ANSYS Finite Element Model Research Articles

Exploring key factors affecting the ultimate compression capacity of Unbonded Steel-mesh-reinforced Rubber Bearings

To address bearing-sliding damage in highway bridges during seismic events, the Unbonded Steel-mesh-reinforced Rubber Bearing (USRB) was developed. This novel bearing employs flexible, high-strength steel wire meshes as reinforcement, enhancing lateral deformation capacity and reducing bearing-sliding risk. Recent seismic specifications increased the bearings' vertical design load to 30 MPa, where existing bearings with flexible reinforcements (e.g., fiber-reinforced bearings) fail to meet this standard. Hence, for the first time, our study thoroughly investigated the ultimate compression capacity of USRBs and the key factors influencing the capacity. Through ultimate compression tests on full-scale prototypes, we demonstrated that USRBs can comply with heightened seismic requirements, with primary failure attributed to the tensile failure of the steel mesh reinforcement. These tests were complemented by 3D finite element modeling in ANSYS, employing the LINK180 elements for mesh reinforcement and defining the ultimate capacity as the point at which reinforcement stress reached tensile strength. This particular modeling approach, validated against experimental data, can accurately predict the ultimate compression capacity and the force-deformation response of USRBs. A comprehensive parametric analysis, using the validated modeling approach and an advanced statistical method LHS-PRCC, was conducted to identify the key factors influencing the compressive capacity, including bearing geometric parameters (i.e., bearing width, the second shape factor, and rubber layer thickness), steel-mesh configuration characteristics, and steel-mesh material properties. Our findings emphasize the significance of rubber layer thickness, steel mesh weight, and steel wire tensile strength and strain in influencing the USRBs' ultimate compression capacity. Based on these key factors, an empirical equation for the ultimate compression capacity of USRBs was established to guide the optimization design of USRBs. This study not only fills the gap in USRB's performance under extensive compression but also provides a foundation for future optimization of these bearings to enhance their performance in bridge engineering.

Fatigue life assessment of high-speed train’s bogie frame due to dynamic loads under the influence of wheel flat

A bogie frame is the most important railway vehicle’s component that supports almost the weight of the system, and it is subjected to various excitations and loads that can result in the failure of the structure. The dynamic forces influenced by various excitations, both internal and external, can speed up the system's fatigue failure. This paper aims to analyse the impact of wheel flats on the life of a high-speed bogie frame. To accomplish this study, a Chinese railway high-speed (CRH2) bogie frame, has been chosen for the analysis. The required input data for CRH2 have been collected from literature; the wheel flat defect models under the wheel flat lengths of 20 mm, 40 mm, and 60 mm have been developed with a MATLAB tool, and the results have been inputted into a multibody model with the SIMPACK tool. The dynamic response loads for each case have been exported and applied to the finite element model in ANSYS, where stresses and strain have been used to estimate the fatigue life. The results from the study show that as the wheel flat length increases, it increases the dynamic forces and stresses that decrease the life of the bogie frame; thus, the influence of wheel flat should be considered in the life prediction of a bogie frame.

Finite Element Analysis of Laminated Composite Shells with Piezoelectric Elements

The concept of incorporating some degree of smartness or intelligence in a system is gaining wide acceptance for utilisation in a variety of practical applications from aircraft to medical diagnostics because of the capability of smart materials to execute specific functions intelligently in response to changes in environmental stimuli. In this paper, the effectiveness of a simple finite element model in ANSYS is established for analyzing laminated composite shells with piezoelectric elements under static and dynamic loading. The substrate in smart shell is discretised using SOLSH190 element and the piezoelectric layer is discretised using coupledfield element, SOLID5. The basic behaviour of a smart composite shell depends on the behaviour of substrate with the response reduced/controlled by the properties of smart materials used, which is predicted effectively by the present finite element model.

Multi-level Reliability-Based Design Optimization (RBDO) study for electronic cooling: Application of heat sink based on multiple phase change materials enhanced with carbon nanoparticles

Phase change materials represent efficient performances in the thermal management field. However, the low thermal conductivity poses a serious restraint for electronic cooling applications. Recently, the use of multiple phase change materials and the dispersion of nanoparticles are the most recommended techniques to improve the performance of the heat sink. In this study, a developed heat sink filled with multiple phase change materials (PCMs) enhanced with carbon nanoparticles was proposed. First, a parametric study was carried out to determine the optimal pair of phase change materials and nanoparticles. Then, deterministic design optimization and various reliability-based design optimization methods are performed. The optimization and reliability problems are solved by coupling the MATLAB optimization toolbox and the ANSYS Finite Element Model. The optimization-reliability results prove the efficiency of the Robust Hybrid Method in proposing a reliable and optimal heat sink design filled with multiple nano-enhanced phase change materials. The temperature is reduced by 25 % (16,5 °C) and the discharge time is reduced by 8,69 % (14 min) compared to the baseline heat sink.

