Large deformation finite element analysis of undrained. By using a software abaqus to build a threedimensional model, the process of mmp pile driven at a site of railway foundation in shanghai is simulated using theory of biot consolidation and modified camclay model with threedimension effect being considered. Modeling the powder compaction process using the finite. Effective stress versus total stress analysis of undrained. This option is used to specify the plastic part of the material behavior for elasticplastic materials that use the extended cam clay plasticity model.
A geostatic procedure with maximum displacement tolerances is supported only for the following materials. Surface subsidence, environment, cam clay, geomechanics, hydrocarbon production. If this parameter is omitted, the cam clay parameters may depend only on temperature. Elasticity with constant shear modulus and butterfield compression law linear normal compression lines in the vs.
Geyang song on hypoplastic interface model stutz et al. All these models are conservative and do not contain modern concepts of soil. Analysis of driven pile setup with abaqusstandard summary. Which software has the feature to model soil settlement due water drawdown.
Integration of anisotropic modified cam clay model in finite. Main ideas introduced in soil plasticity constitutive model. Numerical modelling of pipesoil interactions ii results were presented in terms of plastic failure envelopes in the vh load space for different initial embedments. Modified cam clay model the modified cam clay model was proposed by roscoe and burland 3 and a description and systematic study of the model can be found in the text by muir wood 8. Thermalhydromechanical model for freezing and thawing of soils by yao zhang a dissertation submitted in partial fulfillment of the requirements for the degree of doctor of philosophy civil engineering in the university of michigan 2014 doctoral committee professor radoslaw l. The specific model implemented is an extension of the modified camclay theory.
Download the abaqus unified fea brochure to learn more about the features and advantages of using abaqus as your cae software. On the other hand, in the cap model, both the fixed and moving surfaces are used to define the yielding process. Undrained excavations were modelled in abaqus, a software application for finite element analysis. Hans henning stutz on how to implement this hypoplastic interface model into abaqus combined with the existing hypoplastic model subroutine. The results of the analysis were compared with an unreinforced pavement sections at the same geometry and material properties. Abaqus unified fea product suite with simulia support from. Ground water in abaqus finite element camclay model. Some analyses with the ratedependent model are displacementcontrolled, while others model the e. I had a look at your model and i think that the problem lies deeper than in material definition. Simulia delivers a scalable suite of unified analysis products that allow all users. Comparative study between druckerpragercap and modified cam. Introduction the study of hydrocarbon production from an underground reservoir involves two basic elements. It includes leading and industry proven software, such as abaqus, fesafe, tosca, isight, simpack, cst, xflow, and others.
The changes in the excess pore pressure are obtained. Numerical and theoretical verification of modified cam. To accomplish this task, a reduced integration element is used that would take advantage of the abaqus modeling software. Sand hypoplastic model is an advanced incrementally nonlinear constitutive model.
Numerical implementation for subloading camclay model in abaqus. The steady state lateral residual resistance was then studied using large deformation analyses and an appropriate soil constitutive model. The drucker prager model provided in the abaqus abaqus 6. In this paper, a numerical undrained analysis of pile jacking into the subsoil using abaqus software suit has been presented. Table a1 basic dimensions height 3000mm width 1560mm thickness 200mm slab 2500x2500x500mm raft 2500x2500x400mm extra axial load on shear wall 8. Abaqus software for the fe solution, and abaqus post for the postprocessing of the results. The yield criterion of modified cam clay model was used to describe the plastic properties of soft clay, and the overstress theory was used to describe the strain rate effect. What is this error in abaqus when define material with cam. Especially for wheels with a deformable rim operating on.
Numerical and experimental studies of shallow cone. Assessment of tractive performances of planetary rovers. Modified cam clay model parameters in abaqus from triaxial tests. Use the concrete model available with rebar to model the reinforcements. The subroutine umat special for userdefined material model in the commercial fem software abaqus is utilized and the implicit integration algorithm for the modified camclay model is numerically. Reservoir compaction, surface subsidence, environment, cam clay, geomechanics, hydrocarbon production. By using a software abaqus to build a threedimensional model, the process of mmp pile driven at a site of railway foundation in shanghai is simulated using theory of biot consolidation and modified cam clay model with threedimension effect being considered. Composites modeler for abaquscae complements and extends the powerful ply modeling features in abaquscae by providing proven fiber simulation capabilities and advanced model buildingall seamlessly integrated within abaquscae. Value of the hydrostatic pressure stress at yield, p c or p t. Modified camclay triaxial test simulations 1 introduction this example simulates a series of triaxial tests which can be used to verify that modified cam clay constitutive model is functioning properly. Burland 1965 suggested a modified version of the cam clay model and this model was subsequently extended to a general threedimensional stress state by roscoe and burland 1968. Kinzler institute for geotechnics and construction management, hamburg university of technology.
