01. Preprocessing 02. 03. 04. 05. 06. - · PDF filemidas GTS V200 Release Notes 01....

midas GTS V200 Release Notes

01. Preprocessing

02. Material models

03. Elements

04. Analysis

05. Post-processing

06. Additional Features, Enhancements & Bug Fixes

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http://eng.midasuser.com/gts/

01. Preprocessing

1. Enhanced Framework

The latestest framework of GTS V200 provides a more intuitive and versatile working environment. Especially, Task Pane enables the user to customize the menus for his favorite tasks. It maximizes the operational efficiency of the user. Since the user can arrange the menus by his own work flow for each analysis type, it helps the user generate anlaysis models with much less time and effort. In addition, by locating all favorite functions in a single window, the user invokes a desired menu swiftly without searching through the menu system. It eliminated the disadvantage of working in a Windows-based GUI.

GTS consists of various analysis types such as Linear/Nonlinear Static, Construction Stage, Slope Stability, Seepage, Eigenvalue, Seismic Response Spectrum, Time History, and Consolidation. For each analysis type, analysis conditions (i.e. loads and boundaries) are defined differently. As such the user should apply them with good understanding of applications and experience in numerical analysis. In the previous versions of midas GTS, the user guided himselves through complex analysis procedures with their own knowledge. However, with the provision of all the necessary features in a specific analysis in the Task Pane, the user can follow the menus in a step by step workflow. In addition, GTS enables the user to customize his own favorite analysis procedures. It provides the following 3 major aspects of functionality.

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Task Pane Functionality

Task Pane: It can recall the last saved files, and in addition, the user can import the

customized User Defined Task Pane. Analysis: It contains walk-through procedures for 8 analysis functions provided by GTS. User Define: The user can find and run the functions that have been imported from the

user defined task pane file.

2. Auto Generation of Ground Support

Previously, it was necessary for the user to define each boundary nodes with relevant directional contraints when applying ground supports. This method is useful when directly assigning boundary conditions to the desired nodes. However, in the case of general stability analysis that does not include specific boundary conditions, it will be a tedious task to assign ground supports manually. In GTS V200, a function of auto-generating ground supports has been added.

Functionality Automatically constrain the horizontal displacement degree-of-freedom of nodes having

the maximum/minimum X coordinate. Automatically constrain the vertical displacement degree-of-freedom of nodes having

the minimum Y coordinate. Automatically constrain the horizontal displacement degree-of-freedom of nodes having

the maximum/minimum Z coordinate in a 3-dimensional space.

Subway Tunnel Pile Analysis Untitled S.T.Y Tunnel Foundation Consolidation Test

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Usage

Select ‘Model > Boundary > Ground Support’. Select a boundary condition name from BC Set. Select Mesh Set(s) to which boundary conditions will be assigned. Check on ‘Consider All Mesh Sets’. When ‘Consider All Mesh Sets’ is checked on,

peripheral grounds and contiguous boundaries will not be assigned with ground supports.

Click ‘Apply’ and confirm that ground supports are generated on the periphery of the selected Mesh Set(s).

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3. Division of 3D Elements

A 3D mesh often needs to be refined for detailed analysis results. In GTS V200, a function for dividing 3D elements has been added for the user’s convenience. This function is useful when generating a Hexa Mesh, which ensures the accuracy of the analysis results. The description and the usage of the function are as follows:

Functionality

Discretize 3D elements depending on the methods.

Usage

Select ‘Model < Element < Divide 3D’. Select elements to be divided. Select a method of dividing elements. ‘Divide by Pattern’ divides elements by selecting

a division pattern and a reference point. ‘Divide by Number’ divides elements by selecting an axis and entering the number of divisions in the selected axis.

Click on ‘Apply’ and confirm that the selected elements are divided.