Validation of Rayleigh-Ritz Deflection Equation for a Tapered Cantilever Beam using ANSYS Finite Element Software

Models are like our eyes and ears as they provide the basis for making very important design decisions in engineering. They give predictions that help engineers to foretell or foresee a system’s behaviour in real life. Validation ensures that these models give proper or accurate representation of the real system. In this study, a model equation derived for predicting the end deflection of a tapered width, constant height cantilever beam was adopted for validation. This equation was derived using the Finite Element Method's Rayleigh-Ritz principle and the virtual work concept. Using a finite element model developed in ANSYS as the representation of the real system and a basis for validation, this study aimed to validate the equation. Validation was achieved by the comparison of the load-deflection curve, the height-deflection curve and the end deflection of the model equation to that of the finite element model in ANSYS. Though the model equation was verified to really foretell deflection, the predictions of the equation was not in good agreement with that of the finite element model. The accuracy of the equation dwindled as the parameters of the tapered cantilever beam were varied. It gave an average percentage error of 30% higher than the allowable error of 5%. Though the equation was derived using the appropriate fundamental numerical principles as it basis, it’s accuracy can be exponentially increased by modifying it to include a larger number of discretized elements and a higher degree of shape/interpolation function.

Static analysis of box-girder bridge under the influence of Indian railway vehicle loading using ANSYS finite element model

The box-girder bridge has recently gained a lot of popularity because of its serviceability, stability, and structural efficiency. The box-girder bridge also has a lower structural weight than any other type of bridge. However, the analysis of such a bridge is too complex and challenging for the designers. This paper offers a modelling process for the study of a box- girder bridge with a ballastless sub-track system using the finite element method and evaluates the different static response characteristics of the bridge when it is loaded according to Indian Railway standards. The modelling and the evaluation of the 3D model of the bridge have been done using non-closed form finite element method (FEM) based ANSYS software and loadings have been applied symmetrically and un- symmetrically. Static analysis is carried out. The model has been simulated, and the resultants of deflection and stresses have been determined, taking into account the effect of different combinations of loading from the Indian Railways. The present modelling process is applied to analyze the box-girder bridge for 5 spans of 32 m each. For analysis of any box-girder bridge, though, researchers can use the modelling process described above.

Investigating the Effect of Cutting Speed on Heat Affected Zone in Laser Cutting Process of Stainless Steel

This research work investigated the effect of cutting speed, laser power and nozzle diameter on heat affected zone as well as surface roughness in laser cutting process of stainless steel. The practical experiment was carried out using laser cutting machine, while ANSYS finite element modeling (FEM) simulation software was employed in analyzing the responses of the laser beam machining parameters on stainless steel (SS316). The result showed that an inverse relationship exists between the cutting speed of the laser cutting machine and the heat affected zone (HAZ) depth as increasing the laser beam cutting speed consequently reduced the heat affected zone (HAZ) depth in the work-piece. Finally, it can be concluded that using appropriate machining parameters and ANSYS FEM technique could yield a reduction in overall machining costs and saves time for production companies through an economic analysis by applying the technique to predict the optimal machining parameters for their steel products.

Block–Wheel–Rail Temperature Assessments Via Longitudinal Train Dynamics Simulations

Abstract Two research gaps were identified in block–wheel–rail temperature assessment. First, current studies are not combined with train dynamics, which are better descriptions of the block–wheel–rail working environment. Second, current studies cannot simulate long rail sections. This paper developed a block–wheel–rail temperature assessment model by following the finite element idea. Models were validated by comparing with ansys Finite Element models and measured data. Case studies were carried out by combining the temperature model with a Longitudinal Train Dynamics model. A full-service and an emergency brake simulation were carried out for a 150-wagon heavy haul train on a 5680 m long rail section. The results show that, due to brake force differences at different wagon positions, the maximum block and wheel temperature differences among individual wagons in the full-service brake simulation were 117.01 °C and 117.91 °C, respectively. This highlighted the contribution of introducing train dynamics into block–wheel–rail temperature assessment. Rail temperature increases caused by wheel–rail temperature differences and frictional heating were about 10.60 °C and 2.65 °C, respectively.

