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ANSYS v14 Update Seminar

2

V14 Update Seminar Agenda.

8:30 Introduction • Welcome Andy Hughes to CAE Associates!

8:45 Geometry Interfaces

9:15 Meshing • Structural

• Fluid

10:00 Break

10:15 Mechanical Updates • Shell body cyclic symmetry

• Contact

• External Data Mapping

• Named Selection Tools

• FE model exposure

• Postprocessing

• Design Assessment

• Linear Dynamics

• Rigid Body Dynamics

• Explicit Dynamics

11:30 Parametric Modeling

12:00 Lunch

1:00 ANSYS CFD

2:15 Fluid Structure Interaction

2:30 Break

2:45 High Performance Computing

3:00 Vertical Applications • nCode Design Life

• ANSYS Composite Prep/post

• Engineering Knowledge Manager

4:00 Mechanical APDL • Contact

• 3D rezoning

• Dynamics

• Materials and Fracture

• Radiation

• Documentation



High Performance Computing

4

Remote Solve Manager (RSM)

Expanded Solver Support

— Full support for Mechanical and

Mechanical APDL

— More complete support for Fluent

and CFX

— Supports Serial, Local Parallel,

and Distributed Parallel processing

Update Design Points in parallel

— Send entire Design Point to

remote machine or just the

solution phase

— Submit Design Point updates from

DesignXplorer

5

Using RSM in WB

In Mechanical, you can set up a solve

process to submit jobs to RSM in Tools

> Solve Process Settings.

— Click ―Add Remote‖ to specify a name

for the Remote Solve Process

— Specify localhost as the Solve Manager

and a Queue to submit to

Now, when you’re ready to solve, click

on the little arrow next to the yellow

thunderstorms in Mechanical

— Clicking on ―Cluster1‖ will send the job

to the queue that was previously set up.

You can monitor the run in RSM and

download the results when it’s finished.

6

Submitting Design Points to RSM

In this example, I have a Static Structural analysis that has parametric

loads that I want to explore. I set up everything in the analysis and make

the following changes from the project page:

In the properties of the solution cell, change the ―Update Option‖ to

―Submit to Remote Solve Manager‖ and select the Solve Process Setting

that you had previously set up:

7

Submitting Design Points to RSM

In the properties of the Parameter Set, set Update Option to ―Run in

Foreground‖

This will read in the design point info; update the geometry, mesh, and

solver input file; then send the input file to the queue to be solved. Once

the 1st design point is out and running, WB will move on to generating the

solver input file for design point 2 and send it out.

Multiple design points can be solved simultaneously!

8

High Performance Computing

MPI Software Choices - Platform MPI and Intel MPI

— HP-MPI no longer an option

— Note for v13 Mechanical users who wish to continue use of HP-MPI: Be sure to

run the compatibility step during the installation instructions

DANSYS can now be used with GPU’s

— Limit of 1 GPU per compute node

Added support for the Quadro 6000 series GPU’s

2.1 MDOF,

Nonlinear

Structural

Analysis

using the

Distributed

Sparse

Solver

9

FEA Benchmark Problem

Bolted Flange with O-Ring

Nonlinear material properties

(Hyperelastic O-Ring)

Large Deformation

Nonlinear Contact

1 Million Degrees of Freedom

ANSYS 14

10

DHCAD5650 High End Workstation

SuperMicro 4U Tower Black SATA 5.25

Bays 8 Hotswap EATX3 800W RPS

Dual Hex Core (12 cores total)

— Intel® XEON 5650 2.66GHz Processors

24 GB RAM

— (4) 6GB (3 x 2GB) – 1333MHz

DDR3/PC3-10600 – Non-ECC – DDR3

SDRAM – 240-Pin DIMM

Four 300GB Toshiba SAS 15,000 RPM

16MB 3.5IN drives in RAID 0.

