed finite element method (SFEM) is applied to calculate the magnetic field and the Rayleigh integral (RI) is used for solving the ultrasonic field. Three-node triangular and four-node tetrahedral elements are set as the background cells for constructing the smoothing domains (SDs). A gradient smoothing technique (GST) is applied over each SD to obtain the magnetic flux density. The discretized system equations are obtained by using the generalized smoothed Galerkin weakform. To solve the sound pressure, the ultrasonic transducer is discretized into a series of micro-elements. The acoustic pressure in the problem domain is then equal to the superposition of that generated by the individual micro-element. Finally, the current density can be calculated by the magneto-acoustic coupling effect. Numerical examples demonstrate that SFEM can improve accuracy, convergence rate, and efficiency to 10, 1.8, and 4 times those of FEM, respectively. In the calculation of coupled fields, SFEM-RI also improves the accuracy by 2.5 times. Additionally, the presented method possesses the property of insensitivity to mesh distortion. [ABSTRACT FROM AUTHOR]

This paper introduces an improved Halpin–Tsai model to predict the mechanical, thermal, and electrical properties of silicon-carbide-reinforced polypropylene composites. The model considers the influence of porosity and corresponding silicon-carbide volume fractions and derives relationships between material property shape factors and the aspect ratio, silicon-carbide volume fraction, and porosity. The improved model's predictions exhibit errors of 4.00% for mechanical properties, 2.13% for thermal properties, and 2.24% for electrical properties when compared to finite element analysis. This study demonstrates that the improved Halpin–Tsai model can effectively predict the properties of silicon-carbide-reinforced polypropylene composites, aiding in the design and optimization of these materials. [ABSTRACT FROM AUTHOR]

This paper reports a novel piezoelectric quartz crystal pressure sensor with a double-ended tuning fork (DETF) resonator. The key design is the resonator beams with a continuously variable section shape. Different from the traditional DETF with straight beams or the one with variable sections with steps, this design can improve sensitivity effectively. Theoretical analysis indicates that the sensitivity will increase with a decrease in beam width. Resonant pressure sensors with three different DETFs are designed and analyzed by finite element analysis software. Simulation results show that the sensitivity of this design is 162.27 Hz/MPa. This sensor has a typical structure, which includes three parts: the diaphragm, DETF resonator, and back-cavity structure. Quartz MEMS processes have been used in fabrication. The three parts are bonded together by vacuum glass frit sealing process. Test results of this sensor show that the natural frequency is 44.709 kHz with a quality factor of 12 717. The sensitivity is 155.6 Hz/MPa in the pressure range of 0–20 MPa. The results indicate that this novel design has advantages in sensitivity and fabrication processes. It will be a benefit for a high-performance and low-cost pressure measurement. [ABSTRACT FROM AUTHOR]

The small strain shear modulus is an important characteristic of geomaterials that can be measured experimentally using piezoelectric sensors (bender elements). However, most conventional signal interpretation techniques are based on the visual observation of the output signal and therefore inherently subjective. Objective techniques also exist, like the cross-correlation of the input and output signals, but they lack physical insight, as they rely on the (incorrect) assumption that input and output signals are similar. This paper presents GeoHyTE, the first objective and physically consistent toolbox for the automatic processing of the output signal of bender element sensors. GeoHyTE updates a finite element model of the experiment, iteratively searching for the small strain shear modulus that maximises the correlation between the experimental and numerical output signals. The method is objective, as the results do not depend on the experience of the user, and physically consistent, as the wave propagation process is modelled in full and signals of the same nature (output) are correlated. Moreover, GeoHyTE is nearly insensitive to grossly erroneous input by the user, both in terms of the starting point of the iterative maximisation process and refinement of the finite element model. The results obtained with GeoHyTE are validated against benchmark measurements reported in the literature and experimental data obtained by the authors. A detailed statistical analysis of the results obtained with GeoHyTE and conventional interpretation techniques is also presented. [ABSTRACT FROM AUTHOR]

The quest to reduce global plastic consumption has led to the emergence of biodegradable fiber-based composites as a promising sustainable replacement to conventional plastics in the food packaging industry. As the packaging sector is shifting more towards fiber-centric materials, thermoforming techniques for the 3D forming of the fiber-based materials, especially using complex mold designs, should be thoroughly researched to replace the conventional plastics in the industry. Finite element analysis of the deformation behavior of the paperboard during the thermoforming process and the factors that trigger the fracture of the composite layers were studied in the present work. The results show that 90° fiber orientation, 0.3 mm sheet thicknesses, and specific mold geometries can result in better forming results, thereby maximizing the potential of fiberbased materials in thermoforming. [ABSTRACT FROM AUTHOR]