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4. Improvement in Protrude Mesh

‘Protrude Mesh’ creates 1D, 2D and 3D elements by protruding nodes, edges, 1D elements and 2D elements. In the older versions, 3D elements could not be created directly from other 3D elements. In order to create 3D elements by protruding other 3D elements, 2D elements had to be extracted from the Faces of the 3D elements and then the 2D elements were protruded into new 3D elements. In GTS V200, for the user’s convenience, this function has been improved so that 3D elements can be directly created by extruding, revolving, sweeping, projecting or offsetting Faces of other 3D elements. As an example, ‘Extrude Mesh’ will be presented.

Functionality

Using Faces of 3D elements, new 3D elements can be extruded into a desired direction. ‘Extrusion Direction’ can be selected among the axes (X, Y and Z) of the basic

coordinate sytem or directly defined by a 2-Point Vector. If Offset Components (Dx, Dy, Dz) is selected, the extrusion lengths in the x, y and z directions can be specified.

Enter the extrusion length in the ‘Offset’ entry field and enter the number of elements to be created in the ‘Number of Times’ entry field.

Usage

Select ‘Mesh > Protrude Mesh > Extrude’. Select ‘EFace->3D’ tab. Select Face(s) of 3D elements. Select the ‘Extrusion Direction’ method and specify ‘Offset’ and ‘Number of Times’. Define material properties for the 3D elements to be extruded, from ‘Attribute’. Click on Preview and confirm that the Mesh is generated correctly.

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5. User-defined View Point

View manipulation such as zooming in/out (Mouse Wheel), rotating (Ctrl+Drag while right-clicking) and moving (Ctrl+Drag while pressing the mouse wheel) in the Work Window can be executed using various functions in the View Toolbar. Although the View Point can be freely changed as the user wishes, a specific View Point often needs to be saved for repeated use. In GTS V200, the View Point from a desired position and angle can be saved and be restored when necessary.

Functionality

Save the View Point (Zoom In/Out, Rotate and Move) that the user frequently uses. Import or export the saved View Point.

Usage

Right-click on the ‘View Point’ of ‘Pre-Works Tree’ to invoke the Context Menu. Select

‘Save Current View point’ and enter a name so as to save the current View Point or select ‘Import View Point’ to import a previously saved View Point (*.vpd).

Double click the saved View Point to revert to the View Point while working on another View Point.

Right-click on the saved View Point of ‘Pre-Works Tree’ to invoke the Context Menu. Select ‘Delete View Point’ to delete the saved View Point or select ‘Export Current View point’ to save as a separate file (*.vpd).

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6. Improvement in View Manipulation

In GTS V200, the following shortcut keys for the frequently used View functions have been added for usability.

Shift + Arrow keys: Move (Pan) In general, the Work Window is moved using ‘Ctrl+Drag while pressing the mouse wheel’.

Using the aforementioned shortcut, the Work Window can be moved as much as the mouse drags. In order to move the model by a constant distance, press arrow keys while pressing the Shift key, which is a newly added function.

Ctrl + Arrow keys: Rotate Using ‘Ctrl+Drag while right-clicking’, the Work Window is rotated. In GTS V200, a new

function has been added so that the Work Window can be rotated by a defined angle pressing the arrow keys while pressing the Ctrl key.

‘+/-’ keys on the number keyboard: Zoom-in/out Using ‘Mouse Wheel’, the Work Window is zoomed in/out. Using ‘Mouse Wheel’, the Work Window can be zoomed in/out as much as the mouse drags. With a newly added function, the Work Window can be magnified or shrunk at a constant ratio by pressing +/- keys on the number keyboard.

‘*’ key on the number keyboard: Zoom Fit Using the shortcut key ‘Ctrl+Q’ or the icon in the View Toolbar, ‘Zoom Fit’ fits the entire model

into the Work Window. In GTS V200, simply click the * key on the number keyboard to use ‘Zoom Fit’.

‘/’ key: Initial View Initial View removes the analysis results output and returns back to the Mesh Set state. In the

old versions, only the Initial View icon on the Post Command toolbar was used. In GTS V200, the / key has been added for convenience.

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02. Material models

1. Modified Mohr-Coulomb Model

The Modified Mohr-Coulomb model is an advanced Mohr-Coulomb model with a hardening cap and is suitable for any type of soils (stiff or soft). It is particularly suitable for granular materials such as silts and sand.