One 500GB SATA Hard Drive for the

Operating System

Nvidia Quadro FX 1800 Video Card

LG DVD/RW

11

FEA Benchmark Performance

0

1

2

3

4

5

6

0 2 4 6 8 10 12 14

Solv

er

Spe

ed

Up

# Cores

Single Machine - v14

SPARSE

DSPARSE

12

FEA Benchmark Performance - GPU

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7 8 9

Solv

er

Spe

ed

Up

# Cores

Single Machine - v14

DSPARSE - NO GPU

DSPARSE - WITH GPU

13

CFX Benchmark Problem

Flow through a complicated grille

15 Million Elements

3-D, Steady State, Incompressible Flow

k-ω Turbulence Model

14

CFX Benchmark Performance

0

1

2

3

4

5

6

7

8

9

0 2 4 6 8 10 12 14

Solv

er

Spp

ed

Up

# Cores

CFX Parallel Performance

CFX1



nCode

16

ANSYS nCode DesignLife

ANSYS nCode DesignLife is a Windows based CAE durability software

product developed by HBM and data integrated into the ANSYS

Workbench platform (WB).

— Finite element (FE) based CAE fatigue tool.

• Performs fatigue evaluation using FE results (e.g., ANSYS .rst file).

— Seamlessly integrated into WB platform.

• Easy communication with other ANSYS Mechanical products.

• Predefined WB analysis systems.

• WB file management.

• Uses Engineering Data.

— Industry leading CAE durability software product.

— Full access to standalone version.

• Standalone version is not integrated into WB.

17

ANSYS nCode DesignLife

Mechanical

18

Why Assess Fatigue?

Majority of structural components are subjected to fluctuating or cyclic

loading.

— Fatigue is the initiation and/or growth of a crack under cyclic loading.

Fatigue failures occur at stress levels insufficient to cause failure in a

single application.

Estimated 95% of all structural failures are caused by fatigue.

Difficult to detect progressive deterioration during fatigue process.

— Damage is cumulative and unrecoverable.

— Catastrophic failures can occur without warning.

19

nCode Capabilities

ANSYS nCode DesignLife software delivers modern, industry-proven

fatigue capabilities. You can simulate all types of exposure to damage

from fatigue, including:

— Stress life (SN) for high-cycle fatigue

— Strain life (EN) for low- and high-cycle fatigue

— Crack growth

— Safety factor (Dang Van) for predicting endurance limit under complex loadings

— Weld analysis for spot and seam welds

— Enhanced vibration analysis including PSD

— Hybrid loading to combine loads (constant, transient, time series, etc.)

20

nCode v14 Updates

The latest FE results files supported include:

— ansys rst 14.0

— abaqus fil 6.10-1

— abaqus odb 6.10-1

— dyna d3plot 971

Named selections in Mechanical are now converted into user groups in

nCode. There is also a new tutorial on this feature.

Existing results and property settings are now tracked to determine

whether a re-analysis is required.

— Previously, nCode re-solved any time you re-entered from Workbench.

Added a button to enable/disable the material import from Workbench.

— Previously, if you entered nCode through Workbench, you could not change

the material assignment without significant effort/changes to the process.



ACP (ANSYS Composite

Prep/Post)

22

Layered Sections in WB

Mechanical now allows the definition of a layered section for surface

bodies.

The ―Layered Section‖ must be assigned to a body.

23

Layered Sections in WB

Section layup is defined in the Worksheet:

Right click to insert a new layer:

24

Composites Lay-Ups

While Mechanical offers some capability for modeling a layup, a

coordinate system identifying the inplane directions must exist.

For complicated parts this is not always easy.

ACP – ANSYS Composite Pre/Post is a new product that greatly simplifies

the modeling and post-processing of composite elements.

25

ACP Background

ANSYS Composite PrepPost is an add-on module to existing structural

solver licenses (Professional and above) dedicated to the modeling of

layered composite structures.

First introduced in v12 it has gone through many updates and now

incorporates seamlessly with Workbench at v14.0

26

Typical ACP Usage

A shell element model is developed in Mechanical

— Meshing shell geometry, applying loads and boundary conditions.

