Finite Element Method Analysis Research Articles

Effects of Out-of-Plane Deformation of the Base Plate on the Structural Behavior of an Exposed Column Base

This study explores the behavior of exposed column bases in concrete-filled steel tubular (CFST) and steel structures, with a focus on cases where base plates yield due to out-of-plane deformation. Understanding these mechanisms is crucial for improving the design and safety of these structures. Experimental tests and numerical analyses were conducted on four specimens to investigate their lateral load versus drift angle behavior. The tests demonstrated that base plates exhibited sufficient deformation capacities and enhanced hysteresis characteristics. Finite element method (FEM) analysis successfully traced the load–deformation relationships observed in the tests, providing detailed insights into stress distribution on the base plates. Based on these analyses, a simplified calculation method was proposed to evaluate the horizontal strength of exposed column bases. The proposed method showed excellent agreement with the test results, highlighting its potential as a practical tool for structural design.

Metamodel-based Hybrid Parametric Optimization with Static Prototype Validation for a Six-Axle Wheel Load Cell Design

The accurate measurement of forces and torques acting on a vehicle’s chassis, originating from wheel-pavement interactions, is essential for optimizing suspension systems, axles, and other structural components. A critical challenge in optimizing wheel load cell (WLC) design is to enhance sensitivity without compromising mechanical robustness. To address this question, this study developed a six-axis load cell designed to decouple force and torque measurements, achieving high sensitivity and reliability. The objective was to design an optimized WLC for multi-axis force measurement by maximizing sensitivity through a metamodel-based hybrid optimization framework. The methodology began with a fractional factorial Design of Experiments (DOE) to identify key parameters affecting load cell sensitivity and to define the optimization search space. This was followed by a dual-step parametric optimization process, utilizing the finite element method (FEM) to evaluate load cell performance and an inner-point optimization algorithm for convergence. After completing the DOE and FEM stages, the load cell was physically constructed and calibrated using a universal testing machine MTS 810, where experimental data closely matched simulation results, validating the design’s effectiveness. The main findings indicate that the optimized load cell can reliably measure six components, with a sensitivity increase of 14% compared to conventional designs. Numerical results from FEM analyses showed stress levels at 215 MPa, displacements around 0.16 mm, and a first-mode vibration frequency of 1351 Hz, meeting all structural integrity and performance requirements. Calibration confirmed minimal cross-talk effects, supporting the robustness of the final design. The developed load cell met optimal design criteria, showing substantial improvements in sensitivity and accuracy over existing designs, with potential applications in automotive, aerospace, and engineering testing.

Determination of the Ultimate Bearing Capacity of a Single Barrette Wall using FEA and Cubic Nonlinear Regression

This study analyzes the mechanical behavior of barrette walls under various load levels, a critical issue in the design and construction of structures subjected to large loads. The primary objective of the research is to determine the nonlinear relationship between load and settlement of barrette walls, as well as to assess the maximum load-bearing capacity of the walls under diverse loading conditions. The finite element analysis method was employed to simulate the detailed interaction between the barrette wall and the soil, combined with cubic and linear regression analysis techniques to establish the model of the relationship between load and settlement displacement. The research results reveal a nonlinear relationship between load and settlement of the wall, with an inflection point occurring at a load level of approximately 12,000 kN, where the change in settlement becomes more pronounced. The cubic regression equation achieved a coefficient of determination R² = 0.999, demonstrating the high accuracy of the model. The maximum load-bearing capacity of the barrette wall was determined to be 15,745.59 kN, providing a clear scientific basis for evaluating the load-bearing capacity of structures. The conclusions from this study affirm the importance of using finite element simulations in soil mechanics analysis and the design of structures subjected to large loads. The achieved results not only enhance understanding of the behavior of Barrette walls but also contribute to the development of new technical solutions and design methods, with the potential for wide application in the construction and geotechnical engineering sectors.