The Modified Mohr-Coulomb model can account for the following material behaviours that are

characteristic of soils: - Stiff unloading-reloading stiffness, Eur, compared to primary loading stiffnesses. - Effect of overconsolidation on stiffness change in compression loading. - Stress dependency of the unloading-reloading stiffness according to a power law. - Cohesion-frictional shear failure according to Mohr-Coulomb’s law. - Strain dependency of the tangential stiffness in primary shear loading (in triaxial test)

according to a hyperbolic law (Duncan & Chang model). - Evolution of the apparent dilatancy angle (from contractant to dilatant) in primary shear

loading according to Rowe’s rule. - Stress dependency of the tangential stiffness in primary compression loading (in

oedometer test) according to an exponential law. This constitutive behaviour is achieved by combining a non-linear elastic model with two

plastic models which display independent hardening behaviours (i.e. Double Hardening model). The unloading-reloading behaviour is described by non-linear elasticity with the elastic bulk

modulus varying according to a power-law: with pt the pressure shift due to cohesion: and Kref the unloading-reloading bulk modulus at reference pressure pref The unloading-reloading Poisson’s ratio remains constant. The shear behaviour is described by a smooth Mohr-Coulomb plastic surface, Fig. 1 and Fig 2.

Shear hardening is achieved by the variation of the friction angle from its initial value, φ0, to its ultimate value, φu. The strain dependent evolution of the friction angle is specified to match the Duncan Chang’s parabolic law at the reference pressure:

with ε1 the vertical strain, q the deviatoric stress and qa the assymptotique shear stress.

m

ref

treft p

ppKK ⎟⎟⎠

⎞⎜⎜⎝

⎛ −=

ut

cpφtan

=

⎟⎟⎠

⎞⎜⎜⎝

⎛−

=

a

ref

qqE

q

12 50

1ε

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The flow rule for shear hardening is non-associated. The adopted plastic potential is of Drucker-Prager type and is controlled by a dilatancy angle depending on the current friction angle according to Rowe’s rule:

with φcv the friction angle at zero dilatation The primary loading compression behaviour is described by an elliptic plastic cap with its

center at the apex of the Mohr-Coulomb surface, Fig.1: with pc the preconsolidation stress and α a shape ratio set to a default value of 2/9 The initial preconsolidation stress, pc ini, is computed based on the initial stresses and on the

specified values of K0 and Knc. Compression hardening is achieved by the variation of the preconsolidation stress according

to the following exponential law: with e0 the initial void ratio, εvp is the volumetric plastic strain and γ is the hardening coefficient

deduced from the oedometer modulus. The cap flow rule is associated.

Fig. 1 In p-q space Fig. 2 In deviatoric plane

cv

cv

φφφφψ

sinsin1sinsinsin

−−

=

uu

uucv ψφ

ψφφsinsin1sinsinsin

−−

=

( ) ct pqppf −⋅++= 22 α

⎟⎟⎠

⎞⎜⎜⎝

⎛ +⋅= vpcc

epp εγ

1exp 0ini

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The input parameters of Modified Mohr-Coulomb model are as follows:

Cohesion Cohesion, c

Friction Angle Initial friction angle, φ0 . Can be chosen close to zero.

Secant Stiffness in Tri-axial

test (E50ref)

Secant Young’s modulus at 50% of shear failure in a

triaxial test carried out under reference pressure, Pref

Tangential Stiffness primary

Oedometer test (Eoedref)

Tangential oedometer modulus at reference pressure,

Pref

Unloading/Reloading

Stiffness (Eurref)

Unloading-reloading Young’s modulus at reference

pressure, Pref

Reference Pressure (Pref) Reference pressure

Ultimate Dilatancy Angle Dilatancy angle at shear failure, ψu

Friction Angle at shear Friction angle at shear failure, φu

Power of Stress Level

Dependency

Parameter for the Power Law

Porosity Initial porosity

KNC K0 -ratio for normally consolidated soil

Forced Normal Consolidation This option can be used to force the constitutive model

to produce a normally consolidated stress state. It may

be usefull in particular in the stress initialization stage of

ground layers under a slope.

