ABAQUS 2018 Technical Update

ABAQUS 2018 TECHNICAL UPDATE
March 19th, 2018
1400 Broadfield Blvd. Suite 325, Houston TX 77084
Phone : +1 (832) 301-0881
www.viascorp.com
Arindam Chakraborty
VP-Advanced Engineering
achakraborty@viascorp.com
Nishant Kumar
Senior Simulation Engineer
nkumar@viascorp.com
Ali Can Solak
Managing Partner, BD and Software Sales
asolak@viascorp.com

© 2018 Virtual Integrated Analytics Solutions Inc. 2
Agenda
▪ Company Overview and Value Proposition
▪ Abaqus 2018 Update
▪ Q&A

VIAS Overview
Engineering
Consultancy
Training
Automation &
Customization
Software
© 2018 Virtual Integrated Analytics Solutions Inc.
• Multiple Industry Experience – Energy and Process, Life
Science, Industrial Equipment, Transportation and Mobility,
Hi-tech, Aerospace, etc.
• Presence in Houston, Chicago, Cincinnati, San Francisco,
Detroit
• Team consists of Ph.D.s and Masters in Solid Mechanics,
Fluid Mechanics, Materials and Corrosion, Numerical
Analysis, Statistics; Optimization and Reliability
• Solution partner of Dassault Systèmes products – SIMULIA
(Abaqus, Isight, fe-safe, Tosca), CATIA, DELMIA,
3DEXPERIENCE
• Provides Virtual Design Experience through Collaboration
and Data Analytics – Provides Automation and Customization
• Provide 3D Printing and AM Simulation Services
44

Technical Capabilities
© 2018 Virtual Integrated Analytics Solutions Inc. 55
Component Design and
Validation using Simulation
FEA based Fracture /
Damage Mechanics / ECA
Design Optimization and
Reliability
Structural Analysis /
Vibration Assessment
Electromagnetic Systems
(Design, Simulation, and
Optimization)
Multi-physics Simulations
(CFD, Flow Analysis, Thermal
Analysis)
S-N and e-N based Fatigue
Analysis (varying
temperatures)
Composites Modelling and
Analysis
Simulation Automation
Digital Mock – Up
Development and Systems
Engineering (Electrical
Cabling / Piping / Ducting)

Our Value Proposition as A Software Solution Partner
We are committed to every client’s success through technical excellence and innovation
We have domain knowledge in FEA and expertise in multiple industry applications
We can also review your existing simulation workflow/processes and provide you a
feedback if it require any enhancement for speed and usability
We provide customized, and standard (introductory and advanced) trainings – in-
house, onsite, and online
We offer software development services for Abaqus including user subroutines, user
elements, and python scripts, allowing pre- and post- processing features/calculations

Training
As authorized education partner of Dassault Systèmes, we offer Abaqus SIMULIA training courses either in
house or at our client's facility.
Please visit https://www.viascorp.com/course-schedule/ to see our full course portfolio.
Sample courses include but not limited to Introduction to Abaqus, Introduction to Abaqus CAE, Introduction to
Abaqus Scripting, Introduction to Abaqus CFD, Abaqus for Offshore Analysis, Modeling Fracture and Failure
with Abaqus, Introduction to Isight, Introduction to fe-Safe.

Open House Days
We are happy to offer the free Abaqus Support
Open House Days at our office on first Friday of
each month.
This is an excellent way to learn about Abaqus,
Isight, fe-Safe, and Tosca capabilities from our in-
house experts. During the Open House, VIAS
provides short trainings free of charge on various
topics of interest like convergence, contacts,
explicit, implicit dynamics.
You can also bring your general simulation
related problems and we can help you to
troubleshoot them. We can also suggest the best
methodology to speed up your Abaqus analysis.

