Commercial Software Package ABAQUS Research Articles

Finite element tyre model for antilock braking system study

In the present work a 235/75R15 tyre 3D finite element (FE) model was developed using the commercial software package ABAQUS. The finite element model considers the severe nonlinearities due to a tyre's complicated geometry, hyperelastic properties of the rubber material, contact between the tyre and the road, and the reinforcing bars inside the tyre's structure. The FE model was utilised to implement a braking event of antilock braking system (ABS) controller logic. The ABS controller was developed based on a commercially available system and the logic was coded in Fortran 77 and implemented in a UVAMP ABAQUS subroutine. The detailed 3D tyre model and the FE ABS model are discussed in detail. The results show that the ABS logic is capable of maintaining the minimum slip ratio to avoid tyre sliding.

Inelastic Material Models for Numerical Analysis of Unreinforced Compressed Masonry Columns

This paper deals with numerical analysis of unreinforced compressed masonry column. The experimental program is part of a research project NAKI [1]. Three material models usually used for simulation rock, soil, concrete and other quasi-brittle materials were assumed for numerical modelling of masonry column and mutually compared. The material characteristics were identified based on literature research since the needed mechanical properties were not available. The determination of own material characteristics and comparison numerical simulation with experimental test can be outlined as a future goals. For all simulations the commercial software package ABAQUS was used and the obtained numerical results are discussed.

GS0413 Numerical study of influencing parameters of single crystal iron static recrystallization

To serve the purpose of controlling the microstructure of metal materials, it is critical to build a quantitative model to predict static recrystallization behavior. The first step to develop this model would be to relate cold working conditions to the remained stress and strain in a specimen. In order to visualize stress and strain distributions in single crystal iron specimens after tensile tests, crystal plasticity finite element method(CP-FEM) which takes crystalline anisotropy into account is incorporated in the UMAT user subroutine of the commercial software package ABAQUS. To estimate the parameters in CP-FEM, single crystal iron tensile tests with various crystal orientations are conducted and strain-stress curves are derived based on the digital image correlation toolbox NCORR. Based on abundant experimental, parameters in CP-FEM are determined and good agreement with the experiments is derived.

Local–Global Interaction Buckling of Stainless Steel I-Beams. II: Numerical Study and Design

The paper presents a detailed finite-element model used to study the local–global interaction buckling of stainless steel I-section beams. The model was constructed with the commercial software package ABAQUS v.6.11 and was verified against the experimental data presented in a companion paper, yielding accurate predictions of interaction buckling behavior and ultimate capacity. Parametric studies were conducted by using the calibrated models to extend the experimental database. The accuracy of the Australia/New Zealand, American, and European standards for stainless steel structures was evaluated by using the available data. It was found that the codes were incapable of capturing the interaction buckling effect, thus affording overly optimistic strength predictions for beams of high section slenderness. Existing direct strength method formulas, as proposed for carbon steel beams and stainless steel columns, were also evaluated to assess their applicability to the stainless steel beams.

A finite element implementation of a coupled diffusion-deformation theory for elastomeric gels

The theory of Chester and Anand (2011) for fluid diffusion and large deformations of elastomeric gels is implemented as a user-defined element (UEL) subroutine in the commercial finite element software package ABAQUS. A specialized form of the constitutive equations and the governing partial differential equations of the theory are summarized, and the numerical implementation is described in detail. To demonstrate the robustness of the numerical implementation a few illustrative numerical simulation examples for axisymmetric, plane strain, and three-dimensional geometries are shown. For educational purposes, and also to facilitate the numerical implementation of other coupled multiphysics theories, the source code for the UEL is provided as an online supplement to this paper.

A semi-concurrent multiscale approach for modeling damage in nanocomposites

The paper presents an effective implementation of a semi-concurrent multiscale method in the commercial finite element software package ABAQUS. The method is applied to the pre-localized damage initiation and propagation in the fully exfoliated clay/epoxy nanocomposite. The obtained results of the proposed method is also compared with the hierarchical multiscale approach. This method can be easily used to get a better understanding of damage mechanism in the nanocomposite materials in order to improve the constitutive models and to support the future design of those materials.

Thermal Analysis on Butt Welded Aluminium Alloy AA7075 Plate Using FEM

Thermo-mechanical finite element analysis has been performed to assess the residual stress in the butt weld joints of aluminium Alloy AA7075 plates by utilizing the commercial software package ABAQUS. This paper presents an efficient FE technique using equivalent load to precisely predict welding deformations and residual stresses in butt joints. The radial heat flux distribution is considered on the top surface of the weldment. Convective and radiative heat losses are taken into account through boundary conditions for the outward heat flux. Linear FE transient thermal analysis is performed using surface heat source model with Gaussian distribution to compute highest temperature in AA7075 plates. The objective of this project is to simulate the welding process by using the finite element method. After the model is built and verified, the main objective of this project is to study the effects of varying the welding process parameters on the thermo-mechanical responses. In addition to that, the aim of this research is also to find a relationship between welding parameters and the responses of single pass butt welding are evaluated through the finite element analysis. The study of this paper covers the effects of varying heat input, welding speed on the thermo-mechanical responses of the weldment after cooling down to room temperature.