The features of designing the frame of a universal container made of square pipes are presented in this paper. The two frame loading schemes are taken into account: the effect of vertical loading on the container frame when it is lifted by the upper corner fittings (I loading mode); the effect of longitudinal loading on the frame during transportation by the rail transport (II loading mode). Mathematical modeling was performed to determine the longitudinal loading acting on the container in the II loading mode. The determined acceleration is taken into account when constructing the schemes of force factors that arise in the frame. The strength of the frame was calculated using the finite element method, which was implemented in SolidWorks Simulation. The conducted research could contribute to creation of recommendations and developments regarding the design of modern structures of modular vehicles. [ABSTRACT FROM AUTHOR]

The cracking of ultra-long and large concrete structures with strong constraints is a key issue under the action of shrinkage and hydration heat. The length of section pouring during construction is one of the main parameters to control the cracking of concrete. In this paper, the shrinkage test of concrete specimens under the condition of coculture is carried out under the background of the landing gear slide test platform of large aircraft. The measured early shrinkage curve of the expanded concrete is obtained, and the finite element model is established. The effects of the casting thickness, mould temperature, and limited expansion rate on the stress and cracking of super-long and large concrete are studied. The results show that factors such as the casting thickness, mould temperature, and limited expansion rate have significant effects on the limited length of the section after pouring. When the casting thickness is increased by 200%, the limit of the section length is reduced by 42%. When the mould temperature increases by 66.7%, the section length limit decreases by 28.2%, while the value increases by 24.2%, with an increasing expansion rate of 75%. The relationship between the three parameters and the piecewise pouring length is approximately linear. The exact calculation of the section length limit of strongly constrained ultra-long mass concrete under different pouring thicknesses, mould temperatures, and limited expansion rates is derived, and a simplified calculation formula is also proposed through data regression analysis. The errors between them are less than 1.7%, which provides a basis for calculating the section length of strongly constrained ultra-long mass concrete construction. [ABSTRACT FROM AUTHOR]

This paper proposes a simple yet accurate finite element (FE) formulation for the thermomechanical analysis of laminated composites and sandwich plates. To this end, an enhanced first-order shear deformation theory including the transverse normal effect based on the mixed variational theorem (EFSDTM_TN) was employed in the FE implementation. The primary objective of the FE formulation was to systematically interconnect the displacement and transverse stress fields using the mixed variational theorem (MVT). In the MVT, the transverse stress field is derived from the efficient higher-order plate theory including the transverse normal effect (EHOPT_TN), to enhance the solution accuracy, whereas the displacement field is defined by the first-order shear deformation theory including the transverse normal effect (FSDT_TN), to amplify the numerical efficiency. Furthermore, the transverse displacement field is modified by incorporating the components of the external temperature loading, enabling the consideration of the transverse normal strain effect without introducing additional unknown variables. Based on the predefined relationships, the proposed FE formulation can extract the C0-based computational benefits of FSDT_TN, while improving the solution accuracy for thermomechanical analysis. The numerical performance of the proposed FE formulation was demonstrated by comparing the obtained solutions with those available in the literature, including 3-D exact solutions. [ABSTRACT FROM AUTHOR]

Carbon-fiber-reinforced polymer (CFRP) composites are widely used in lightweight structures because of their high specific strength, specific modulus, and low coefficient of thermal expansion. Additionally, the unidirectionally arrayed chopped strand (UACS) laminates have excellent mechanical properties and flowability, making them suitable for fabricating structures with complex geometry. In this paper, the damage process of UACS quasi-isotropic laminates under tensile load was tested using acoustic emission detection technology. The mechanical properties and damage failure mechanism of UACS laminates were studied combined with finite element calculation. By comparing and analyzing the characteristic parameters of acoustic emission signals such as amplitude, relative energy, and impact event, it is found that acoustic emission behavior can accurately describe the damage evolution of specimens during loading. The results show that the high-amplitude signals representing fiber fracture in continuous fiber laminates are concentrated in the last 41%, while in UACS laminates they are concentrated in the last 30%. In UACS laminates, more of the damage is caused by matrix cracks and delamination with medium- and low-amplitude signals, which indicates that UACS laminates have a good suppression effect on damage propagation. The stress–strain curves obtained from finite element analysis agree well with the experiment results, showing the same damage sequence, which confirms that the model described in this research is reliable. [ABSTRACT FROM AUTHOR]