A finite element modeling and analysis method for ultra-high performance concrete

A finite element modeling and analysis method for ultra-high performance concrete

PROSTHESIS REPAIR OF ORAL IMPLANTS BASED ON ARTIFICIAL INTELLIGENC`E FINITE ELEMENT ANALYSIS

Dentists often suggest dental implants to replace missing teeth; nevertheless, mechanical issues can develop with these implants, which could lead to prosthesis replacement or repairs. When investigating implant systems' mechanical characteristics and stress distribution, finite element analysis (FEA) is a popular computational tool. In biomechanical investigations, this strategy is widely used. However, traditional FEA methods can be tedious and require expert expertise for accurate simulation and translation of results. To automate and simplify the process of mending oral implant prostheses, the article suggests a new framework called AI-FEA. The three primary parts that make up the suggested AI-FEA framework are 1. An AI-powered model creation module that utilizes data from medical imaging to autonomously construct 3D finite element designs that are unique to each patient. Utilizing deep learning approaches, this module segments and reconstructs three-dimensional geometries from computed tomography (CT) or cone-beam CT data using material properties and boundary conditions. 2. A FEA solver that runs simulations to test the way the implant system handles different loads. This component uses state-of-the-art numerical methods to model the implant and bone interface and determine stress distributions. 3. An AI-based decision support system that takes all that data and recommends the best way to fix the prosthesis. Combining FEA findings with patient-specific variables, this decision support system uses machine learning algorithms educated on an extensive dataset of implant failure instances and repair results to provide the optimal repair strategy. For patients experiencing issues with oral implants, the suggested AI-FEA framework might mean huge time and skill savings in prosthesis repair planning, leading to better, more individualized care.

Biomechanical evaluation of percutaneous compression plate and femoral neck system in Pauwels type III femoral neck fractures

BackgroundThe optimal treatment for Pauwels type III femoral neck fractures remains contentious. We aim to compare the biomechanical properties of three inverted cannulated compression screw (ICCS), femoral neck system (FNS), and percutaneous compression plate (PCCP) to determine which offers superior stability for unstable femoral neck fractures.Materials and methodsFinite element analysis and artificial bone models were used to establish Pauwels III femoral neck fracture models. They were divided into ICCS, FNS, and PCCP groups based on respective internal fixation assemblies. The models were subjected to vertical axial loads (2100 N) and torsional forces (10 N × mm) along the femoral neck axis in the finite element analysis. The primary outcomes such as the Z axis fragmentary displacements, as well as displacements and the von Mises stress (VMS) distributions of internal fixations, were analyzed. Additionally, the artificial bones were subjected to progressively increasing vertical axial pressures and torsional moments at angles of 2°, 4°, and 6°, respectively. The vertical displacements of femoral heads and the required torque values were recorded.ResultsFinite element analysis revealed that under single-leg stance loading, the maximum Z-axis fragmentary displacements were 5.060 mm for ICCS, 4.028 mm for FNS, and 2.796 mm for PCCP. The maximum displacements of internal fixations were 4.545 mm for ICCS, 3.047 mm for FNS, and 2.559 mm for PCCP. Peak VMS values were 512.21 MPa for ICCS, 242.86 MPa for FNS, and 413.85 MPa for PCCP. Under increasing vertical loads applied to the artificial bones, the average vertical axial stiffness for the ICCS, FNS, and PCCP groups were 244.86 ± 2.84 N/mm, 415.03 ± 27.10 N/mm, and 529.98 ± 23.08 N/mm. For the torsional moment tests, the PCCP group demonstrated significantly higher torque values at 2°, 4°, and 6° compared with FNS and ICCS, with no significant difference between FNS and ICCS (P > 0.05).ConclusionsFinite element analysis and artificial bone models indicated that PCCP offers the best compressive and rotational stability for fixing Pauwels type III femoral neck fractures, followed by FNS and then ICCS. No significant difference in rotational resistance was observed between FNS and ICCS in synthetic bones.Level of Evidence Level 5.

Error analysis of implicit-explicit weak Galerkin finite element method for time-dependent nonlinear convection-diffusion problem

This paper focuses on the exploration of an implicit-explicit (IMEX) weak Galerkin finite element method (WG-FEM) applied to a one-dimensional nonlinear convection-diffusion equation. Based on a special weak form featuring two built-in parameters, we propose the fully implicit-explicit discrete WG finite element scheme. The diffusion term is treated implicitly, while the nonlinear convection term is treated explicitly. The WG-FEM utilizes locally piecewise polynomials of degree k to approximate the primal variable within the element interiors, along with piecewise polynomials of degree k+1 for the weak derivatives. Optimal error estimates in the L2 norm for the fully discrete scheme are derived in the theoretical analysis. Furthermore, we conduct numerical experiments to illustrate the effectiveness and accuracy of the proposed scheme.