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2. User Supplied Material ‘User Supplied Material’ allows the user to implement the user-defined material of a nonlinear model in GTS solution and Pre/Post processor. Nonlinear elastic materials and elasto-plastic materials are the materials that can be implemented using ‘User Supplied Material’, and this function is applicable to plane strain elements (3, 4, 6 & 8-node), axisymmetric elements (3, 4, 6 & 8-node) and solid elements (4, 6, 8, 10, 15 & 20-node). Stress components for each element are defined as follows:

<Stress components for each element>

Element Stress Strain

Plane strain zzxyyyxx σσσσ ,,, zzxyyyxx εγεε ,,,

Axisymmetric zzxyyyxx σσσσ ,,, zzxyyyxx εγεε ,,,

Solid zxyzxyzzyyxx σσσσσσ ,,,,, zxyzxyzzyyxx γγγεεε ,,,,,

The procedure for using ‘User Supplied Material’ function is as follows:

Create a Fortran file

Create a DLL file

Implement in the modeling Detailed descriptions on ‘User Supplied Material’ are presented in the last part of this Release Notes.

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03. Elements

1. Geogrid Element

In GTS V200, a Geogrid element has been added to describe the properties of geotechnical fiber. Geotechnical fiber materials are high polymers used in combination with sands, clays, gravels, etc. and closely relate to geotechnical engineering works. They are used to prevent soil erosion and for filtering. Thereafter, they are used to dismantle, reinforce and drain soils, and recently they are used for waterproofing, preventing fissure, protecting underground structures and absorbing impact.

Geogrid elements are thin and flat structures, which do not retain flexural stiffness but retains axial stiffness. Geogrid elements cannot resist compression and can take tension only. In general, these elements are used for reinforcing soils. 2. Pile Element

In the older versions of GTS, when creating a pile-foundation with beam elements representing the concrete pile, and solid element representing the soil, compatibility must be preserved at each node of the beam-elements and corresponding nodes of solid elements, which is quite cumbersome. In GTS V200, the Pile element has been made available, which is a type of Embedded Beam element. The use of this element is convenient for 3-D modeling, because we are no longer required to preserve node connectivity and because we are able to consider (nonlinear) interface effects such as frictional slip of pile and soil. For a pile element both the properties of the Beam element as well as for the interface between pile and soil need to be defined. The input parameters of the Pile element are identical to those of Beam element. Interface properties to be considered for Pile element will be presented underneath.

Property

<Input Parameters>

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The diagram for the relative shear force per length as function of relative longitudional

displacement between pile and soil is defined at the Reference Depth. If the Slope of Friction-Rel. Disp curve is not actived or assigned with value 0, this diagram will apply to every point of the pile. However, when the Slope of Friction-Rel. Disp curve is activated, the diagram will become a function of depth because the vertical axis of the diagram will be corrected by the defined slope. Normal Stiffness of the interface is always equal to nK .

Parameter Description

Ultimate Shear force Ultimate shear force per length (Force/Length)

Shear Stiffness Modulus ( )tK Linear elastic penalty stiffness of the interface

in the longitudional direction of the pile. If this

option is chosen a tri-linear diagram is defined

for the relative shear-force per length as

function of relative longitudional displacement

between pile and soil. This diagram is defined

by the ultimate shear force value (1st and 3rd

line-segment) and the shear stiffness modulus

(2nd line segment), (Force/Length*Length)

Function Multi-linear diagram can be specified for the

relative shear force per length as function of

relative longitudional displacement between

pile and soil. The veritical axis of the diagram

is dimension-less and will be multiplied by the

specified ultimate shear force value. The

horizontal axis is of dimension Length.

Normal Stiffness Modulus (Kn) Linear elastic penalty stiffness of the interface

in the directions normal to the pile.

(Force/Length*Length)

Reference Depth The reference depth for which the diagram as

defined above is applicable (Length)

Slope of Friction-Rel. Disp. curve The gradient of shear-force per length

diagram with depth (Force/Length*Length).