— Can be in ANSYS Mechanical or Mechanical APDL

— Define materials (engineering data, or APDL)

Import the models in ANSYS Composite PrepPost

— Define Composite Fabrics:

• Fabric: a material and a thickness

• Laminate: an assembly of fabrics (with orientations)

• Sublaminates: an assembly of fabrics and laminates (with orientations)

— Define the element orientation (so as to properly orient materials)

— Define the ply sequence for groups of elements (usually corresponding to faces of the geometry)

Solve the model - computed by the standard ANSYS solver, in batch mode.

Post-process the results in ACP: deformations, thicknesses and failure criteria

27

Incorporation into WB Architecture

Starting with v14.0 ACP is incorporated directly into the WB architecture.

Import/Generate

surface

geometry

Define

composite

material

properties

Generate

Shell Mesh Set-up composite

material fabric

definitions, element

orientations, ply layup,

etc

28

Composite Materials

In Engineering Data, there is now a

composite materials library.

Material does not need to be assigned to

bodies in Mechanical. Material

assignment is done in ACP.

All materials in Engineering Data are

brought into ACP.

Show Libraries

29

Starting ACP from WB

Once shell mesh is generated and materials defined, ACP can be started

by right click: Edit…

30

Solving and Post-processing

Once the model is setup in APC(Pre) it can be linked to whatever type of

analyses you need to solve:

Then connect ACP(Post) to the Solution of that analysis.

31

ACP Modeling Capabilities

Multiple oriented element sets allow for multi-laminate build-up.

32

Parametric Modeling of Composites

New integration of ACP in Workbench allows for parametric modeling of

ply geometry.

Example below shows parametric changes of doubler width shown in red.

33

Efficient post-processing of composite-specific results quantities.

New Sampling Element post-processing.

— Plot worst case failure criteria over all layers.

— Pick element and see stress/strain and failure through the thickness

Post-processing of Composite Results

34


Make thru-thickness stress plots and account for interlaminar normal

stresses with shells.

— Traditional shell approaches can not account for interlaminar normal stress

(shown in blue curve)

— ANSYS Composite PrepPost can predict these base on the work of Roos,

Kress, & Ermanni

Thru-Thickness ILS & ILN Stress Plots – Solids

Thru-Thickness ILS & ILN Stress Plots – Shells

Critical Stresses in Bend

35


Sandwich Construction Post-processing.

— Wrinkling

• Local buckling of a face sheet under compression

• Failure indicator available using shell modeling of sandwich

— Core Failure

• Local failure of core in shear or tensile loading

• Failure indicator available using shell modeling of sandwich

36

ACP Analysis Integration

Explicit dynamic model uses same composite setup

— Bird-Strike, Drop Test, Crash and Impact, etc.

— Simple setup for Eulerian mesh

37

Advanced ACP Capabilities

Fiber orientation prediction and modification.

— Use internal ACP draping simulation to compute orientation changes due to

geometry curvature, develop flat pattern.

— Interface with Vistagy’s FiberSim.

— Modify the fiber orientation to something that is actually observed on the

manufacturing floor through alignment with local rosettes.

38


3D Solid Modeling:

— If a composite part is thick and bulky a shell mesh may not be sufficient to

predict accurate results.

— One of ACP(Pre) strengths is that the 2D shell mesh can be extruded into a 3D

solid model.

— CAD support: STEP and IGES geometries can be imported to define thick

cores or use as guides for 3D extrusions.

— R14 Improved solid model extrusion, transitioning, and drop-off capabilities

39


Even more…

— Map composite thickness and angles through table look-up.

— Build complex assemblies including contact.

— Customize layups using scripts and tables (Filament winding)

— Multiple solid models can be combined through links to MAPDL.

— 2-Way FSI with composites



ANSYS EKM

41

What is EKM?