Prediction of axial compressive capacity and interpretability analysis of web perforated Σ-shaped cold-formed steel

The Σ-shaped cold-formed steel with web opening (ΣSCFSWWO) is a critical component in modern structural systems, and accurate calculations of its axial compressive capacity are essential for ensuring the overall stability and safety of structures. However, traditional finite element analysis (FEA) and experimental methods are often inefficient and require complex modeling techniques for capacity calculations. Moreover, the interaction between section design parameters and structural capacity remains unclear. This study integrates FEA, experimental methods, and machine learning to propose a novel approach for predicting capacity and analyzing parameter interpretability. A dataset comprising 1000 numerical simulation results and 260 experimental data points was established. Machine learning techniques, including BP (Backpropagation) neural networks, RBF (Radial Basis Function) neural networks, Decision trees, Random Forests, and XGBoost algorithms, were employed to develop predictive models for capacity. The SHapley Additive exPlanation (SHAP) method was utilized for interpretability analysis. Results indicate a good correlation between FEA and experimental outcomes, effectively simulating the mechanical behavior of the components. Comparative analysis reveals that the XGBoost model demonstrates the highest predictive accuracy and generalization capability. SHAP analysis elucidates the influence of various input parameters on axial compressive capacity predictions and clarifies the interactions among these parameters. This research provides a novel reference for calculating the axial compressive capacity of ΣSCFSWWO, and the proposed methodologies can be extended to other similar components.

Investigation of polymer injection molding using calcareous waste concrete powder and polyethylene

AbstractThis study fabricated composite materials using waste concrete powder (WCP) and linear low‐density polyethylene via injection molding to improve the resource value of polymer composites of waste concrete. The flexural strength and modulus of the composite material improved with increasing WCP content and did not decrease even at a WCP content of 60 wt%. Moreover, the effect of the WCP particle size on the mechanical properties of the composite was low for composites with a WCP content of 20 wt%. To investigate the effect of the WCP particle size on the mechanical properties of the composite material in detail, the von Mises stress distribution of the composite material with a WCP content of 20 wt% was analyzed using finite element method (FEM). The von Mises stress distributions of the composite materials were almost identical across all WCP particle sizes. The results from the experiment and FEM analysis suggested that the interfacial adhesion between the WCP and LLDPE is in good condition. Therefore, it can be concluded that injection molding using WCP and LLDPE is feasible and WCP shows promise as a reinforcement particle.Highlights Fabrication of plastic composite material using the WCP by injection molding. The flexural strength and modulus increased by adding the WCP. The effect of the WCP particle size on the mechanical properties was low. The Mises stress were almost identical at each WCP particle size. The WCP is promising reinforcement of flexural strength and modulus.

Research on magnetic force of magnetic seal in aero-engine

Aiming at the magnetic seal in an aero-engine accessory, the range of magnetic force required for the normal operation of the magnetic seal is analyzed. The finite element analysis method based on the Maxwell stress tensor method is used to calculate the magnetic force between the dynamic ring and the magnetic static ring in the magnetic sealing system. The magnetic force under different magnetization modes and gaps is tested by the magnetic measuring test bench, which verifies the correctness of the magnetic calculation method. The effects of permanent magnet material, permanent magnet magnetization direction, magnetic seal structural parameters, and working conditions on the magnetic force between the dynamic ring/magnetic static ring in the magnetic seal are analyzed. Under the same structure, the magnetic force of NeFeB35, SmCo28, Alnico5, and Ferrite as magnetic static rings is compared. The results show that NdFeB35 has the largest magnetic force, SmCo28 is second, Alnico5 and Ferrite are relatively small, and their magnetic forces are about 1/4 to 1/5 of the first two materials. When the rotor or the casing is moving axially, NeFeB35 and SmCo28 materials with large magnetic force should be selected to meet the normal working requirements. Under the same material, the magnetic forces of axial, radial, and radiative magnetization modes are compared. the ratio of magnetic force under axial, radiative, and radial magnetization is about 2.3:1.1:1. If NeFeB35 and SmCo28 materials are axially magnetized, their magnetic forces will exceed the allowable range, which will increase the seal wear. The increase in the inner diameter of the dynamic ring and the gap between the dynamic ring and the magnetic static ring causes a decrease in the magnetic force. The increase in temperature affects the magnetic properties of permanent magnetic material, which leads to the decline of magnetic force between the dynamic ring and the magnetic static ring. The increase in rotor speed leads to the acceleration of the fluctuation frequency of the magnetic force. Still, the maximum and minimum values of the magnetic force under different speeds remain unchanged, and the maximum fluctuation rate is less than 3%. According to the analysis results, the fitting formula of magnetic force calculation is presented by the orthogonal test and the least squares method.