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An example model generated using Pile elements is illustrated below. 5 layers constitute soils.

A pier is on the soil and the lower part of the pier is composed of Pile elements. The soil and the structure retain their own self-weights and no external load is applied.

Tractions and relative displacements of Pile elements are produced with respect to the local

coordinate system. The displacements of the Pile elements and peripheral soils and the axial tractions of the Pile elements are displayed below. It is observed that the Pile elements greatly affect the soils on the periphery and the distribution of friction at the Pile elements and peripheral soils.

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Constitutive Equation

<Types of Interface Elements between Solid and Line Elements>

Solid elements of both lower order and higher order can be used for interface elements. The

following types of Solid elements can be used.

8-node/20-node Octahedron (Brick) 6-node/15-node Hexahedron (Wedge) 4-node/10-node Tetrahedron (Tetra)

The following types of Line elements can be used.

2-node Truss element 2-node Beam element

The global coordinate system for interface elements is as follows:

{ }321 XXX=X

The element local coordinate sytem for interface elements can be defined using the global

coordinate system as follows:

( ) ( ) ( ){ } { }32133

32

313

23

22

212

13

12

111 ,,,,,, XXXXXXxXXXxXXXx ==x

Elementary Coordinate y

z

x

Elementary Coordinate y

z

x

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The global coordinate system can be expressed as

IX =

The local coordinate system can be represented in terms of an orthogonal matrix as

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

=33

32

31

23

22

21

13

12

11

XXXXXXXXX

x

Nodal coodinates can be arranged using the local coordinate sytem as follows:

( ) ( ) ( ){ }

( ) ( ) ( ){ }TXXXxXXXxXXXxXXXXXXXXX

xxxxxxxxxxxx

33

32

313

23

22

212

13

12

111

33

32

31

23

22

21

13

12

11

33

32

313

23

22

212

13

12

111

,,,,,,

,,,,,,

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

=

=x

The quadratic shape function can be plotted and written as follows:

( ) ( )21 1

211

21 ξξ −−−=N , ( ) ( )2

2 1211

21 ξξ −−+=N , ( )2

3 1 ξ−=N

The shape function at the Gauss integration points is denoted by l

kN . Where k is the node number and l is the integration point number. If there are two integration points, l=1,2. The nodal coordinates can be expressed as k

ia using the node number, k and the number of degrees of freedom, i. For Solid elements, three translational degrees of freedom are used.

⎭⎬⎫

⎩⎨⎧

= ∑∑∑===

3

13

3

12

3

11 ,,

k

lk

k

k

lk

k

k

lk

kl NaNaNaa

la is the coordinate of the Gauss integration point of Line element in the element local

coordinate system. Since the coordinate of the integration point of Line element is known in the Isoparametric coordinate system of Solid element, the coordinate system of the integration point of Line element can be known in the element coordinate system of Solid element using the nodal coordinate of Solid element.

N1 N2N3

ξ

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The coordinates in the Isoparametric coordinate system are given by

{ }llll ζηξ ,,=α

If the basic element is a 15-node Wedge element, the shape function can be defined by

l

kN15

Where, k is the exponent of the shape function and l is the exponent of the integration point. If

three nodes pass through the 15-node Wedge element, the Relative Displacement-Displacement matrix can be formulated as follows:

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

−−−−

−−=

llll

llll

llll

l

NNNNNNNN

NNNN

311515

115

311515

115

311515

115

000000000000000000000000

LL

LL

LL

B

If three nodes pass through a 10-node Tetra element, the Relative Displacement-Displacement

matrix can be formulated as follows:

⎥⎥⎥

⎦

⎤

⎢⎢⎢

⎣

⎡

−−−−

−−=

llll

llll

llll

l

NNNNNNNN

NNNN

311010

110

311010

110

311010

110

000000000000000000000000

LL

LL

LL

B

The slope stiffness matrix of Solid-Beam interface element is

∑=

=np

lll

lTlt W

1det JTBBK

Where, tK is the slope stiffness, lW is the weight and T is the Relative Displacement-

Friction matrix.