Engineering Knowledge Manager

— ANSYS EKM is a simulation process and data management (SPDM) software

system that allows engineers at all levels of an organization to effectively

manage the data and processes created through their design, simulation, and

analysis activities.

— It facilitates reuse of historical information and capturing of engineering

knowledge and best practices that can help reduce your organization's future

development and training costs and make better use of resources. These

savings can ultimately reduce a product's time-to-market.

— EKM is tightly-integrated with ANSYS simulation products, including ANSYS

Workbench, Mechanical APDL, FLUENT, CFX, POLYFLOW, HFSS,

Simplorer, and Ansoft Designer, and can also be integrated with other third-

party simulation products such as Abaqus and Nastran.

42

EKM Summary

ANSYS EKM's comprehensive system of tools can be used to:

— Provide central storage of CAE simulation data.

— Capture, manage, and improve simulation processes.

— Search and retrieve simulation data.

— Control access (security, version control, check-in/out) to your simulation

processes and engineering data.

— Execute simulation jobs using RSM (Remote Solution Manager) from within

EKM.

— Manage object lifecycles through signoff processes.

— Customize a data repository to fit the particular needs of a simulation team.

— Track the actions and decisions taken during simulation process for regulatory

compliance.

43

EKM Features

44

v14 Enhancements

Product Installation and Setup: An EKM server can now be installed and

set up on a local machine for a single user, or on shared hardware for

multiple users using the ANSYS 14.0 installation media.

— EKM Individual Server: This setup type allows an EKM server to be set up for

an individual user on their own machine. In this single-user mode, a user can

access their ―private‖ repository on their individual server, as well as having

access to the full capabilities of EKM.

— EKM Shared Server: This setup type allows an EKM server to be set up on a

shared device that can be accessed by multiple users in a collaborative mode.

Multiple users can access a shared repository in their LAN (Local Area

Network) or across a WAN (Wide Area Network).

45

v14 Enhancements

Integration with ANSYS Workbench:

— When you install ANSYS Workbench, the EKM Desktop client is automatically installed on your hardware.

— You can save your current Workbench project directly to a selected repository, and search for a Workbench project and open it from a selected repository.

— After updating the local copy of your Workbench project, you can then send changes to the copy of the project that resides in the EKM repository. Other users who have updated the same Workbench project can get your changes in order to access the most-up-to-date version.

— Tighter integration with Workbench facilitates collaboration with ongoing projects and allows multiple users to leverage on the work that is being done by their colleagues.

ANSYS Workbench Project Representation in EKM:

— When a Workbench project is saved as a Workbench Project Archive File type (with .wbpz extension), making it easier to manage and act on the project as a single object in EKM.

— Project-level metadata is extracted and an extensive Workbench Project Report is auto-generated that summarizes component systems and all aspects of the Workbench project. The data can be used to display, identify, search, and reuse Workbench projects

46

v14 Enhancements

Migration from EKM Individual to Shared Repository:

— You can use the export and import features of EKM when you want to migrate data from one repository to another.

— You can either migrate a complete workspace or just a subset.

• For example, you can use this to migrate all of the data and configuration contained in an individual server to a new workspace in a shared server.

EKM Desktop Enhancements:

— The "local" repository feature has been replaced by the EKM individual server.

— File transfers have been made more robust.

— Advanced search and reporting features have also been improved for this release.

Record and Replay of Journals:

— You can now create journal script files by recording your interactive actions in the EKM web client.

Audit Trail:

— Feature available in the Process Player that can be used to can track the decisions and actions that are made during a workflow process for work items that have been completed.

— This helps in fulfilling audit needs for regulatory compliance.

47

v14 Enhancements

Licensing Enhancements:

— In Release 14.0, the licensing framework for EKM has been simplified.

— Now, you will only need an EKM individual user license key or an EKM shared user license key to access EKM, based on the type of server you are accessing.