Lubrication Characteristics of a Warhead-Type Irregular Symmetric Texture on the Stator Rubber Surfaces of Screw Pumps

A theoretical model for the micro-texture on the inner wall of the stator rubber in screw pumps was developed. The finite element analysis method was employed. The pressure and streamline distributions for warhead-type, concentric circle-type, and multilayer rectangular-type textured surfaces were calculated. The effects of textured morphology, groove depth, groove width, and other parameters on the lubrication field were systematically investigated and analyzed. A nanosecond laser was employed to process the textured rubber surface of the stator in the screw pump. Subsequently, a micro-texture friction performance test was conducted on the rubber surface of the stator in actual complex well fluids from shale oil wells. Given the results of the simulation analysis and experimental tests, the lubrication characteristics of textured rubber surfaces with varying texture morphologies, rotational speeds, and mating loads were revealed. Furthermore, it indicated that the irregular symmetric warhead-type micro-texture exhibited excellent dynamic pressure lubrication performance compared with concentric circle-type and multilayer rectangular-type textures. The irregular symmetry enhanced the dynamic pressure lubrication effect, enhanced the additional net load-bearing capacity of the oil film surface, and reduced friction. As the groove depth increased, the volume and number of vortices within the groove also increased. The fluid kinetic energy was transformed into vortex energy, leading to a reduction in wall stress on the surface of the oil film, thereby affecting its bearing capacity. Initially, the maximum pressure on the wall surface of the oil film increased and then decreased. The optimal dynamic pressure lubrication effect was achieved with a warhead-type texture size of 3 mm, a groove width of 0.2 mm, and a groove depth of 0.1 mm. Well-designed texture morphology and depth parameters significantly enhanced the oil film-bearing capacity of the stator rubber surface, improving the dynamic pressure lubrication effect, and consequently extending the service life of the stator–rotor interface in the screw pump.

Interaction mechanism of radial collinear cracks on a high-speed train brake disc

This article focuses on the problem of multiple crack damage in brake discs. Using the extended finite element analysis method, the interaction mechanism between radially collinear multiple cracks in brake discs is analyzed, and the influence of crack spacing and length ratio on the propagation behavior of multiple cracks is further investigated. The results indicate that the interaction mechanism between multiple radial collinear cracks on the brake disc is complex, not only influenced by the crack spacing and crack length ratio but also related to the location of the cracks on the brake disc. The interaction of radial collinear cracks on the brake disc is mainly concentrated in the stress field at the vicinity of the adjacent tips between the cracks and has little effect on the crack opening displacement field. When the distance between cracks is less than half the length of the crack of interest, the two collinear radial cracks have a significant mutual influence and tend to merge into a longer crack. The length ratio between cracks has a significant impact on the stress transmission path around the cracks, and increasing the length ratio accelerates the crack-to-crack coalescence.

Analysis of Fatigue Performance of Spot-Welded Steel T-Profiles Under Cyclic Torsional Loading

Steel T-profiles with the spot-welding manufacturing process are extensively used in various sectors such as construction, automotive, renewable energy, etc., due to their versatility and reliability. These profiles are exposed to various loading modes during their service life, which include axial, bending, shear, torsional, or combinations thereof. This paper investigates the fatigue performance of a spot-welded T-profile assembly subjected to torsional cyclic loading. The extended finite element method (XFEM) analysis was performed to simulate the intricate behavior of spot welds under the loading, elucidating critical areas prone to fatigue initiation and propagation especially around the spot welds. The simulation results were compared with previously obtained experimental results. Both results are consistent. The effects of various parameters, including the spot-weld diameters, the amount of torque applied, thickness of the profile parts, and the presence of base part, on the fatigue performance of the assembly were studied critically.