An Analytical Solution for the Geometry of High-Speed Railway CRTS Ⅲ Slab Ballastless Track

To study the mapping relationship between girder deformation and rail deformation for the CRTS Ⅲ slab ballastless track (SBT) multi-span simply supported bridge, this study derived a simplified analytical solution, and the corresponding ANSYS finite element model (AFEM) was established. Compared with the fine analytical model (FAM) and the AFEM, the calculation results of the three models under the conditions of pier settlement and girder vertical fault were compared, which verified the universal properties of the simplified analytical model (SAM). Based on the verified SAM, the influence of pier settlement, fastener stiffness, girder span, and girder vertical fault on rail deformation was studied. The results show that the rail deformation is approximately proportional to pier settlement and girder vertical fault. With the increase in fastener stiffness, the fastener internal force increases, the rail mapping deformation increases, and the length of the rail mapping deformation area decreases. With the increase in girder span, the rail deformation curve becomes smooth, the length of the rail mapping deformation area becomes longer, and the fastener internal force is significantly reduced.

Energy harvesting using an acoustic metamaterial

Acoustic energy is harvested using a piezoelectric-based metamaterial. The considered metamaterial harvester consists of a multi-cell array of acoustic cavities, which are provided with piezoelectric boundaries in a one-dimensional arrangement. Once impacted by an incident parasitic acoustical energy, these boundaries convert this acoustical energy into useful electrical energy. An ANSYS finite element model is developed to model the dynamics of the multi-field energy harvesting, predict the harnessed power, and optimize the performance of the piezoelectric-based metamaterial when coupled with an external load. The predictions of the ANSYS model are validated against the predictions of a lumped-parameter model of the harvester, which is based on the equivalent electrical analog of the harvester. Excellent agreement is observed between the predictions of ANSYS and the lumped-parameter models. The predictions of the models are validated experimentally using a prototype of the harvester consisting of five cells each of which is manufactured from acrylic cylinders provided with piezoelectric bimorphs This arrangement enables harnessing the energy by the two sides of the bimorph in order to maximize the extracted power of the harvester. The frequency characteristics of the output power of the harvester are determined in relation to the bandgap characteristics of the periodically structured metamaterial. The presented work lays down the foundation for two and three-dimensional metamaterial energy harvesters.

Study on the influence of restraint stiffness of main material on the compression stability bearing capacity of cross-bracing in transmission tower

Abstract In order to study the influence of restraint stiffness of main material on the compression stability bearing capacity of cross-bracing in transmission tower, in this paper, the load of cross-bracing under eccentric compression in transmission tower is simulated. The load test of 45 Q355 equilateral angle steel cross-bracing specimens with typical sections is completed, and an effective ANSYS finite element model is established for analysis. The effects of the restraint stiffness of main materials, slenderness ratio, material strength and the number of connecting bolts on the bearing capacity of cross-bracing are discussed, and the relevant laws are obtained, which provides a reference for engineering application.

Analysis of frequency response sensor of MEMS gyroscope in vacuum chamber

This article presents a study of the frequency response of a MEMS gyroscope in a vacuum chamber. On the basis of experimental studies by the method of laser Doppler vibrometry, the dependences of the amplitude of oscillations of the inertial mass in the vertical plane at various pressures are obtained. The bandwidth of the MEMS sensor was also measured.As a result of the experiments, the damping factors were determined to compose a more complete mathematical model and for more accurate finite element modeling in ANSYS, and refined parameters of the electrostatic drive and the amplitude of oscillations along the axis of the drive were obtained. These studies will be useful for determining the residual degree of vacuum in the case for further frequency tuning of the device.