Usability Enhancements: Numerous other usability enhancements have been made to EKM. These include:

— Search results can be displayed in a Tree view, and search snippets for the results can also be displayed

— Default metadata and report extraction methods can be extended by the use of additional user-defined extractors

— A user-defined cleanup policy for deleted items in the Recycle Bin can be specified

— The ability to execute a scriptable action as a scheduled task has been added

— A ―private‖ search query for any user can be added to the built-in Systems/Public Shared Queries folder so that it can be accessed by all users

— A ―Quick Compare‖ report option now allows you to compare multiple files using default settings with a single click; improvements to customized comparison report formats have also been made



Mechanical APDL



Contact Enhancements

50

Contact Stabilization Damping

Small gaps (open contact) in a static analysis can lead to convergence

issues

The new contact-stabilization damping feature provides a means to avoid

these problems.

Stabilization damping applies a restoring pressure (or force for point to

point contacts):

— Pstab = C * Vel

— Damping (C) is specified using the real constants FDMN and FDMT. Positive

numbers define contact damping ―scaling factors‖ in the contact normal and

tangential directions.

— Default damping is calculated internally based on:

• Contact stiffness

• Pinball radius

• Gap distance

• Number of substeps

• Size of time increment for the current substep

— Use a negative number to specify actual damping value

— Velocity is the relative motion between contact and target / time increment.

51

Stabilization Example

Force applied to an unconstrained body with open contact in static

analysis:

52

Stabilization Damping

The Stabilization Damping is active only if:

— Contact status is ―Near Open‖

• Be sure to adjust pinball if necessary

— Real constant FDMN and/or FDMT are specified.

— All contacts had ―Open‖ status in previous substep and it is first load step.

— KEYOPT(15) controls these settings:

• 0 -- Damping is activated only in the first load step (default).

• 1 -- Deactivate automatic damping.

• 2 -- Damping is activated for all load steps.

• 3 -- Damping is activated at all times regardless of the contact status of previous

substeps.

53

Stabilization Damping

Damping is deactivated when contact is closed

Damping force automatically drops to 0 when there is no relative

displacement. Velocity = 0

Artificial energy introduced due to damping force can be plotted using

element table AENE quantity, or PRENERGY command.

54

Surface Projection Based Contact

Surface-projection-based contact, introduced in v13.0, enforces contact

constraints on an overlapping region of contact and target surfaces rather

than on individual contact nodes or Gauss points

— This significantly improves the accuracy of contact results and provides

smoother stress distributions for the case of dissimilar meshes at the contact

interface.

— The surface-projection-based contact method is implemented by setting

KEYOPT(4) = 3 on the contact element.

This has been extended to 2D contact and to MPC based contact in v14.

55

Surface Projection Based Contact

2D Model – 2 bars, dissimilar meshes, MPC bonded contact under tensile

load:

Without surface projection based contact With surface projection based contact



Rezoning

57

Rezoning

Rezoning is a procedure for remeshing the model part way through an

analysis.

— It helps in models where parts deform severely such as manufacturing

(stamping, rolling, extrusion, etc.)

— Helps with convergence and accuracy.

Before rezoning After rezoning

58

Rezoning

Version 14 adds support for rezoning of 3D Models.

Generate a new mesh from the updated geometry.

— UPCOORD: Update mesh to deformed configuration

— CDWRITE out the updated mesh and read the .cdb file into FEModeler.

— Use FEModeler to generate geometry from the deformed mesh

• Generate a new mesh in Workbench

• Write out a Parasolid file and read it back into a new MAPDL session.

— Or any other method for generating an updated mesh for the deformed

geometry.

Displacements, stresses, and strains are imported and mapped onto the

new mesh from the restart files generated during the original run.

59

Rezoning

Rezoning Commands:

— RESCONTROL – Define restart points. Restart files are needed at the

rezoning step.