I am interested to model soft soil of embankment using modified cam clay model. Abaqus contact modeling is extremely robust, and setting it up is easier than ever use automatic contact. Modified cam clay model mcc the mcc model was originally developed for triaxial load conditions. Experimental measurements on soft clays provided the background for the development of the constitutive model expressing the variation of void ratio e volumetric strain.
Abaqus keywords reference manual specify hardening for the clay plasticity model. Having had zero experience in soil mechanics, i am struggling to get to grips with all the terminology and finding a complete data set to try a test run of my model. An elasticviscoplastic model for timedependent behavior of. I tried running my model with an inbuilt material clay plasticity and im getting results. A two dimensional axisymmetric model was established in commercial finite element software abaqus with both soil water coupling effective stress and. Two different approaches, including traditional finite element method fem and arbitrary lagrangianeulerian ale formulation, were tested. Based on the results of the previous works related to studying the applicability of the cam clay model wagle et al. Burland 1965 amended the cam clay model solution and proposed the modified cam clay mcc model with roscoe in 1968. Numerical simulation of compaction and subsidence using. For this reason, the cap model is referred to as a cam clay model and has been used in the analysis of nonlinear behavior of powder forming processes crawford and lindskog 1983, trassoras, et al, 1989 and haggblad and oldenburg 1994. Im not an expert in geomechanics field but, from what i know about this kind of abaqus simulations, they require special attention when defining initial stress field.
These are elastoplastic models and their schematic representations in the pq plan where p is the hydrostatic stress and q is the mises equivalent stress are shown in fig. An elasticviscoplastic model for timedependent behavior. In general, the use of other materials with this procedure may lead to poor convergence or no convergence of the analysis. Numerical simulation of compaction and subsidence using abaqus. I have modeled the similar problem in afena but in 2d.
I have been trying to model the cyclic behaviour of soil. The user subroutine umat for userdefined material behaviors in commercial fem code abaqus is utilized for subloading camclay model. Finite element analysis of clay shear band under plane strain. Highperformance abaqus simulations in soil mechanics. Abaqus keywords reference manual clay plasticity clay plasticity specify the extended cam clay plasticity model. The modified cam clay model enhanced by the effects of structure in the same way as the structured hypoplastic model, see for the mathematic formulation. But when im using umat, it is creating lot many errors like numerical singularity and excessive distortion. Caelynx has built lifelong careers using abaqus unified fea to help some of the worlds biggest manufacturers make better, more competitive products. This soil model is the distinguished camclay model there.
The abaqus dassault systemes 2009 software was used for this purpose. What material properties need to be specified in modeling concrete with reinforcements. Formulations of this model suitable for use in finite element analysis can also be found in various texts e. Based on the platform of software abaqus, the userdefined material subroutine umat interface is developed to generate corresponding constitutive subroutine of the modified camclay model. Simulia is a complete suite of powerful and realistic solutions that enable users to explore the realworld behavior of product, nature, and life. Why make caelynx your abaqus vendor and support partner. Camclay theory provides a reasonable match to the experimentally observed behavior of saturated clays and belongs to the family of critical state plasticity models developed by roscoe and his colleagues see roscoe and burland1968and schofield and wroth1968. Coupled consolidation analysis of pipesoil interactions.
Clay hardening massachusetts institute of technology. It can be used only in conjunction with the clay plasticity option. To describe the timedependent behavior of soft clay, this paper extended onedimensional nishihara model to threedimensional stress state based on the framework of perzynas overstress theory and modified cam clay model. The mcc model can be used to predict the stressstrain behavior of clay on wet side. Ground water in abaqus finite element cam clay model. The druckerpragercap dpc model and the modified cam clay mcc model were used in this numerical modeling.