Finite Element Modeling of Existing Cracks on Pre-loaded Reinforced Concrete Beams

The finite element modeling approach for verifying the load deflection behavior of damaged reinforced concrete beams strengthened with fiber-reinforced composites is presented in this study. The existence of cracks in the damaged reinforced concrete beams was included in the model as geometrical entities. Parametric studies were carried out and the adequate values for crack width, height and interval were proposed for different damage levels. Concrete damaged plasticity and traction separation model were employed to model the behavior of concrete and epoxy, respectively. A commercial finite element software package ABAQUS was employed for a numerical analysis and all modeling steps were verified with published experimental data. Comparisons between numerical and experimental results confirm that proposed crack modeling was appropriate for obtaining the load–deformation curve of the initially damaged reinforced concrete beams strengthened with fiber reinforced composites.

Investigation on the Residual Stress State of Drawn Tubes by Numerical Simulation and Neutron Diffraction Analysis.

Cold drawing is widely applied in the industrial production of seamless tubes, employed for various mechanical applications. During pre-processing, deviations in tools and their adjustment lead to inhomogeneities in the geometry of the tubes and cause a gradient in residuals. In this paper a three dimensional finite element (3D-FE)-model is presented which was developed to calculate the change in wall thickness, eccentricity, ovality and residual macro-stress state of the tubes, produced by cold drawing. The model simulates the drawing process of tubes, drawn with and without a plug. For finite element modelling, the commercial software package Abaqus was used. To validate the model, neutron strain imaging measurements were performed on the strain imaging instrument SALSA at the Institute Laue Langevin (ILL, Grenoble, France) on a series of SF-copper tubes, drawn under controlled laboratory conditions, varying the drawing angle and the plug geometry. It can be stated that there is sufficient agreement between the finite element method (FEM)-calculation and the neutron stress determination.

LOCALIZED ELECTROCHEMICAL CHARACTERIZATION OF HIGH STRENGTH ALUMINIUM ALLOY AT THE CRACK TIP IN 3.5%NaCl SOLUTION

The electrochemical microcapillary technique and scanning Kelvin probe(SKP) were applied to study the localized electrochemical characterization and corrosion behavior at the crack tip of 2024-T351 aluminium alloy in 3.5%NaCl.To investigate the effect of stress on the localized corrosion process at the crack tip,numerical simulation of the stress distribution on a pre-cracked wedge-open loading(WOL) specimen was conducted using a commercial software package ABAQUS 6.10.Polarization curves revealed that corrosion potential at the crack tip was more negative than that within the region away from the crack tip.Localized electrochemical impedance spectroscope(EIS) showed that the passive film was thinner at the crack tip than within the region away from the crack tip.The results indicate that the crack tip is more electrochemically active than the region away from the crack tip.Furthermore,passive film at the crack tip was less stable than that on other region of the specimen surface.SKP measurements demonstrated that there was a non-uniform distribution of Volta potential on the pre-cracked WOL specimen surface,with a more positive Volta potential occurring at the crack tip after 24 h immersion into 3.5%NaCl solution.This might be explained by the preferential anodic dissolution and the accumulation of the corrosion product at the crack tip. Numerical simulation results showed that a very high local stress concentration was developed at the crack tip,which could enhance the electrochemical activity around the crack tip and promote the dissolution process therein.Moreover,a galvanic couple could also occur between the crack tip acting as the anode and the distant region as the cathode,which results from the differences of the corrosion potentials and the electrochemical activities between them.As a result,the anodic dissolution of 2024-T351 aluminium alloy at the crack tip is enhanced.

Experimental and numerical investigations of the compressive behavior of concrete filled steel tubes (CFSTs)

This paper presents an experimental study to investigate the compressive behavior of circular concrete filled steel tubes (CFSTs) when subjected to pure axial loading at a low rate of 0.6kN/s. CFSTs of three different diameter-to-thickness (Dt) ratios of 54, 32, and 20 are considered in this study filled with two concrete's compressive strengths of 44MPa and 60MPa. The measured compressive axial capacities are compared to their corresponding theoretical values predicted by four different international codes and standards: the American Institute of Steel Construction (AISC), the American Concrete Institute (ACI 318), the Australian Standard (AS), and Eurocode 4. Result comparisons also included some suggested equations found in the literature. It was found that the effect of (Dt) ratio on the compressive behavior of the CFST specimens is greater than the effect of the other factors. The underestimation of the axial capacities calculated by most of these codes reduces as the Dt ratio increases as verified by the experimental results. A nonlinear finite element (FE) numerical model using the commercial software package ABAQUS is also developed and verified using the presented experimental results.