A new FEM-based approach on the modeling of stress-induced velocity shift of piezoelectric surface acoustic wave resonators

A novel methodology is introduced for the computation of stress-induced surface acoustic wave velocity shifts in piezoelectric resonators including quartz, lithium niobate and langasite resonators. The numerical framework has been verified through a comparative analysis of experimental and Finite Element Method (FEM) results for quartz resonators. This approach introduces the combined capabilities of COMSOL Multiphysics and MATLAB, facilitated by LiveLink, to systematically calculate all parameters contributing to the perturbation integral. The findings have a better accuracy using the LiveLink methodology in this study compared to prior approaches that rely on average stress and strain calculations in the central point of the resonator. Moreover, the utilization of LiveLink not only enhances accuracy but also establishes MATLAB as a fundamental software platform for interfacing with COMSOL Multiphysics. The proposed approach in this paper can extend to complex strain sensors or investigations into the influence of temperature and imbalanced loading effects in future research endeavors. Furthermore, the LiveLink approach introduced herein can be extended to optimize crystal orientation and identify premium wave directions, thereby contributing to the enhanced design of Surface Acoustic Wave (SAW) resonators. This innovative methodology is used to advance the understanding and application of stress-induced velocity shifts in SAW devices, presenting future developments in sensor technologies and resonator designs. © 2024 Elsevier Science. All rights reserved.

Refined finite element analysis of helical wire ropes under multi-axial dynamic loading

Due to high tensile strength, light weight, and good flexibility, the steel wire ropes with helical structures are widely used as crucial load-bearing components in various industrial sectors such as civil engineering. They are subjected to significant vibrations caused by multi-axial dynamic loading during the service period which may eventually result in premature failures. This paper presents a refined finite element analysis method for helical wire ropes under multi-axial dynamic loading. The proposed method employs multi-directional dynamic excitations extracted from the analysis of the overall engineering systems to consider actual loading conditions. Refined finite element analysis of the entire steel wire rope under multi-axial dynamic loading is carried out for the first time based on the global-local finite element model to obtain detailed mechanical responses. The critical rope segment is represented by solid elements taking into account the helical structure, inter-wire frictional contact, slippage, and material nonlinearity, among others, and non-critical segments are simulated with beam elements in the established global-local model, which can achieve good balance between computational efficiency and accuracy. The refined finite element modeling strategy is validated via three numerical examples with comparisons against the results in the literature. The proposed method is illustrated on the suspender cable used in suspension bridges. Detailed mechanical responses and their influencing factors are examined to acquire new insights into the dynamic mechanical characteristics of typical double-helical wire rope. The present work can provide an efficient tool for the assessment of in-service engineering systems containing helical wire ropes.

Fuzzy logic as a method of analysis of hot forging process of 80MnSi8-6 steel

A novel approach was proposed, based on the application of the fuzzy logic (FL) method for the fast analysis of the hot deformation process of 80MnSi8-6 steel. In the first stage, the curves developed from plastometric tests and the results of studies of the microstructure of the deformed samples were used as input data for the analysis. Input and output variables were adopted and a set of rules based on cause-and-effect relationships was defined, defining the interactions between the variables. A fast FL-controller was designed, and the correctness of its operation was verified by comparison with experimental results and the results of finite element method (FEM) analysis, carried out taking into account the evolution of the microstructure. The process of hot compression under isothermal conditions of 80MnSi8-6 steel specimens was simulated on the Warmumformsimulator (WUMSI), assuming such parameters and other conditions as were used in real tests. It was confirmed that the proposed method, based on the analysis of flow curves and prior austenite grain size using a fuzzy controller, gave satisfactory results. Subsequently, a novel FL-controller was developed to analyze the kinetics of dynamic recrystallization (DRX), using data obtained from the author’s model of this phenomenon for its construction and calibration. The correctness of the controller was confirmed by comparing the results of its DRX volume fraction calculations with the distributions of this value determined by the model and the model-based FEM analysis method, respectively. It was shown that FL is applicable also when a model of the analyzed phenomenon is available. Unlike model-based calculations, a properly designed controller allows the indication of deviations from general trends that can be pointed out and interpreted by a human expert, but significantly faster. It can also serve as a component of a system analyzing complex processes, such as hot multi-stage forging. Fuzzy controller can be used in parallel with modeling or replace models in calculations.