Composites modeler for abaquscae directly transfers accurate fiber angles and ply thicknesses to abaqus. The subroutine umat special for userdefined material model in the commercial fem software abaqus is utilized and the implicit integration algorithm for the modified cam clay model is numerically. Hi, can anyone explain what is the difference between mohrcoulomb model and modified cam clay model when predicting settlement of soil, either sand or clay, wh modeling soil settlement in abaqus dassault. Numerical implementation of implicit integration algorithm. The clay shear band analysis under plane strain condition were based on modified cam clay model in finite element software abaqus. V,rama rao,sharad purohit a stepbystep procedure for modeling and analysis of rc shear wall in abaqus is explained.
The specific model implemented is an extension of the modified cam clay theory. A hypoplastic model for clays, basic version, version with structure, both with and without intergranular strain concept modified cam clay model incorporating structure three surface kinematic hardening model 3skh 7,8 with small strain elasticity from. The material model employed for the clay and gravelly material is an elastoplastic druckerprager model. And using this subroutine umat, a series of numerical. Modified cam clay the worlds leading software development. Modeling of rc shear wall in abaquscae renish dhaduk,g. The inelastic constitutive theory provided in abaqus standard for modeling cohesionless materials is based on the critical state plasticity theory developed by roscoe and his colleagues at cambridge schofield et al. The yield surface of both models presents at least a part with an elliptical shape.
The extended modified cam clay model was used to characterise the soil behaviour in the effective stress analysis esa and the tresca model was used in the total stress analysis tsa. Clay plasticity massachusetts institute of technology. Data lines to define hardening for cam clay plasticity first line. Abaqus unified fea product suite with simulia support. Can anyone extend cooperation, how to model soft soil in abaqus using modified cam clay. Our knowledge of soil mechanics comes from human practice. Abaqus software package to conduct a three dimensional fe analysis to model the. Finite element modeling of pile setup can help in obtaining reliable estimates of the increase in pile resistance, which would allow for reductions in pile lengths, pile sections, or. For this purpose, the element has been implemented in abaqusstandard finite element software. Weve been able to accomplish this because the software works, and it works very well. User defined subroutine umat for advanced constitutive models. I choose cam clay model for soft soil and want to define cohesion for it.
Numerical and experimental studies of shallow cone penetration in. My initial analysis runs without any issue and when the deformations reach a certain level, i create another mesh and use map solution command to transfer variables as initial conditions to the new mesh. Hi everyone i want to define properties of cam clay plasticity constitutive model in abaqus. Abaqus software is a modification of the druckerprager strength hypothesis 9. A brief introduction to critical state theory in soil mechanics. The modified cam clay is an elastic plastic strain hardening model. The yield criterion of modified cam clay model was used to describe the plastic properties of soft clay, and the overstress theory was used to describe the strain. Soil plasticity and the structured cam clay model i. The integration algorithm developed for the anisotropic modified cam clay model is implemented into the finite element analysis commercial program, abaqus, through the material interface of umat, which calls the relevant data from the main program and returns the updated values. The goal of the formulation and implementation of this speci. Numerical modelling of undrained vertical load displacement. Hi everybody, i want to know that if the soil has cohesion and i want to model it by cam clay model, how can i input cohesion in material property. Comparative study between druckerpragercap and modified.
Druckerpragercap mdpcap model are employed in the abaqus finite element analyses to simulate the stressstrain be. This example is a simple demonstration of the modified camclay plasticity model provided in abaqus. This soil model is the distinguished cam clay model thereafter. This option is used to define piecewise linear hardeningsoftening of the cam clay plasticity yield surface. Flac, fast lagrangian analysis of continua, is 2d numerical modeling software for advanced geotechnical analysis of soil, rock, groundwater, and ground support. Actually, i am modeling embankment on soft soil for consolidation process.
Statistical analysis of modified druckerprager cap model. Finite element analysis of clay shear band under plane strain condition. Data lines to define hardening for cam clay plasticity. Derivation of parameters and calibration of modified cam clay. A gnu octave matlab code for modified cam clay in fe formulation for element testing drained and undrained hansinimalcamclay. Then, for the first time, numerical simulation of the two tests was performed by threedimensional finite element method fem using abaqus program.
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