When creating a node set,
note the new option to use the
“unsorted” set procedure
Add nodes:
• Individually – Pick one by one in
order
• Along geometric edges in order
• By free picking (usual drag,
angle, edge, set, etc.)
• By entering labels manually in
the table
Use a Python expression to order
part or all of the set according to
parameters (X, Y, Z, label)
Unsorted Node Sets Support

• Intuitive table defines the set contents
• Select one or more rows, and RMB menu allows
moving blocks up and down, clear data,
expand/combine rows, etc.
• Insert before/after current row, or directly modify
row
• See nodes in rows highlighted as each row is
selected
➢ Type in an expression to
quickly sort selected row(s)
using X, Y, Z, (R, Th, P) or
Label
Unsorted Node Sets Support

Improved Equation Constraint:
❖ Prior to Abaqus/CAE 2018, each referenced set after the
first must contain only a single node
❖ Restriction is now removed – Subsequent sets can contain
multiple nodes as long as all sets contain an equal number
of nodes
Create Node List Path
from Unsorted Node Set
in /Viewer
Also: Create XY Data from Path directly
from an unsorted node set
Unsorted Node Sets – Related Enhancements

Currently, applying bolt loads in CAE is frustrating, particularly if
there are many similar bolts requiring loads. This enhancement
addresses the usability issues.
Now you can specify the bolt shank surface +
cut position
• Automatically partitions cylindrical surface
and selects new interior surface
• May even be done on a dependent
instance to partition the underlying part
Improved Bolt Loading Process

❖ No longer requires user to select a
bolt axis
o Default is normal to interior surface
❖ When manually selecting an axis,
user is given the option to flip the
direction right in the pick step

❖ Write pre-tension section at the part level
o Optionally create pre-tension section once and
it is effectively applied to all similar instances in
the assembly
o Single bolt load, but *CLOAD appears for each
instance in INP
o Also avoids need to request history/field output
separately for many similar bolt loads

Users can now specify Field as a
predefined field, similar to Temperature
Options:
• Direct specification
• From ODB
• Analytical Field
• User Subroutine
Support* Field

Direct specification options:
• Constant through region
• Gradient through beam section
• Defined at shell/beam field points
From ODB: Specify start step/inc + end
step/inc
What about Initial Step? → *INITIAL
CONDITION, TYPE=FIELD
• No user subroutine specification
• No Amplitude option for Direct
specification or Analytical Field
specification
Support* Field

❖ Prior to the 2018 version, view cut
based free bodies are disabled in
/Viewer when solid composite
elements are present in the view cut
❖ Now CAE calculates an average
stress variable from solid composite
stress variables, extrapolates to the
nodes, and proceeds as for a
homogeneous solid.
View Cut-based Free Body Forces for Composite
Solids

C3D5 Finite Element Approximation
▪ Isoparametric 5-node pyramid element;
▪ Five integration points without hourglass control;
▪ Identical element formulation as used in Standard.
C3D4H Finite Element Approximation
▪ Based on the weight of average nodal strains and element
strains;
▪ The element formulation is different from that used in Standard;
▪ Won’t lock for incompressible materials (plasticity and
hyperelasticity)
Linear Pyramid and Hybrid Tetrahedron Elements

• Elements C3D5 and C3D4H support all of the loadings, material
behaviors, and boundary conditions supported by the existing
brick, wedge, and tetrahedral solid elements in Abaqus/Explicit.
• Import from Abaqus/Explicit to Abaqus/Explicit is supported.
• Import from Abaqus/Standard to Abaqus/Explicit or from
Abaqus/Explicit to Abaqus/Standard is NOT supported.
Linear Pyramid and Hybrid Tetrahedron Elements

Standard – C3D4H Explicit – C3D4H Explicit – C3D4
Taylor Bar with Coarse Mesh: Displacements

❑ Keyword Interface
*EULERIAN BOUNDARY, INFLOW=NONE,
OUTFLOW=NONE
❑ OUTFLOW=NONE can only be used with INFLOW=NONE
to eliminate normal component of the velocity
❑ CAE support – not yet added.
User Interface