Lifting is to use lifting equipment to lift components and install them to the designated position. On the main structure, lifting equipment is used to transport the flue and transport the sectional flue to the designated position. Certain deformation will occur during the lifting operation of the flue due to its force condition, but it is not known whether it is elastic deformation or plastic deformation. Therefore, this paper analyzes the stress and strain of the flue during operation by finite element method, and observes and analyzes the influence of plastic deformation on the whole flue. [ABSTRACT FROM AUTHOR]

Aiming at the aerospace aircraft tie rod pipe fittings with indented riveted threaded bushing manufacturing, there are problems such as low connection strength, manufacturing cost and high weight, this paper innovates a new process of three-roll reduction and end extrusion thickening to form the aerospace thin-walled tie rods, and adopts the simufact finite element analysis (FEA) software to numerically analyse the forming process of the thin-walled fittings of A6061 aluminium alloy and analyse the equivalent plastic strain distribution, the change rule of the force-energy parameter, as well as the uniformity of the wall thickness in the process of rolling and squeezing, so that we can get the principle of rolling and squeezing forming and deformation rules of the thin-walled tie rods, and the results of the research provide the theoretical foundation for the domestic forming of the thin-walled tie rod pipe fittings. [ABSTRACT FROM AUTHOR]

As a widely used equipment in continuous casting process, the installation process of ladle rotary table is complicated and requires many installation equipment. According to the practical engineering application, this paper takes the installation device as the research object, and optimizes the original structure of the installation device. SolidWorks software was used to model the overall structure of the installation device, and the established model was imported into Hypermesh for mesh division, and finally into ANSYS for finite element analysis to compare the stress and deformation of the structure before and after optimization. The results show that the stress of the optimized structure is reduced to some extent, and the practical application requirements are met. [ABSTRACT FROM AUTHOR]

Due to their excellent thermal conductivity and sensitivity to temperature changes, special attention should be paid to the influence of temperature on steel-structure bridges. The temperature effect is complex, especially for unstable steel arch bridges with complex structural forms. This paper proposes an approximate method that measures the three-dimensional temperature field of the symmetrical arch rib with the two-dimensional temperature field of multiple sections. In addition, it converts the complex radiant intensity calculation of the special-shaped steel box arch rib into the calculation of numerous planar radiant intensities. It uses the ANSYS Workbench to establish the three-dimensional transient thermal analysis finite element model of the No. 2 steel box arch rib. The influence of seasons and arch rib direction on the temperature field of steel box arch ribs and the stress and deformation of steel box arch ribs under non-linear temperature effects were analyzed. The results show that the temperature changes in different seasons significantly impact the temperature changes in the arch ribs. The change in the azimuth angle of the arch rib has a significant impact on the temperature difference between the web plates on both sides of the arch rib; under the influence of the temperature field at the most unfavorable time in summer and winter, symmetrical stress concentration occurs in the arch foot area. Furthermore, the maximum vertical displacement is 13.9 mm and 10.8 mm, respectively. Finally, when the angle is 40°, the maximum temperature difference between the web plates on both sides is 6.9 °C. [ABSTRACT FROM AUTHOR]

In this paper is presented a two-dimension analytical model for linear permanent magnet inner armature double-sided synchronous motors (LPMIADSSMs). The flux density in all areas of the proposed machine is calculated based on the sub-domain method. According to this method, the machine areas are divided into eleven sub-regions such as first external, first mover, first PM, first air gap, first winding, stator, second winding, second air gap, second PM, second external and second mover, which sign as FE, FR, FP, FAG, FW, S, SW, SAG, SP, SE and SR. To find the flux density equations, it is mandatory to solve the extracted Maxwell equations and apply the boundary conditions between each two sub-regions, which lead to find the unknown coefficients for flux density in each sub-region. In addition, the influences of magnetization patterns, i.e., parallel, ideal Hal Bach, 2-segment Halbach and bar magnet in the shifting direction of the flux distribution and armature reaction (AR), are investigated. To validate the obtained results, the proposed model results are compared with those obtained from finite element method (FEM) and Maxwell software. [ABSTRACT FROM AUTHOR]