The types of material models used for Solid-Beam interface elements include Linear Elastic

model and Nonlinear Elastic model. The Relative Displacement-Friction matrix is formulated as

follows:

y

z

xElementary Coordinate

{ }163

162

161

16 ,, aaa=a

{ }173

172

171

17 ,, aaa=a

{ }183

182

181

18 ,, aaa=a { }183

182

181

13 ,, aaa=a

{ }183

182

181

12 ,, aaa=a

{ }183

182

181

11 ,, aaa=a

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0 00 00 0

s

n

n

kk

k

⎡ ⎤⎢ ⎥= ⎢ ⎥⎢ ⎥⎣ ⎦

D

Normal stress (σ ) and shear stress (τ ) are associated with a constitutive equation which

relates them to normal strain and tangent strain. A 3-D structure retains one tangential strain and

two normal strains.

σ γτ ετ ε

Δ Δ⎧ ⎫ ⎧ ⎫⎪ ⎪ ⎪ ⎪Δ = Δ⎨ ⎬ ⎨ ⎬⎪ ⎪ ⎪ ⎪Δ Δ⎩ ⎭ ⎩ ⎭

D

The constitutive equation for nonlinear elastic model is determined by the slope of the

following graph:

Once the user defines the graph at the Reference Depth and the Slope of Friction-Rel. Disp.

curve with depth, the depth of the integration point at which friction is to be calculated for Solid-

Beam interface element will be automatically calculated. And the variation of the graph with

depth will be automatically calculated using the Slope of Friction-Rel. Disp. curve in order to

calculate internal forces and slope stiffnesses.

Relative displacement

Force per length of pile

Depth=1

Depth=2

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04. Analysis

1. Restart Function

While running the construction stage analysis, the user may stop at a mid-stage for a check, or it can be terminated due to system instability or by an accident. Depending on the analysis type and the number of analyzing stages, the analysis may require a very long time. If it has stopped due to unexpected termination, the user must spend wasteful time to run the analysis again from the first stage. In GTS, the restart function enables the user to continue from where it has last stopped It will reduce the total analysis time when faced with unexpected errors during the analysis.

Introduction

After the construction stage analysis is terminated, the function enables the user to start

again from the last saved analysis.

Usage

The restart option is specified from Analysis Case (Main Menu: Analysis > Analysis case). After selecting Construction State as an analysis type, click Analysis Control to invoke the Analysis Control dialog..

It provides 3 options to control the Restart function. ‘Save only user specified stages’ : It saves only specified stage by the user. ‘If not converged save its previous stage’ : It saves only the last converged stage. ‘Save all stages’ : It saves all stages.

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2. Drain Function

In order to show the characteristic of a drainage material, midas GTS provides Draining Condition in this version. The Drain Condition is applied in areas where the excess pore water pressure equals to zero, and it can be effectively used with the consolidation analysis and the ground water flow analysis provided by midas GTS. In consolidation analysis, nodes with the drain condition will have the pore water pressure of zero; the active pore water pressure becomes zero to allow drainage in the ground water flow analysis.

3. Well

GTS v200 allows user to control extraction and injection of water in specified nodes using the Well condition. The Well is controlled with existing Nodal Flux function, and it can describe the extraction and injection by adding ‘+’ and ‘-’ symbols in the value.

Usage

Select ‘Main Menu: Model > Boundary > Nodal Flux.’ Enter the name of BC Set. Select nodes for Well condition to be applied Enter the value of water extraction (‘-’ sign) or injection (‘+’ sign) in the Nodal Flux value

input box. Click the Apply button, and check if the boundary condition is added successfully.

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4. Consolidation Analysis Enhancement

In the new version, GTS has improved the performance of the consolidation analysis. The enhancement details are as follows:

By applying non-consolidation boundary condition (Model > Boundary > Non-Consolidation Condition) on embankment soil, the coupled analysis can be performed only in consolidating soil layers. Therefore, it enables the user to simulate not only saturated behavior but also partially saturated behavior.

The analysis is equipped with soil drain condition, which can carry the consolidation layer’s top and bottom drain control and vertical drain condition.

