A Numerical Elastoplastic Model for Rough Contact

1995 ◽  
Vol 117 (3) ◽  
pp. 422-429 ◽  
Author(s):  
C. Mayeur ◽  
P. Sainsot ◽  
L. Flamand
Keyword(s):  
Yield Criterion ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Surface Shape ◽  
Real Surface ◽  
Pressure Distributions ◽  
Surface Displacements ◽  
Elastic Shakedown ◽  
Von Mises

Pressure distributions due to surface roughness in contact induce high stresses just beneath the surface. These stresses can bring on crack initiation and micro-pitting. A purely elastic contact model to account for these effects is restrictive because stress fields often exceed the yield strength of the material. Plastic flow occurs and modifies the surface shape and material properties (work hardening). This paper presents a numerical model for elastoplastic rough contact. It allows the determination of real pressures and permanent surface displacements (flattening of asperities) as well as residual stress and plastic strains useful in fatigue analysis). The material is assumed to obey the Von-Mises yield criterion with linear kinematic hardening. Real surface profiles obtained from a measurement can be considered. In addition, simplified methods have been used to treat cyclic loading. Thus the ability of a rough surface to reach an elastic shakedown state can be investigated, even for a three-dimensional contact found, for instance, in roller bearings.

Finite Element Analysis of Vacant Tubular Members under Static Loading Considering the Tip Shapes of Load

2014 ◽  
Vol 575 ◽  
pp. 497-500
Author(s):  
Mahmud Kori Effendi ◽  
Shuhei Zaitsu ◽  
Hiromitsu Kawaguchi ◽  
Akihiko Kawano ◽  
Shintaro Matsuo ◽  
...  
Keyword(s):  
Static Loading ◽  
Isotropic Material ◽  
Yield Criterion ◽  
Kinematic Hardening ◽  
Deformable Body ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Element Analysis ◽  
Fem Model ◽  
Von Mises

FEM analysis of MSC. Marc program is used to simulate the models. Three-dimensional FEM model with contact analysis between deformable body of specimens and rigid body of load are studied. The isotropic material and The Von Mises yield criterion are used and kinematic hardening is used as a flow plasticity model. The effect of various shapes of loading tips is investigated. The load-displacement were established. The results of these works are expected to be a useful reference for analyzing structures under various shapes of loading tips either static or dynamic loading.

Determination of Three-Dimensional Body Forms from Given Pressure Distribution Over Their Surfaces

1996 ◽  
Vol 40 (01) ◽  
pp. 22-27
Author(s):  
V. M. Pashin ◽  
V. A. Bushkovsky ◽  
E. L. Amromin
Keyword(s):  
Pressure Distribution ◽  
Three Dimensional ◽  
Bodies Of Revolution ◽  
Design Constraints ◽  
Pressure Distributions ◽  
Axisymmetric Bodies

A method for solving inverse three-dimensional problems in hydromechanics is proposed which makes it possible to fit desired pressure distributions within design constraints immediately in the course of calculations. Examples of the method of application are given for bodies of revolution in flows at nonzero drift angles. These flows are not axisymmetric. Bodies of revolution in them are very handy examples of demonstrations of the method, and these examples have many technical applications.

Overstraining of flush plain cross-bored cylinders

2004 ◽  
Vol 218 (2) ◽  
pp. 143-153 ◽  
Author(s):  
J M Kihiu ◽  
G O Rading ◽  
S M Mutuli
Keyword(s):  
Finite Element Method ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Yield Condition ◽  
Solution Technique ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
Incremental Theory Of Plasticity

A three-dimensional finite element method computer program was developed to establish the elastic-plastic, residual and service stress distributions in thick-walled cylinders with flush and non-protruding plain cross bores under internal pressure. The displacement formulation and eight-noded brick isoparametric elements were used. The incremental theory of plasticity with a 5 per cent yield condition (an element is assumed to have yielded when the effective stress is within 5 per cent of the material yield stress) and von Mises yield criterion were assumed. The frontal solution technique was used. The incipient yield pressure and the pressure resulting in a 0.3 per cent overstrain ratio were established for various cylinder thickness ratios and cross bore-main bore radius ratios. For a thickness ratio of 2.25 and a cross bore-main bore radius ratio of 0.1, the stresses were determined for varying overstrain and an optimum overstrain ratio of 37 per cent was established. To find the accuracy of the results, the more stringent yield condition of 0.5 per cent was also considered. The benefits of autofrettage were presented and alternative autofrettage and yield condition procedures proposed.