The mixed displacement method to avoid shear locking in problems in elasticity

AbstractThe mixed displacement (MD) method was initially developed to mitigate geometrical locking effects in beams, plates, and shells with the intention of having intrinsically locking‐free characteristics while using equal‐order interpolation for all degrees of freedom. In other words, it is an unlocking scheme that works independent of the element shape, polynomial order, and discretization scheme. It includes additional degrees of freedom that adhere to a carefully designed differential relation that can be interpreted as a kinematic law, incorporated in a mixed sense. Certain constraints are to be enforced on these additional degrees of freedom to obtain a well‐posed system of equations. In this work, the MD method is extended for problems in solid mechanics. We present the underlying variational formulation, followed by its application to 2D solid elements. Additionally, we showcase an idea to enforce the additional constraints in a general sense. Various numerical examples, within the framework of the finite element method and isogeometric analysis, are outlined to demonstrate the performance of the MD method in the geometrically linear and geometrically nonlinear cases.

Analysis of bearing capacity of consolidated clay under the track load of deep-sea mining vehicle

Analysis of bearing capacity of seabed consolidation foundation is conducted. Two types of bearing capacity along the vertical and horizontal directions are derived. The stress distribution between tooth plates is analyzed using the slip line field theory, and the soil between the tooth plates is divided into wedge-shaped rigid zones, passive slip zones, and transition zones. The analysis results show that the ratio of tooth depth to tooth spacing significantly affects the formation pattern of the failure zone between the tooth plates. When the depth-to-spacing ratio is small, all three zones are present, while as the ratio gradually increases, the rigid wedge-shaped zone also increases, the transition zone becomes smaller, and the passive zone disappears. Therefore, it is advisable to arrange a smaller depth-to-spacing ratio to fully exploit the strength potential of the soil between the tooth plates. The results of the finite element method (FEM) analysis also show the existence of active and passive zones beneath the crawler tracks, and due to the combination of orthogonal loadings in the vertical and horizontal directions, there is a phenomenon of skewed stress bubbles in the foundation soil beneath and correctness of the derived bearing capacity of the foundation in this study.

A DIC-FEM hybrid method for measuring strains near fiber-matrix interface of CFRP cross section

A DIC-FEM hybrid method is proposed to capture micro-scale deformation behavior near the fiber-matrix interface by combining displacement distributions measured using digital image correlation (DIC) with finite element method (FEM) analysis. Images of CFRP cross section with fine random pattern before and after deformation are taken with a laser microscope. The in-plane displacement components near the interface of fiber and matrix are obtained using digital image correlation and they are used as the input of the hybrid method. Not only the displacement distributions but the strain fields are determined using the proposed hybrid method, based on the superposition principle, so that the same distributions are obtained as those obtained by the measurement. The proposed DIC-FEM hybrid provides the strains near the interface between fiber and matrix, compensating for the insufficient resolution of microscope images.

A comprehensive finite element framework for modeling of PEX-Al-PEX composite pipes

While PEX-Al-PEX composite pipes are widely used in various applications, suitable tools and models for simulating their performance under different working conditions have not been made available. Therefore, the present study aims to develop a comprehensive finite element model to study the behavior of PEX-AL-PEX pipes at different temperatures and strain-rates. To achieve this, the properties of the pipe layers have been obtained for different temperature and strain-rate values through experimental tests. To assess the accuracy of the developed finite element model, the lateral compression and the split-disc tension tests have been performed under different conditions using both experimental and finite element analysis methods, and their results have been compared. The proposed model can be used to study the behavior of PEX-AL-PEX pipes with different materials and geometries in various conditions and applications, as well as for optimizing the design and manufacturing of these pipes.