When the analysis is performed over uniform time interval, it takes relatively a very long time. In order to resolve this issue, it automatically generates the times and loading factor by selecting uniform or log scale interval.

The convergence performance has been improved for the Cam Clay or Modified Cam Clay material model.

Verical Disp. Behavior Dissipation of Excess Pore Water Pressure

5. Auto-recognition of Water Pressure

If it is modeled below water level, a structure will be influenced by water pressure. In order to account for this condition, GTS implemented automatic recognition function of the water pressure on structure.

6. Load from Results of Other Case The previous versions of GTS were only capable of bringing pore pressure as an initial stress load to perform the seepage-stress coupled analysis. GTS v200 provides a function that can consider effective stress resulting from any analysis case. In addition, applicable analysis type for the initial stress has been extended to linear static, nonlinear static, construction stage and coupled analysis types. Therefore, it is capable of performing coupled analysis using various analysis cases.

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05. Post processing

1. Deviatoric and Volumetric Plastic Strain

In GTS v200, deviatoric plastic strain and volumetric plastic strain can be checked in the post-processing.

Introduction

Stress tensor has two components, elastic and plastic.

pe εεε +=

Deviatoric plastic strain can be defined as follows:

2dev p 34 J=ε

whereas, ( ) ( ) ( ) ( )2 p

2 p

2 p

2 p p6

12 p p6

12 p p6

12 4

1zxyzxyxxzzzzyyyyxxJ γγγεεεεεε +++−+−+−=

Volumetric plastic strain can be defined as follows:

zzyyxxvol p p p p εεεε ++=

Usage

These plastic strain results can be displayed by double-clicking strain components

marked as Deviatoric or Volumetric.

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2. Elements Result Calculated at Nodes using Probe Result

Probe Result enables us to display nodal or element results using tags. Since some analysis results such as stress and strain are only computed at elements, their result display using Probe Result has been limited to element based output. In this new version, it is possible to display the element result values on a node. It automatically calculates average of all results of attached elements to the target node. The function is only available when Nodal Average is checked in Status Switch of Post Command Toolbar.

3. Absolute Maximum Display using Probe Result

In addition to Max and Min display capability, the absolute maximum value checking function has been added to Probe Result.

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4. Nodal Average per Group

Nodal average is used to display contour result. This method calculates average value at a node from pertaining elements. In the previous versions, the value was computed from all elements around the node. However, in GTS v200, users can designate groups of averaging elements based on Mesh Set, Property or Material.

Group Type

‘Same Mesh Set’ : It calculates average only within elements of the same Mesh Set. ‘Same Properties’ : It calculates average only within elements of the same Property. ‘Same Materials’ : It calculates average only within elements of the same Material.

Usage

Select a result component from the Post-Works Tree. Select Nodal Average in the Property Window. Select preferred option in Group Type.

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5. Mesh Edge Display – Free Face Wire Frame and Shading

4 new mesh edge display methods have been added to 3 existing methods.

Edge Display Methods

‘Free Face Wireframe’: It only displays element edges on free face boundary. ‘Shading (Wireframe, Feature Edge, Free Face Wireframe)’: ‘Shading’ displays all

elements in a mono-color. Edge display methods are the same as regular contour display.

Free Face Wireframe Shading (Wireframe)

Shading (Feature Edge) Shading (Free Face Wireframe)

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06. Additional Features, Enhancements, and Bug Fixes

1.New Feature -2006-10-31 <GUI/Windows-New Feature> When zooming by scrolling, pressing down crtl key will change its zooming center to the mouse pointer instead of screen center. -2006-12-09 <Label-New Feature> Toggle icons for element local axis, element number, and node number are added in Mesh Toolbar. - 2.Improvement -2006-09-07 <Mesh-Improvement> Domain recognition algorithm in Auto Mesh Planar Area has been improved. -2006-09-13 <Mesh-Improvement> While creating interface elements using the ‘From Beam/Plate’ method, elements on each side of Beam/Plate elements can be registered in a separate Mesh Set. -2006-10-31 <Mesh-Improvement> ‘Shape Display after Meshing’ has been added in Mesh Preference. It controls the display of geometry shape after mesh generation. -2006-12-05 <Misc-Improvement> A node/element can be selected using its ID in Query Node/Element. -2006-12-08 <Mesh-Improvement> Mid-node to Geometry option is added in Mesh Preference for Auto/Map Mesh generation. -2006-12-09 <Analysis-Improvement> Log Scale option has been added for defining Time Step for consolidation analysis.