— REZONE – Specify the load step and substep at which you want rezoning to

occur

— REMESH,START – Initiate the remeshing phase

— REMESH,READ (read a new mesh from a .cdb file)

— REMESH,FINISH – End the remeshing phase and transfer B.C.s and loads to

the new mesh

— MAPSOLVE – Map displacements, stresses, and strains onto the new mesh

from the rezoning step (specified in the REZONE command)

• This data is obtained from the restart file for this step

• Additional substeps are automatically added to obtain equilibrium

— SOLVE – Proceed with the solution

60

Rezoning

Example: Hot-Rolling Analysis with 3-D

Rezoning

— Solution fails to converge with the

original mesh

— Rezoning allows solution to proceed to

completion

Original mesh at

56% plastic strain

Rezoned mesh at

56% plastic strain

61

Rezoning Enhancements

More nonlinear material models can now be used with rezoning

— The following TB options are available:

• KinH, DP, Plastic, (KinH, Miso), Creep, Chaboche, Rate, Hill, Prony, Shift, Cast,

CDM, Ahyper, BB

— The following user defined materials are available:

• UserMat, UserCreep and UserHyper

• All of the state variables are mapped automatically to the new integration points

during rezoning



Dynamics

63

Linear Dynamics

Damping: material - dependent damping options changed

— MP,,ALPD – for material - dependent mass damping

— MP,,BETD – for material - dependent stiffness damping

— MP,,DMPR – for material - dependent damping ratio (replaces obsolete

MP,DAMP)

Natural frequencies and mode shapes from a modal analysis using Linear

Perturbation can be used in downstream mode superposition harmonic ,

transient, PSD, and response spectrum analyses.

If nodal temperatures are applied in a modal or harmonic response

analysis (for evaluation of temperature depended material properties) ,

the new THEXPAND command allows the thermal loads to be ignored.

— Previously had to zero out coefficients of thermal expansion.

64

Linear Dynamics

Spectrum Analysis

— Mass proportional damping (ALPHAD) is supported in response spectrum and

PSD analysis.

— RESP command now also allows acceleration time-history input in order to

generate response spectra.

• Prior versions were limited to displacement input.

— Maximum number of input tables in a MPRS and PSD analysis now 200.

Maximum number of participation factor calculations (PFACT) now 300.

— Spectrum Combination – option to sum both stiffness and inertial forces.

• Default is static forces only

65

Acoustics

Many New Acoustics Additions

— Check Release Notes and Section II of the MAPDL Fluids Analysis Guide

for more details.

— Some examples:

• Simulate temperature-dependent nonuniform ideal gas

• Simulate the propagation of sound in viscous medium.

• Apply various analytic sources (plane wave, monopole/pulsating sphere, dipole,

bare loudspeaker, and back-enclosed loudspeaker ).

• Apply the Robin boundary condition (finite acoustic impedance) to the exterior

surface of model for radiation or scattering analysis.

• Define a sloshing surface.

• Plot and print near- and far-field pressure, sound pressure level, directivity, sound

power level, far-field scattered pressure, and target strength values.



Material and Fracture

Enhancements in V14



VCCT Enhancements

68

VCCT-Based Crack Growth Simulation V14 includes a new approach to crack growth simulation. The method is

based on the virtual crack closure technique (VCCT) with interface

elements to model the crack growth.

The method is intended for interfacial delamination of laminate

composites.

— Also applicable to crack growth simulation in homogeneous material.

A number of fracture criteria are available, including critical energy-release

rate, linear, bilinear, B-K, modified B-K (Reeder), power law, and user-

defined.

69

Delamination Techniques

Virtual crack closure technique (VCCT) is a method to

simulate the behavior of delamination of layers in a

composite material:

— Uses special interface elements along a pre-defined

interface to model the delamination of cracks.

VCCT calculates energy-release rate, with the assumption

that the energy needed to separate a surface is the same

as the energy needed to close the same surface.

— Strengths:

• Mature fracture mechanics-based technique with large body of

work.

• The growth criteria is the energy release rate, G.

— Weaknesses:

• Assumptions about cracks must be made (number, location,

size).

70

VCCT: Energy Release Rate Calculation

The ANSYS procedure for calculating the VCCT energy release rate uses

the CINT command.