This paper presents a two-dimensional analytical model for brushless double-rotor flux-switching permanent magnet machines (BDRPFSPMM) with yokeless stator recognized as a type of partitioned-structure flux-switching permanent magnet that is an appropriate machine to be employed as the electric motor in industry. The most salient advantages of the proposed machine are low iron loss due to volume of iron in stator and high space of stator slot for winding. The radial and tangential components of the magnetic flux density due to permanent magnets and armature currents in each active domain of the machine, electromagnetic torque, self- and mutual inductance, unbalanced magnetic force (UMF), and local traction are calculated based on the subdomain method. Teethes on both rotor and stator structures are effective on magnetic quantities, so interactions of rotor and stator saliency are considered. The method is general for the magnetic field calculation with any combination of rotor- and stator-pole number. To validate the proposed model, the analytical outputs are compared with those obtained from the finite element method (FEM). [ABSTRACT FROM AUTHOR]

In order to reduce the cogging torque of a symmetrical V-type line-start permanent magnet synchronous (LSPMS) motor, this paper proposes a multi-objective optimization method based on the combination of design parameter stratification and response surface methodology (RSM). The optimal solution to the RSM model is acquired using the max–min ant algorithm. The permanent magnet width, pole opening angle, stator slot width, rotor axial length, and rotor tooth width are selected as optimization variables. The cogging torque and average torque are the optimization objectives. Finite element method (FEM) results show that the cogging torque is reduced by 71.5%, the torque ripple is reduced by 65.6%, and the average torque is improved by 12%. Finally, the effectiveness of the algorithm is verified with simulation results. [ABSTRACT FROM AUTHOR]

Estimating losses accurately for magnetic materials in power conversion circuits is a challenging task. Solving the partial differential equations in a complex geometry of inductive components such as filter-integrated transformers is an additional prominent challenge. While there are some commercially available finite element simulation tools that provide loss calculations in time-domain for multi-dimensional geometries of magnetic materials, the principle of analysis is not fully disclosed and less flexible for engineers to use. In this paper, we introduce a comprehensive method for systematically and flexibly applying time-domain dynamic loss equations to geometric finite element methods in multi-dimensions. The developed post-process framework for magnetic core loss calculations is coded in an open-source programming language, Python, and verified by comparison with analytical solutions for a filter integrated isolation transformer under a variety of operating conditions. Parallel processing is used to deal with the large datasets associated with element-by-element numerical calculations in the time domain. A high level of accuracy is achieved and verified. [ABSTRACT FROM AUTHOR]

This paper presents the results of a comprehensive investigation into the comparative analysis and design optimization of ferrite-based surface permanent magnet vernier machines (SPMVMs). While SPMVMs boast a simple mechanical structure and enhanced torque density attributed to the flux modulation effect, they suffer from a persistent challenge of low power factor. Several factors hinder the adoption of low-cost ferrite magnets in SPMVMs. First, ferrite magnets are prone to irreversible demagnetization, constraining the allowable range of magnet thickness. Second, the reduced residual magnetic flux density of ferrite magnets exacerbates the decrease in power factor and machine efficiency. Thus, achieving optimal performance in ferrite-based SPMVMs necessitates the careful selection of various design parameters. To address these issues, this study employs a surrogate-based metaheuristic optimization algorithm with adaptive sampling to identify the optimal solution. Additionally, the integration of a Halbach array is explored to further enhance the performance of the three-slot/two-pole SPMVM topology. Subsequently, two ferrite-based SPMVM baseline models—one with a conventional SPM structure and another with a Halbach magnet array—are thoroughly designed, optimized, and subjected to detailed performance analysis using the 2D finite element method. [ABSTRACT FROM AUTHOR]

The paper presents a new cost-effective magnetic circuit structure of a coreless permanent magnet synchronous motor (PMSM) with 16 poles and 12 coils for a mass production fan drive unit. 2D and 3D numerical models of the coreless PMSM were developed. Optimisation calculations were carried out using the field model of the machine. Multistage calculations were performed using the professional FEM package, ANSYS Maxwell and the author's proprietary finite element method (FEM) code. On the basis of the conducted tests and analysis of the obtained results, the "optimal" magnetic circuit structure of the PMSM motor was selected. The prototype motor was subjected to measurement to verify the developed models and the proposed design approach that takes advantage of finite element analysis (FEA). [ABSTRACT FROM AUTHOR]

Despite the many advantages of steel shear walls, such as high strength and stiffness, good ductility and high energy dissipation, the increase in the size of columns next to the steel shear walls is a drawback that affects the use of this system. In order to achieve an economic design while keeping design essentials and optimal performance, a novel steel shear wall system called "semi-supported steel shear wall (SSSW)" was proposed, in which the wall plate is attached to the secondary columns instead of the primary columns of the frame. The secondary columns are only responsible for creating the tension field in the plate and the lateral load rather than partnership in the toleration of gravity loads. In this paper, due to the lack of knowledge on the dynamic behavior of steel plate shear walls in general and SSSW in particular, the nonlinear dynamic behavior of SSSWs is investigated. The explicit finite element method is used for analysis and the results are verified by the laboratory test results. The results of the nonlinear dynamic analysis show that semi-supported shear walls have a very good dynamic performance in increasing stiffness and reducing the lateral displacement of the structure. The effects of various parameters of SSSW on its dynamic behavior are also investigated. [ABSTRACT FROM AUTHOR]