-2006-12-12 <Mesh-Improvement> Auto-meshing speed for higher order elements is improved by 20%. -2006-12-13 <Property-Improvement> Section display for 1D element is improved (Speed/Graphic Quality). -2006-12-13 <Mesh-Improvement> D Delaunay Mesher and 3D Tetra Mesh are improved in both speed and shape quality.

-2007-01-10 <Mesh-Improvement> Change Parameter is improved in speed. -2007-01-11 <Analysis-Improvement> Memory is managed more efficiently in construction stage analysis.

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3. Bug Fix -2006-08-18 <Analysis-Bug Fix> Safety Factor calculation issue when underground water exists in Slope Stability Analysis has been resolved. -2006-08-18 <Analysis-Bug Fix> Problem in analysis result of 1D element in construction stage has been resolved. -2006-08-30 <Load-Bug Fix> Data transfer error in Initial Stress has been fixed. -2006-08-30 <Common-Bug Fix> Interface generation error for high order elements has been fixed. -2006-09-08 <Analysis-Bug Fix> Spring element problem in Construction Stage Analysis has been fixed. -2006-09-08 <Post-Bug Fix> Flow Quantity output error has been fixed. -2006-09-15 <Mesh-Bug Fix> An error with higher order element generation on cylindrical face has been fixed. -2006-09-20 <Analysis-Bug Fix> An error with Prescribed Displacement in Construction Stage Analysis has been fixed. -2006-09-29 <GUI-Bug Fix> Property Window problem has been fixed to update when the Apply button is pressed. -2006-09-29 <Mesh-Bug Fix> Detach Mesh problem has been fixed. -2006-10-02 <Mesh-Bug Fix> A seeding error with manual division in Auto-Mesh has been fixed. -2006-10-02 <Mesh-Bug Fix> An error with Grid Mesher with very small scale model has been fixed. -2006-10-08 <Post-Bug Fix> An error in displaying higher order elements in construction stage has been fixed. -2006-10-10 <Analysis-Bug Fix> Stress contour problem for quadratic tetra elements has been fixed. -2006-10-10 <Analysis-Bug Fix> An error in axial forces of rock bolts in quadrilateral elements has been fixed. -2006-10-16 <Property-Bug Fix> An error in displaying information of Interface Element in the Property Window has been fixed.

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-2006-11-23 <Mesh-Bug Fix> An error in calculating Twist Angle for Hexa Element has been fixed. -2006-12-06 <Mesh-Bug Fix> An error in copying Interface elements using Transform Mesh has been fixed. -2006-12-07 <Mesh-Bug Fix> An error in copying Excel Spreadsheet into a table has been fixed. -2006-12-12<Post-Bug Fix> An error in displaying probe results with different result components has been fixed. -2006-12-15 <Mesh-Bug Fix> An error in merging nodes of Interface Element has been fixed. -2006-12-16 <Mesh-Bug Fix> Interface element generation using From Beam/Plate is fixed to perform when elements have feature angle higher than 90 degrees. -2006-12-16 <Mesh-Bug Fix> An error in generating interface element between Plane and Solid has been fixed.

-2006-12-21 <Mesh-Bug Fix> An error in aligning nodes in WCS Z-direction has been fixed. -2006-12-27 <Geom-Bug Fix> Normal direction problem in 2D Project has been fixed. -2007-01-11 <Mesh-Bug Fix> An error with Work Mesh Set has been fixed. -2007-01-11 <Mesh-Bug Fix> A seeding error in using Reassign/Unseed Only option in Match Edge Seed has been fixed.

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