Finite element simulation of projectile perforation through a ballistic fabric

A finite element (FE) model is developed to simulate the ballistic impact of a flat-faced cylindrical projectile onto a flexible plain woven fabric made from Kevlar. The geometric model of the fabric was made by an in-house CAD programme known as UniverWeave© on the specification of actual structural parameters of a fabric. Commercial software package ABAQUS was used to simulate the projectile–fabric impact process assuming that the constituent yarns are elastic and plastic when loaded. Comparison between the experimental and the simulated results revealed that the developed model for projectile–fabric impact using ABAQUS/Explicit is effective to simulate the ballistic impact process with high accuracy. The dynamic mechanisms of the impacted fabric were studied. It showed that the projectile lost its velocity quickly at the beginning and then decreased slowly. The cone formed in the backface of the impacted fabric is virtually linear with respect to time. The cone radius increased rapidly at the very beginning of the impact and less significant afterwards. A smaller cone base radius was found to correspond to a higher velocity impacted fabric. It also has been found that the main forms of energy absorption are the kinetic energy of the cone, the plastic and elastic energy of the impacted fabric. Furthermore, it is believed that a specified fabric can be designed and engineered against a certain level of threat based on the finding that there exist a specific impact energy under which the fabric absorbs maximum projectile impact energy.

Thermo-mechanical modeling of dendrite deformation in continuous casting of steel

In the field of modern steelmaking, continuous casting has become the major manufacturing process to handle a wide range of steel grades. An important criterion characterizing the quality of semi-finished cast products is the macrosegregation forming at the centre of these products during solidification. The deformation induced interdendritic melt flow has been identified as the key mechanism for the formation of centreline segregation. Bulging of the solidified strand shell causes deformation of the solidifying dendrites at the casting's centre. Hence, a fundamental knowledge about the solid phase motion during casting processes is crucial to examine segregation phenomena in detail. To investigate dendritic deformation particularly at the strand centre, a thermo-mechanical Finite Element (FE) simulation model is built in the commercial software package ABAQUS. The complex dendritic shape is approximated with a conical model geometry. Varying this geometry allows considering the influence of different centreline solid fractions on the dendrite deformation. A sinusoidal load profile is used to describe bulging of the solid which deforms the dendrites. Based on the strain rates obtained in the FE simulations the dendrite deformation velocity perpendicular to the casting direction is calculated. The velocity presented for different conditions is used as input parameter for computational fluid dynamics (CFD) simulations to investigate macrosegregation formation inside of a continuous casting strand using the commercial software package FLUENT.

Modeling of Temperature-Sensitive Polyelectrolyte Gels by the Use of the Coupled Chemo-Electro-Mechanical Formulation

Polyelectrolyte gels show adaptive viscoelastic characteristics. In water-based solutions they have enormous swelling capabilities under the influence of different possible stimulation types, such as chemical, electrical, or thermal stimulation. Possible applications for these intelligent materials can be either actuators, e.g., when used as artificial muscles or chemo-electric energy converters, or sensors, e.g., for measuring ion concentrations or pH-values of the solutions. In order to represent this active behavior, a coupled multi-field model is applied. The chemo-electro-mechanical multi-field formulation considers changes of concentrations, electric potential, or strains due to varying (initial) conditions. In the present work, a fully coupled 3-field formulation for polyelectrolyte gels using the Finite Element Method is applied. This formulation consists of a chemical, electrical, and mechanical field equation. The chemical field is described by a partial differential equation (PDE) first order in time and second order in space and includes diffusional, migrational, and convectional effects. The electrical field is represented by the Poisson equation, an elliptical PDE of second order in space. Finally, the mechanical field is described by a PDE of first order derived from the conservation of momentum. Due to the slow processes in time, inertia terms are neglected. The mechanical field is coupled to the chemo-electrical field by a prescribed strain stemming from an osmotic pressure term. A large dependency between the applied temperature and the actual swelling degree of the gel has been proven in experiments. In the present research, the thermal stimulation is investigated using two alternative approaches: The first is a straight forward modeling by modifying the actual temperature in the osmotic pressure term. As this approach does not lead to promising results, as a second alternative temperature-dependent material parameters obtained from experimental measurements are applied. The calibration of the derived simulation results is performed with experimental results from the literature. The Finite Elements introduced for the coupled multi-field formulation contain degrees of freedom for concentrations, electric potential, and mechanical displacements. They are adopted and applied in the commercial software package ABAQUS as a user defined element. For the numerical solution, the Newton-Raphson method in conjunction with the implicit backward Euler time integration scheme is applied.