Vibration Analysis of the Third Rail Structure of a Mass Rapid Transit System with Structural Defects

The third rail is a critical piece of railway infrastructure that provides a continuous supply of electricity to power mass rapid transit trains. The vibration of the third rail may excite different resonant modes and affect its structural integrity and reliability by degrading the mechanical properties leading to the damaged or missing structural components. This paper examines vibrational characteristics of the third rail of Singapore Mass Rapid Transit system with damaged and missing structural components. Using the mathematical model, the first five, pin-to-pin modes of vibration and natural frequencies were identified and compared with modal and harmonic response obtained from ANSYS finite element models. A good agreement was observed between the analytical and numerical solutions. The study was further extended to study the sagging of the third rail due to structural failure and its impact on collector shoes. It was found that the structural defects could produce resonance modes below 5 Hz. In addition, the sagging and contact force on collector shoes increased by multiple folds when more than 2 claw structures are broken. The methods and the results presented in this article can be used as a tool for predictive maintenance by detecting possible structural failure or defects.

Modeling Mechanical Properties of Multilayer Coatings TiAlN

The paper outlines two approaches (the ANSYS finite element modeling and the differential scheme of the self-consistency method) to model the mechanical properties of TiAlN multilayer coatings. To validate the experimental results, these findings were compared with the nanoindentation test results for single and multilayer coatings. This work has revealed the effect of Ti/Al ratio on the mechanical properties of multilayer coatings. The given approaches could be applied to calculate, with an acceptable margin of error, the mechanical properties of TiAlN multilayer coatings.

Energy Absorption and Mechanical Performance of Functionally Graded Soft-Hard Lattice Structures.

Today, the rational combination of materials and design has enabled the development of bio-inspired lattice structures with unprecedented properties to mimic biological features. The present study aims to investigate the mechanical performance and energy absorption capacity of such sophisticated hybrid soft–hard structures with gradient lattices. The structures are designed based on the diversity of materials and graded size of the unit cells. By changing the unit cell size and arrangement, five different graded lattice structures with various relative densities made of soft and hard materials are numerically investigated. The simulations are implemented using ANSYS finite element modeling (FEM) (2020 R1, 2020, ANSYS Inc., Canonsburg, PA, USA) considering elastic-plastic and the hardening behavior of the materials and geometrical non-linearity. The numerical results are validated against experimental data on three-dimensional (3D)-printed lattices revealing the high accuracy of the FEM. Then, by combination of the dissimilar soft and hard polymeric materials in a homogenous hexagonal lattice structure, two dual-material mechanical lattice statures are designed, and their mechanical performance and energy absorption are studied. The results reveal that not only gradual changes in the unit cell size provide more energy absorption and improve mechanical performance, but also the rational combination of soft and hard materials make the lattice structure with the maximum energy absorption and stiffness, in comparison to those structures with a single material, interesting for multi-functional applications.

Effect of moisture on mechanical characteristic of soil and interaction of soil-pile in integral abutment bridges

Mechanical properties of soil are function of many parameters. Moisture content is one of the key factors that impact the soil’s mechanical properties. Soil-pile interaction and pile displacement in bridges can, therefore, be impacted by the moisture content. In particular, pile displacement in Integral Abutment Bridges (IABs) due to daily and seasonal temperature variations is a problem that has been under investigation. IABs don’t have joint and as a result all the load and deformation in the slab is transferred to piles. If piles are deformed beyond their yield point, plastic deformation can occur. The objective of this study is to evaluate the moisture content effect on the interaction of pile and soil and the resulting pile displacement through computational modeling. An ANSYS Finite Element Model (FEM) is used to repeatedly change the moisture content of the soil and adjust the properties and compute the displacement in the piles. It is shown that increasing the moisture content decreases several key parameters such as bulk density, young’s modulus, cohesion and Poisson’s ratio. The simulation results indicate higher displacements of the piles as the moisture content increases. This behavior can be explained by decreased elastic modulus. As a result, soil behaves more flexible and allows more displacement of the pile.

Numerical analysis for estimating ballistic performance of armour material

Ballistic performance of naval ship structured material is analysed by formulating numerical simulation technique using 3-D explicit dynamic nonlinear finite element model in ANSYS®19. The methodology includes the effects of plastic deformation and facture of material describing flow stress, strain and strain rate hardening parameter under terminal high velocity ballistic impact. Initially, numerical simulation was carried on Weldox700E armour plate using Johnson-Cook strength and failure criteria with NATO ball bullet as impacting projectile for validation purpose. Further, the validated model is used to simulate the impact behaviour of Al5083 structural material subjected to high velocity impact of 7.62 × 39 mm mild steel core bullet having different thickness. The former simulation result was compared with available literature while the latter is evaluated using the experimental test findings. Residual velocity of projectile, failure mode and deformation pattern of target plate, projectile displacement and energy summary were used to determine characteristics of ballistic event. The methodology used in this paper demonstrates significant efficiency and adequacy of the implemented Johnson Cook model to determine a non-linear physical penetration mechanism and its experimental measurable parameters.