— Similar to J-Integral calculation in ANSYS.

CINT command used to define:

— Crack location: crack tip (2D) or crack front (3D) node component.

— Crack extension direction: by identifying node on the open side of crack or a

local coordinate system axis.

— Option to indicate that the crack runs along a symmetry plane.

This procedure is used to calculate the energy release rate for a given

crack of a specific length and position.

71

VCCT Crack Growth in V14

An automated crack growth simulation procedure, using the VCCT energy

release rate calculation, is available in ANSYS.

Assumptions:

— Available with lower order current technology elements PLANE182 and

SOLID185.

— Crack growth along predefined path – new command CGROW.

— The path is defined with interface elements INTER202 and INTER205.

— Static analysis.

— Linear elastic material.

— Isotropic, orthotropic or anisotropic materials can be used.

— Several fracture criteria are available including a user-defined option.

— Multiple cracks are allowed.

72

VCCT Crack Growth

Example case.

— Double cantilever beam, separating along interface.

• INTER202 elements define interface (CZMESH command).

— Linear fracture criterion defined based on critical energy release rates.

• Undocumented TB,CGCR option.

— Crack growth automated with CGROW command.

• Defines crack path, fracture criterion, time steps.

Interface

73

VCCT Crack Growth

There are 7 fracture criteria that can be defined using the TB,CGCR

material definition option.

— All criteria are based on some definition of the critical energy release rate Gc.

— For example, the linear fracture criterion:

• GTC = critical energy release rate.

Fracture occurs when:

IIIIIITC

T

T GGGGG

Gf

1f

74

VCCT Crack Growth

Animation of displacement.

75

VCCT Crack Growth

Force vs. deflection of delamination.



Cohesive Zone Enhancements

77

Cohesive Zone Enhancements

A new bilinear option (TB,CZM,,,,BILI) is available for modeling interface

delamination using interface elements (INTER202 through INTER205)

with a cohesive zone material (CZM) model.

The new CZM model option uses bilinear traction-separation laws.

Previously this type of debonding was available for CZM using contact

elements, in v14 it is now available for interface elements.

../ans_cmd/Hlp_C_TB.html

../ans_elem/Hlp_E_INTER202.html

../ans_elem/Hlp_E_INTER205.html



Progressive Damage of Fiber-Reinforced

Composites

79

Progressive Damage

Damage initiation and propagation in fiber-reinforced composites can now

be simulated using a new, built-in, nonlinear solution procedure in ANSYS

V14.

— Different from the existing post-processing failure analysis in ANSYS.

Technique requires definition of linear elastic orthotropic material

properties, and three material models:

— Damage initiation criteria: TB,DMGI

— Damage evolution law: TB,DMGE

— Material strength limits: TB,FCLI

Must be input via commands, no GUI input.

80

Damage Initiation

Damage initiation defines the criterion type for determining the onset of

material damage (TB,DMGI).

— Can select a separate criterion for tensile and compressive failure, and for both

fiber and matrix.

— Criteria include:

• Maximum strain

• Maximum stress

• Puck

• Hashin

• LaRc03

• LaRc04

• User can also define up to 9 user-defined criteria.

81

Damage Evolution

Damage evolution defines how the material degrades following the

initiation of damage (TB,DMGE).

— The only evolution law currently available in version 14 is instant stiffness

reduction.

— The input to this law is the reduction factors for tensile and compressive

stiffness, in both tension and compression.

— The values can range between 0 (no damage) and 1 (complete damage).

82

Material Strength Limits

This input is used to define the maximum stresses or strains that a

material can sustain before damage occurs (TB,FCLI).

— The values to be input are based on the damage initiation criterion selected.

83

Damage Test Case

Plate with hole under tension load.

— 2D plane stress formulation.

— Orthotropic material properties.

— Use maximum stress damage criterion in all directions.

— Assume stiffness at damage is instantly reduced by 50% for all directions.

— Far-field stress = 4,000 psi.