Contact Analysis of Multilayered Elastic/Plastic Solids With Rough Surfaces for Decreasing Friction and Wear

2005 ◽  
Author(s):  
Shaobiao Cai ◽  
Bharat Bhushan
Keyword(s):  
Surface Roughness ◽  
Contact Area ◽  
Yield Criterion ◽  
Rough Surfaces ◽  
Three Dimensional ◽  
Surface Displacement ◽  
Maximum Displacement ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Von Mises

A numerical three-dimensional contact model is presented to investigate the contact behavior of multilayered elastic-perfectly plastic solids with rough surfaces. The surface displacement and contact pressure distributions are obtained based on the variational principle with fast Fourier transform (FFT)-based scheme. Von Mises yield criterion is used to determine the onset of yield. The effective hardness is modeled and plays role when the local displacement meet the maximum displacement criterion. Simulations are performed to obtain the contact pressures, fractional total contact area, fractional plastic contact area, and surface/subsurface stresses. These contact statistics are analyzed to study the effects of the layer-to-substrate ratios of stiffness and hardness, surface roughness, and layers thickness of rough, two-layered elastic/plastic solids. The results yield insight into the effects of stiffness and hardness of layers and substrates, surface roughness, and applied load on the contact performance. The layer parameters leading to low friction, stiction, and wear are investigated and identified.

The effects of interfacial debonding on the elastoplastic response of unidirectional silicon carbide—titanium composites

2010 ◽  
Vol 224 (2) ◽  
pp. 259-269 ◽  
Author(s):  
M J Mahmoodi ◽  
M M Aghdam ◽  
M Shakeri
Keyword(s):  
Volume Fraction ◽  
Yield Criterion ◽  
Fibre Volume Fraction ◽  
Three Dimensional ◽  
Fibre Volume ◽  
Interfacial Debonding ◽  
Successive Approximation Method ◽  
Interface Damage ◽  
The Matrix ◽  
Von Mises

A three-dimensional micromechanics-based analytical model is presented to investigate the effects of initiation and propagation of interface damage on the elastoplastic behaviour of unidirectional SiC—Ti metal matrix composites (MMCs) subjected to off-axis loading. Temperature-dependent properties are considered for the matrix. Manufacturing process thermal residual stress (RS) is also included in the model. The selected representative volume element consists of r× c unit cells in which a quarter of the fibre is surrounded by matrix sub-cells. The constant compliance interface model is used to model interfacial debonding and the successive approximation method together with von Mises yield criterion is used to obtain elastoplastic behaviour. Dominance mode of damage including fibre fracture, interfacial debonding, and matrix yielding and ultimate tensile strength of the SiC—Ti MMC are predicted for various loading directions. The effects of thermal RS and fibre volume fraction on the stress—strain response of the SiC—Ti MMC are studied. Results revealed that for more realistic predictions, both interface damage and thermal RS effects should be considered in the analysis. The contribution of interfacial debonding and thermal RS in the overall behaviour of the material is also investigated. Comparison between results of the presented model shows very good agreement with the finite-element micromechanical analysis and experiment for various off-axis angles.

Three-Dimensional Thermo-Mechanical Finite Element Simulation for Casting Ladle Structure under Thermal Loadings

2008 ◽  
Vol 575-578 ◽  
pp. 1-6
Author(s):  
Shou Ju Li ◽  
Ying Xi Liu ◽  
He Yu
Keyword(s):  
Finite Element ◽  
Shell Structure ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Element Model ◽  
Steel Shell ◽  
Casting Ladle ◽  
Lining Structure ◽  
Calculation Results ◽  
Von Mises

The finite element model of coupling the thermal field with structural analysis is proposed in order to analyze the thermo-stress of casting ladle structure. The thermal fields of casting ladle with refractory lining structure are computed according to the thermal properties of materials and boundary conditions. Numerical simulation shows that that computed outer temperatures of casting ladle agree with measured ones. The thermo-stress of casting ladle structure is simulated by taking thermal loadings as the loading conditions of the steel shell structure. Material behaviors were described by the Drucker–Prager plasticity model and Von Mises yield criterion. Calculation results of thermo-stress fields shows the outer shell structure is safety under the action of thermal loadings.

scholarly journals 3D Finite Element Analysis of PWA-Oil Sand Terrain System Interaction

2012 ◽  
Vol 2012 ◽  
pp. 1-10
Author(s):  
Y. Li ◽  
S. Frimpong ◽  
W. Y. Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Contact Area ◽  
Oil Sands ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Oil Sand ◽  
Element Analysis ◽  
Nodal Displacement ◽  
Von Mises

A simulator for analyzing the interaction between the oil sand terrain and a pipe wagon articulating (PWA) system has been developed in this paper. An elastic-plastic oil sand model was built based on the finite element analysis (FEA) method and von Mises yield criterion using the Algor mechanical event simulation (MES) software. The three-dimensional (3D) distribution of the stress, strain, nodal displacement, and deformed shape of the oil sands was animated at an environmental temperature of 25°C. The 3D behavior of the oil sand terrain was investigated with different loading conditions. The effect of the load and contact area on the stress and nodal displacement was analyzed, respectively. The results indicate that both the max stress and max nodal displacement increase with the load varying from 0 to N and decrease with the contact area varying from 2 to 10 m2. The method presented in this paper forms the basis for evaluating the bearing capacity of oil sand ground.