❑ Comparison of EBC and contact (model setup)
Eulerian BC CEL contact
Forming Simulation Example

❑ Comparison of EBC and contact (final deformation)
Eulerian BC CEL contact
Note the separation
of Eulerian material
from the contact
surface, which
contributes to the
difference in the
reaction force

Enhanced Boundary Conditions for SPH
• SPH particle generation on an inlet surface
• SPH particle removal on an outlet surface
• Enforce velocity/natural BC on inlet surface
• Enforce non-reflect/pressure BC on outlet
surface

Channel flow
Enhanced Boundary Conditions for SPH

• Field filtering capabilities were extended to include principal strain
values
• Available only in Abaqus/Explicit
• Existing values MinP, IntermP, MaxP can now be used with strain
output on *FILTER. (Values “first” and “second” do not apply to
strains.)
*Filter, Name=filter_name, Invariant=( First, Second, MinP,
IntermP, MaxP )
…
*Output, Field, Filter=filter_name
*Element Output
LE, NE, E, THE
Field Output Filtering Enhancements

INTERNAL UPDATE ON CONTACT
& CONSTRAINTS FOR ABAQUS
2018

• XFEM surfaces in general contact
Developed in collaboration with ExxonMobil
URC
Abaqus/Standard
“XContact”

Potential contact scenarios for XContact surfaces
AAA
A’A’ A’ Contact stresses
developed on
crack faces
(a) (c)(b)
(a) (b)
(a) (b)
(a) (b)
Pieces may contact
each other or other
parts
Self contact

• Often can’t anticipate which interior edges
become folded
• Such as in a paper crumpling example
• Airbag analyses have mostly unfolding, but
some initially flat regions become temporarily
folded
• Nonphysical “snags” occur if these folds are not
considered for contact
• So users often specify ALL EDGES for the
“static” feature-edge criteria based on original
configuration only
• Robust and accurate
• But poor performance
• Now, can update which feature edges are
considered for contact based on current
configuration
✓ Robust and accurate
✓ Good performance
Abaqus/Explicit
Dynamic feature edge criteria

• Initially flat paper
• Perimeter edges are only initial feature
edges
• Lots of folds develop during crumpling
• Average percentage of edges active
across increments is about 35%
• Maximum percentage of edges active is
about 62% 0
20
40
60
80
100
0 25000
%
Increment #
Percentage of edges active
Paper crumpling example

Material type on one side of contact
interface
Mat
1
Mat
2
Mat
3
Mat
4
Mat
5
Mat
6
Materialtypeonothersideofcontact
interface
Mat
1
1 7 8 9 10 11
Mat
2
2 12 13 14 15
Mat
3
3 16 17 18
Mat
4
4 19 20
Mat
5
5 21
Mat
6
6
• Option to derive approximate friction coefficients from surface
properties
Example with:
• 6 materials
• 21 material
combinations
With a combinatorial rule
approach:
• User specifies friction coefficients
for 6 materials: 𝝁1 thru 𝝁6
*Surface Property Assignment,
Property=Friction
• These apply to contact between like
materials (𝝁𝑖𝑖 = 𝝁𝑖)
• Friction coefficients for contact
between different materials are
derived:
• 𝝁𝑖𝑗 = 𝒇 𝝁𝑖, 𝝁 𝑗
• E.g., 𝝁𝒊𝒋 = 𝟏. 𝟑 − 𝟎. 𝟑
𝝁𝒊
𝝁 𝒋
𝝁𝒊, where 𝝁𝒊 ≤ 𝝁𝒋
• Override as desired with pairwise
assignments
Abaqus/Explicit
Friction coefficients

1. As a contact property
2. As a surface property (with a combinatorial rule in effect)
 By default, the contact property assignment tasks precedence
 The user can reverse (defer) the precedence with:
*Friction, Coefficient Precedence=Surface Property Combination
Exception: user-assigned contact property assignment
that does not include friction would not take
precedence over a friction coefficient based on user-
assigned surface properties
If friction coefficient is specified both ways