The application of the Wittrick-Williams algorithm for free vibration analysis of cracked skeletal structures

In this study, the dynamic stiffness method is applied to a cracked beam that incorporates Rayleigh bar theory and Timoshenko beam theory, and the Wittrick-Williams algorithm is used to pinpoint natural frequencies. The influence of a crack on the two components of the Wittrick-Williams algorithm, namely, the number of negative leading diagonal terms in the upper triangular form of the global dynamic stiffness matrix at a trial frequency, and the sum of frequencies of each clamped-clamped element of the structure exceeded by the trial frequency, is explored. For the first component, the leading diagonal terms relevant to the additional degrees of freedom introduced by the crack should be considered. While for the second component, it is shown that a crack element itself does not contribute to the second component. The influence of a crack element on the second component only lies in that the crack alters the discretization thus more beam elements are involved. The same philosophy applies to the introduction of an affiliated mass or spring-mass system. To verify this statement, the free vibration of a cracked single-storey frame carrying a roving mass with rotary inertia is studied. The frequency results obtained using the dynamic stiffness method incorporating the Wittrick-Williams algorithm are compared with those exported from a finite element model in ANSYS. Some discussions about the results are made. The effects of roving translational inertia and roving rotary inertia are studied.

Nonlinear dynamic responses of beamlike truss based on the equivalent nonlinear beam model

The main goal of this paper is to develop an equivalent nonlinear beam model (ENBM) for forced vibration analysis of the nonlinear beamlike truss (NBT) and its numerical implementation for describing the nonlinear behaviors of the periodic NBT. For the equivalent dynamic modeling method based on the energy equivalence principle of the truss structures, most of the existing approaches focus on studying the linear characteristic which cannot satisfy the nonlinear dynamic analytical requirement. Here, we extend the equivalent dynamic modeling to nonlinear forced vibration responses of the large NBT civil engineering structure with two pinned ends. We introduce the geometric nonlinearity into the equivalent dynamic model using the von Karman nonlinear strain-displacement relationship to imitate the nonlinear behaviors of the beamlike truss. On the basis of the Hamilton principle, the fourth-order governing partial differential equations of motion of the ENBM are obtained and solved utilizing the Galerkin method. It is shown that the ENBM accurately captures the nonlinear dynamic response of the beamlike truss subjected to external load by using the first four order modes. In order to showcase the efficiency and accuracy of the ENBM, time histories, phase maps and fast Fourier transform frequency spectra are investigated for the NBT and the ENBM under different external excitation magnitudes and frequencies. Comparisons between results of the ENBM and those obtained from the finite element simulations of the NBT show good agreements and identify the periodic motions of them. Furthermore, the effect of the external loading and damping parameters on the frequency-response and force-response curves is discussed. In addition, computing time of the proposed ENBM are compared with that of the full-scale finite element model in ANSYS so as to highlight the significant less computational cost of the equivalent nonlinear dynamic modeling. Particularly, the proposed ENBM can achieve the nonlinear mechanism of the NBT in analytical method and design the low-order control law conveniently.

Effect of Insertion Viscoelastic Damping Layer with Different Thicknesses on the Dynamic Response of Multi-layered Beam in Forced Vibration

In this work, we study the effect of the thickness variation of viscoelastic layer inserted in a laminated multi-layer beam in forced vibration on the vertical displacements and on the natural frequencies. The new structure is a sandwich structure composed by two external layers (top and bottom facesheets) of aluminum and viscoelastic core of 3M ISD112 polymers. The viscoelastic model used to describe the behavior of the core is a four-parameter fractional derivative model. The finite element method including the viscoelastic model of fractional derivatives for modeling the sandwich structure is used. The system resolution of the nonlinear equations of motion of the sandwich structure is required to use a numerical integration method as the explicit method of Newmark to obtain the transient response. Also, ANSYS finite element modeling is applied to the sandwich structure to calculate the frequency response in harmonic vibration. The increase in the thickness of the viscoelastic layer leads to a decrease in the amplitudes of vibration. The natural frequencies found by the two methods are very close to the frequencies found experimentally in the literature.