Numerical Investigation of Stress Distribution during Die Compaction of Food Powders

A numerical method is presented to determine the internal stress distribution in powder compacts during uniaxial die compaction using the finite element method. A continuum-based analysis was carried out considering the powder body forming a tablet as an elastic-plastic continuum. Compaction behavior and mechanical material properties were defined using a modified density-dependent Drucker-Prager cap (DPC) material model. In addition, a nonlinear elasticity law was adopted to describe the nonlinear unloading behavior observed for the tested amorphous and crystalline food powders. The constitutive model was calibrated using an experimental procedure based on uniaxial die compaction experiments. All material-dependent parameters were determined experimentally using a fully instrumented hydraulic tablet press with a single-ended compaction profile. Numerical simulations of the compaction process were carried out by the commercial finite element software package ABAQUS using the calibrated material model and experimental friction data. The simulation results were in good agreement with experimental data, which demonstrated the suitability of this method to investigate internal processes during tableting.

Fracture mechanics of spot-welded steel sheets of equal thickness in Coach-peel specimens

In the current paper, a numerical investigation based on the finite element method was constructed to analyse fracture mechanics of two L-shaped sheets welded with resistance welding. The fracture behaviour of the welded structure is considered with the assumption of a crack at the interface of the welded sheets. The study was treated as a linear elastic fracture mechanics problem in mixed mode, under plane stress conditions. Computations were performed using the commercial FE software package ABAQUS. The modelling results highlight the dependence of the stress intensity factors on key design parameters of spot welds such as nugget diameter, bent curvatures, sheet thickness, material properties and the applied load.

A 3D active-passive numerical skeletal muscle model incorporating initial tissue strains. Validation with experimental results on rat tibialis anterior muscle

This paper presents a three-dimensional finite element model of skeletal muscle and its validation incorporating inital tissue strains. A constitutive relation was determined by using a convex free strain energy function (SEF) where active and passive response contributions were obtained fitting experimental data from the rat tibialis anterior (TA) muscle. The passive and active finite strains response was modelled within the framework of continuum mechanics by a quasi-incompressible transversely isotropic material formulation. Magnetic resonance images (MRI) were obtained to reconstruct the external geometry of the TA. This geometry includes initial strains also taken into account in the numerical model. The numerical results show excellent agreement with the experimental results when comparing reaction force-extension curves both in passive and active tests. The proposed constitutive model for the muscle is implemented in a subroutine in the commercial finite element software package ABAQUS.

Investigation of die radius arc profile on wear behaviour in sheet metal processing of advanced high strength steels

Advanced high strength steels (AHSS) are increasingly used in sheet metal stamping in the automotive industry. In comparison with conventional steels, AHSS stampings produce higher contact pressures at the interface between draw die and sheet metal blank, resulting in more severe wear conditions, particularly at the draw die radius. Developing the ability to accurately predict and reduce the potential tool wear during the tool design stage is vital for shortening lead times and reducing production cost. This paper investigates the effects of draw die geometry on the sheet metal tool wear distribution over the draw die radius using numerical and experimental methods. A numerical tool wear model is introduced and applied using the commercial software package Abaqus. Channel bend tests are carried out using an Erichsen sheet metal tester to verify the numerical model. Various geometries of radius arc profiles, including standard circular profiles, high elliptical profiles, and flat elliptical profiles, are numerically investigated, and the wear volume and contact pressure distribution along the radii are determined. The results show that the profile of the draw die radius has a significant effect on the wear distribution, and that a low contact pressure distribution can be achieved by using a combination of circular and high elliptical curved geometries.

A Finite Element Analysis for the Characteristics of Cutting Parameters in 3D Oblique Milling Process

In the field of aeronautical and astronautical manufacturing, milling is a basic machining process by which a surface is generated by progressive chip removal. Therefore, this paper reports a complete procedure of the finite element model for the 3D oblique milling process using the commercial software package ABAQUS. Effect of various parameters on cutting forces is mainly discussed. The model correctly exhibits the observed transition from small to large force with increasing cutting speed and cutting depth.

A study on the estimation of SWIFT model parameters by finite element analysis

The SWIFT model is an extension of the MF-Tyre model developed by TNO and Delft University of Technology. This model, applicable up to 60Hz longitudinal frequency, considers envelopment characteristics of the tyre. This paper presents the finite element analysis (FEA) approach to arrive at the 172 SWIFT model parameters. A 235/75R15 tyre is modelled using the commercial software package ABAQUS. The mixed Lagrangian—Eulerian approach has been used to simulate the loaded radius and contact length. Envelopment and cleat simulations are done with an explicit solver. The data curve fitted with MF Tool are found to be reasonable. This technique can be used to obtain SWIFT model parameters so that the vehicle dynamic behaviour of the tyre—vehicle combination can be virtually assessed before a real tyre is built; this will significantly reduce the tyre development time.