This paper aims to analyze and describe the geotechnical behavior of a piled raft foundation of a tall building (53 floors, 172.4 m high) through the monitoring of strains in the building's columns and piles, the stresses at the raft–soil interface, and the foundation settlements. Field and laboratory tests were performed, and associated with axisymmetric and three-dimensional finite element analysis to the assessment of the measured data. The monitoring of the pile strains suggests the occurrence of soil expansion, caused by the raft excavation process, up to approximately 6 months after the excavation was completed. The presence of different soil profiles under the raft, with different mechanical properties, affected the distribution of the foundation settlements and the pile loads. Initially, the average pile loads were concentrated in the perimeter elements, but, as the construction of the building evolved, they tended to become more uniform. The effect of the superstructure stiffness caused successive load redistributions in the columns, which contributed to the maintenance of the maximum angular distortion of the building within the allowable values and reduced the load difference between the piles positioned in opposite soil profiles. [ABSTRACT FROM AUTHOR]

With the rapid development of big data, the Internet of Things (IoT), and other technological advancements, digital twin (DT) technology is increasingly being applied to the field of bridge structural health monitoring. Achieving the precise implementation of DT relies significantly on a dual-drive approach, combining the influence of both physical model-driven and data-driven methodologies. In this paper, two methods are proposed to predict the displacement and dynamic response of structures under strong winds, namely, a Bayesian Neural Network (BNN) model based on Bayesian inference and a finite element model (FEM) method modified based on genetic algorithms (GAs) and multi-objective optimization (MOO) using response surface methodology (RSM). The characteristics of these approaches in predicting the dynamic response of large-span bridges are explored, and a comparative analysis is conducted to evaluate their differences in computational accuracy, efficiency, model complexity, interpretability, and comprehensiveness. The characteristics of the two methods were evaluated using data collected on the Forth Road Bridge (FRB) as an example under unusual weather conditions with strong wind action. This work proposes a dual-driven approach, integrating machine learning and FEM with GNSS and Earth Observation for Structural Health Monitoring (GeoSHM), to bridge the gap in the limited application of dual-driven methods primarily applied for small- and medium-sized bridges to large-span bridge structures. The research results show that the BNN model achieved higher R 2 values for predicting the Y and Z displacements (0.9073 and 0.7969, respectively) compared to the FEM model (0.6167 and 0.6283). The BNN model exhibited significantly faster computation, taking only 20 s, while the FEM model required 5 h. However, the physical model provided higher interpretability and the ability to predict the dynamic response of the entire structure. These findings help to promote the further integration of these two approaches to obtain an accurate and comprehensive dual-driven approach for predicting the structural dynamic response of large-span bridge structures affected by strong wind loading. [ABSTRACT FROM AUTHOR]

Cracking frequently encountered in railway bridges can lead to significant changes in bridge dynamic characteristics and further dynamic performance of train–bridge interaction (TBI) system. It is desirable to develop an effective method to understand the dynamic behavior of coupled train and cracked bridge systems. This paper proposes a framework for coupled vibration analysis of train and cracked bridge systems using multiscale finite element modeling. A multiscale bridge model adopting frictional surface–surface contact to characterize nonlinear breathing phenomenon of the crack is incorporated into the three-dimensional coupled TBI model. Subsequently, a multiloop numerical solution strategy is formulated to solve the established dynamic equation of coupled train and cracked bridge systems. The proposed framework is used to analyze the cracked beams presented in the literature, and the obtained and literature data are compared. Moreover, an actual heavy-haul railway bridge is taken as an illustrative example, in which vehicle dynamic response, bridge vibration, and train running safety index are calculated considering various crack types, train speeds, and track conditions. The results show that apart from the bridge displacement and acceleration, the presence of crack can have a large influence on the vehicle acceleration response, derailment factor, and offload factor. Differences larger than ±10% in the maximum dynamic indices associated with the intact and cracked bridges are observed, indicating the necessity of considering the crack damage in train–bridge coupled dynamic analysis. [ABSTRACT FROM AUTHOR]