Three-Dimensional Visual Modeling Technology and Application of Open Pit Mining Boundary

2012 ◽  
Vol 524-527 ◽  
pp. 790-793 ◽  
Author(s):  
Xiao Ming Yan ◽  
Zi Long Zhou ◽  
Xi Bing Li
Keyword(s):  
Three Dimensional ◽  
Digital Terrain Model ◽  
Surface Shape ◽  
Topographic Maps ◽  
Open Pit ◽  
Open Pit Mining ◽  
Real Surface ◽  
Three Dimensional Model ◽  
Model Stability ◽  
Visual Model

With mining depth and state-wide expansion in open pit mining, it is necessary to bulid a three-dimensional visual model of open pit mining boundary, which can be used in the analysis of pit slope stability, engineering decisions, geological analysis and production planning. In this paper, a three-dimensionla visual model reflecting the complex formation load and terrain conditions was built by collecting original open pit design and geological data. With this model, stability analysis of open pit can be obtained and theoretical basis for selection of design can be provided. In the specific prcess of modelling, the original information in the existing CAD mining topographic maps were be used fully and the mine topographic maps was imported into Surpac mining software. Surface digital terrain model can be obtained elevation assignmented by corrction processing of CAD linears and vector processing of measring point data. On this basis, by using MIDAS software and considering the requirements of the scope of computational space, a three-dimensional model can be obtained through Boolean cut operations. With this model, the real surface shape of open pit mining boundary can be reflected.

Evaluation of Burst Pressure of Corroded Pipe Segments Using Three-Dimensional Finite Element Analyses

2018 ◽  
Author(s):  
Ji Bao ◽  
Shulong Zhang ◽  
Wenxing Zhou ◽  
Shenwei Zhang
Keyword(s):  
Finite Element ◽  
Yield Criterion ◽  
Three Dimensional ◽  
Full Scale ◽  
Burst Pressure ◽  
Dimensional Finite Element ◽  
Tresca Criterion ◽  
Von Mises ◽  
Three Dimensional Finite Element ◽  
The Impact

In this paper, three-dimensional finite element models are developed to simulate full-scale burst tests of corroded pipes containing multiple naturally occurring corrosion anomalies. Both the von Mises and Tresca yield criteria and associated flow rules are employed in finite element analysis (FEA). For the Tresca criterion, the corresponding constitutive model subroutine is developed and incorporated in the FEA. The accuracy of FEA is investigated by comparing the burst pressures observed in the tests and corresponding burst pressures predicted using FEA. The implications of using the von Mises and Tresca criteria for the accuracy of the predicted burst pressure are investigated. Sensitivity analyses are also carried out to investigate the impact on the predicted burst pressure due to the mesh density in the corroded region, characterization of the geometry of the corrosion cluster and different types of element (e.g. solid and shell elements) used in FEA. The results suggest that the Tresca criterion always underestimates the burst pressure and the von Mises yield criterion predicts the burst pressure accurately. This study demonstrates the feasibility of using high-fidelity FEA and the Tresca yield criterion to simulate full-scale burst tests of corroded pipes and therefore establish a large database of burst pressure capacities of corroded pipes that can be used to develop an accurate, practical burst pressure capacity model amenable to the pipeline integrity management practice.

Effects of the Yield Criterion on Predicted Fracture Responses of Pipelines Subjected to Large Plastic Deformation With and Without Internal Pressure

2010 ◽  
Author(s):  
Alexandre Kane ◽  
Erling O̸stby ◽  
Odd-Geir Lademo ◽  
Torodd Berstad ◽  
Odd Sture Hopperstad
Keyword(s):  
Internal Pressure ◽  
Yield Surface ◽  
Structural Integrity ◽  
Yield Criterion ◽  
Surface Shape ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
Safety Level ◽  
Standard Material ◽  
Von Mises

The structural integrity of offshore pipelines is of vital importance for safe oil and gas transport. To ensure the required safety level, non-linear Finite Element (FE) analyses are necessary to perform fracture assessment of pipes under various, realistic loading conditions. Many standard material models, as found in commercial FE codes, pre-suppose the yield criterion of von Mises. This choice provides in many cases reasonable accuracy, certainty and engineering designs, but for some materials and application areas, it is much too inaccurate. In this work, 3D elastic–plastic FE simulations of pipes with internal surface cracks have been carried out. The aim of the work is to evaluate the influence of the yield criterion on the predicted fracture response. Analyses are performed on pipes loaded in tension, with and without internal pressure. The model shows that the yield surface shape may have a significant effect on the predicted evolution of Crack Tip Opening Displacement (CTOD). If the internal pressure is weak, a reduction in strain capacity is observed when the yield surface shape is varied from the rounded von Mises towards the cornered Tresca-like yield surface.

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