— Damage initiation stress = 10,000 psi in fiber direction (x), 8,000 psi in matrix

direction (y).

84

Damage Test Case

Comparison of x-displacement for undamaged and damaged models at full

load (same contour range):

Undamaged Damaged

Max deflection = 0.00174 Max deflection = 0.00187

85

Damage Test Case

Comparison of x-stress for undamaged and damaged models at full load

(same contour range):

Undamaged Damaged

Max stress = 31.1 ksi Max stress = 24.5 ksi

86

Damage Test Case

Stress-strain behavior in fiber (x) direction, comparing no damage and

damage cases, at critical location at edge of hole:



Material Enhancements in

V14

88

New Mircroplane Material (Concrete, etc)

Why use the Microplane Material Model?

— 2d (plane stain, axisymmetric) & 3d lower

order and higher order elements

— Works with reinforcement elements

(264,265)

— General damage based material law with

residual strength after ―cracking‖ &

―crushing‖

Why stay with the Solid65 Element?

— Easy concrete specific input (tensile

strength, compressive strength etc.)

— Plotting of smeared cracking and crushing

on an integration point level

— Historical benchmarking with physical

tests and existing literature data

— 3d brick modeling only

— No crushing residual stiffness required

89

Shape Memory Alloy Enhancements

Two Material Options for Nitinol (nickel titanium (Ni-Ti) alloy)

— Superelastic Material Model (previous versions)

• Large Deformation without permanent deformation

— Shape Memory Effect (new for V14)

• Thermo-mechanical model for stress induced phase transformation

• Memory effect – permanent deformations

• Austenite & Martensite Modulus Input

Elements supported:

— ―180 series‖ plane strain, axisymmetric, solid, and solid-shell elements

Cycling imposed displacements



Thermal/Radiation Enhancements

91

Radiation Enhancements

New command VFSM

Adjusts the view factor matrix to ensure good energy balance

— VFSM options:

• 0 — The view factor matrix values are not adjusted (default).

• 1 — The view factor matrix values are adjusted so that the row sum equals 1.0.

• 2 — The view factor matrix values are adjusted so that the row sum equals 1.0 and

the reciprocity relationship is also satisfied.

• 3 — The view factor matrix values are adjusted so that only the reciprocity

relationship is satisfied.

• 4 — The view factor matrix values are adjusted so that the original row sum is

maintained and the reciprocity relationship is satisfied.

— Options 1 & 2 are for a perfect (closed) enclosures. Sum of view factors = 1

— Options 3 & 4 are for open enclosures. Sum of view factors < 1.

— Options 2 & 4 require an iterative solution to adjust the view factors.

— Reciprocity: AiFij = AjFji

92

Radiation Enhancements

View factor calculation now done in parallel when running distributed

ANSYS if calculated by SOLVE command.

Calculation is serial of performed by VFOPT,NEW command.

Radiosity solution now runs in distributed mode with new Jacobi iterative

solver

— RADOPT,,,2

— Only valid for 3D models, reverts to Gauss-Seidel iterative solver if 2D model.



Documentation Updates

99

New Documentation Guides

Material Reference

— This reference provides a single, convenient resource for information about the

available material models, linear and nonlinear material properties, material

data tables, material model combinations, explicit dynamics materials, element

support for material models, and other important information. Expect to see

ongoing improvements in subsequent releases.

Parallel Processing Guide

— All topics related to parallel processing have been moved into the new Parallel

Processing Guide. The guide includes the following primary topics: shared

memory parallel, distributed memory parallel (Distributed ANSYS), and GPU

acceleration. All of these topics had been previously located in various other

guides.

../ans_dan/dantoc.html

../ans_dan/dantoc.html

100

Technology Demonstration Guide

Introduced in v12, the Technology Demonstration Guide provides detailed

APDL examples of some advanced analysis techniques.

101

Technology Demonstration Guide

At v14 several new examples were added to the Technology

Demonstration Guide:

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