Unsymmetric matrix input treatment in Abaqus 2018
• Advanced mechanical features such as contact friction models can introduce unsymmetry in the
finite element operators for example, in the stiffness operator (matrix). Unsymmetric matrices
can be included in the finite element model using the matrix input feature to reproduce advanced
linear behavior of the structure parts. Some analysis procedures for example, the real
eigenvalue analysis procedure require finite element operators to be symmetric, and the
imported unsymmetric matrices have to be symmetrized. Formal averaging of the matrix and its
transpose is not physical, and using this symmetrizing technique can produce incorrect
mechanical results:
• There is no universal matrix symmetrizing method for the finite element matrices. A physically
meaningful symmetric formulation associated with the unsymmetric finite element operator
should be derived based on reasonable theoretical assumptions. Such consistent formulations
are implemented in Abaqus, and both symmetric and unsymmetric operator instances can be
generated by the matrix generation analysis procedure:
STEP, UNSYMM=NO
*MATRIX GENERATE,MASS, STIFFNESS, VISCOUS DAMPING
*END STEP
*STEP, UNSYMM=YES
*MATRIX GENERATE,STIFFNESS,MASS,VISCOUS DAMPING
*END STEP*
( )1
2
T
SYM = +A A A
Matrix Input

CONTINUUM SOLID SHELL
ELEMENT (CSS8) ENHANCEMENTS

Introduced in Abaqus/Standard
2017x
• 3D continuum element for thin
structure applications
• Well-suited for composite
solids
• 3D material models
Continuum solid shell element (CSS8) enhancements

Behavior when a user-defined orientation is used with CSS8 elements:
• Abaqus 2017x: orientations were not projected onto element midsurface (as
for regular brick elements)
• Abaqus 2018x: orientations are now projected onto the element midsurface in
the initial configuration such that the local material 3-direction is normal to the
element midsurface (as for continuum shell elements)
• In geometrically nonlinear analyses, the local directions rotate with the average
material rotation at each material point, the same as for other solid elements.
• If the element undergoes significant transverse shear deformation, the local 3-
direction will no longer remain normal to the element midsurface.
• Facilitates conversion of SC8R models to CSS8
*SOLID SECTION,ELSET=elset_name,ORIENTATION=ori_name,
MATERIAL=mat_name or COMPOSITE Midsurface normal
New treatment of user-defined orientations for CSS8

User-defined orientations are now projected onto the element mid-surface
Similar to continuum shell elements
Wrapped thick cylinder
under
pressure and thermal
loading
No orientation
projection
Abaqus 2017x
Orientation projected
Abaqus 2018x
New treatment of user-defined orientations for CSS8

DC3D8R
8-node linear heat transfer brick, reduced integration, hourglass
control
• Same as DC3D8 except reduced integration – 1 instead of 8
integration points
• Uses the same integration schemes as in C3D8RT
• Applies the same hourglass control formulation as in C3D8RT
• For a benchmark analysis with 1M elements
• Element calculation time decreased by a factor 1.5 from 60 to 40 sec
• Total analysis time (10 incs) decreased from 1650 to 1250 sec
• Satisfactory accuracy
Introducing DC3D8R element

Coupled temperature-displacement gasket elements
• When running a coupled temperature-displacement analysis of a
head/engine block assembly it is currently not possible to consider the
thermal flow across the gasket from the block to head
• Temperature dofs be needed to be added to gasket elements in order
that the thermal field can be evaluated during coupled temperature-
displacement simulations
• Enhance the family of existing gasket elements to include
temperature dof at the nodes
• Thermal conductance between top and bottom surfaces defined as a
gasket/material property(by using *GAP CONDUCTANCE)
• Four 3D elements (GK3D6T, GK3D6TN, GK3D8T, and GK3D8TN)
have been created

• An improved interpolation approach has been implemented,
which ensures that unloading behavior is within the bounds
specified by the user (through the unloading curves under the
gasket thickness behavior option).
(IR-544766)
• os.environ["New_Gasket_Interp"]='1'
Verification example: Gasket element assembly –
eg38gdxf_ctd.inp:
Two layers of gasket elements are used in the
middle, and contact pairs are defined between
the gasket surfaces and solid element on the top
and bottom.
Gasket
layer
Gasket
layer
Coupled temperature-displacement gasket elements
(Continued)

Material Enhancements
• Enhanced Mean-field Multi-scale functionalities
• User-defined Thermal Material Modeling in Abaqus/Explicit
• Enhancements to Thermal Expansion Modeling
• Enhancement to Superelastic materials
• Enhancements to Structural Relaxation Model (TNM)
• Latent Heat smoothing
• Material Property and Parameter tables

AMG ITERATIVE SOLVER
ENHANCEMENTS IN ABAQUS
2018
SIMULIA R&D Structural Mechanics,
Solvers

Agenda
• Industry Challenges and 3DEXPERIENCE Industry Workflows
• Linear Equation Solvers for Big Models
• DMP Direct Sparse Solver and Iterative Solver
• Performance and Productivity Study
• SIMULIA Internal Test Models
• Turbine Blade
• Plastic Bumper
• Current Status
• What is Supported and not Supported yet?

High-dimensional scatter Bubble Graphs
• Isight 2018 has a new type of scatter plots called “Bubble
Graphs” that can represent 5-6 dimensions in a single visual
representation
• Bubble graphs can represent up to 3 additional dimensions, in
addition to x, y, z co-ordinates, by means of color, size and
glyph type
• 2D bubble graphs can represent up to 5 dimensions in a single
visual representation
• x, y and optionally, color, size and glyph type
• 3D bubble graphs can represent up to 6 dimensions in a single
visual representation
• x, y, z and optionally, color, size and glyph type

Bubble Graphs – Examples

Adaptive DOE Algorithm
• A new space filling DOE algorithm, developed by SIMULIA CTO office,
that maximizes the minimum distance to neighboring points
• Packaged as a new DOE plugin
• A unique feature of this algorithm is that it can be seeded with an
arbitrary set of existing design points
• It has been shown that executing a series of these space filling DOE’s
with a projection of the new DOE center and levels can be an effective
optimization strategy
• Packaged as a new Optimization plugin
• The optimization plugin runs in a fully automatic mode a series of N
space filling DOE’s. The Nth DOE will be centered around a
projection of the improvement from the previous DOE. The DOE
search space will shrink and expand from iteration to iteration in order
to produce a more accurate optimum.

Adaptive DOE is a Space Filling Algorithm
Signal
Noise
Start +5 +10

Enhanced Error Handling
• Currently if any component fails, execution of the sim-flow branch
containing the failed component stops. Advanced users want the
sim-flow branch execution to continue even if a component fails; and
they would handle all the failures on their own
• Enhanced Error Handling fulfills this requirement – disabled by
default
• A check box in component Properties dialog
• When Enhanced Error Handling is enabled on a component
• the component exposes two output parameters COMP_ERR_CODE
(integer typed) and COMP_ERR_MSG (string typed)
• the component never fails, the execution is guaranteed to proceed to the
next component
• failures are captured and messages are populated in to
COMP_ERR_MSG output parameter
• COMP_ERR_CODE has default value of -231, updated to 0 on success,
and to 1 on failure
• subsequently, COMP_ERR_CODE may be used for conditional branching

Support
Certified Simulia Support and Training Partner
Dedicated Support Team
Email : support @viascorp.com
Phone : +1 (832) 301-0881
Regular Webinars, Online Training
Onsite Visit as Needed

Thank you
85

ABAQUS 2018 Technical Update

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