SIMULIA / Abaqus / Engineous

- ein Update

Martin KüssnerDassault Systemes Simulia GmbH

Martin.KUESSNER@3ds.com

Content

• Integration of processes

• Multiphysics

• Unified FEA

• Parallelization

• Material laws

• Simulation Lifecycle Management

• Optimization/Robust Design

• Conclusion

Integration of processes

„FEA is not all that is out there ….“

Innovation Integration ProcessCentered on Virtual Experience

Automotive

Aerospace

Shipbuilding

Industrial Equipment

High Tech

Consumer Goods

Consumer Packaged Goods

Life Sciences

Energy

Construction

Business Services

Multiphysics

„There is more that matters than just

stresses and strains“

StructuralStructural

Multiphysics in Abaqus Unified FEA

• Abaqus enables coupling of multiple fields

Thermal

Pore pressure

Electrical

Piezo-electrical

Acoustics

Fluid flow

Structural

Courtesy: Honeywell FM&T

Courtesy of Dr. Michelle Hoo Fatt (University of Akron)

Coupled Eulerian-Lagrangian (CEL)

• Enhances the ability of Abaqus/Explicit to model fl uids and materials that undergo extreme deformation

Capability consists of:A three-dimensional Eulerian

element typeSupport for all materials in

Abaqus/Explicit except hyperelasticity and anisotropy

General contact between Eulerian and Lagrangian domains

Parallel processingTarget applications include:

Hydroplaning, water impact, earth penetration, sloshing, bird strike

Fully supported in Abaqus/CAE

Volume fraction tool being used to fill a bottle for a drop test

Coupled Eulerian-Lagrangian (CEL)

• Uses a multi-material finite element formulation

• Volume-of-fluids method tracks material boundaries within an Eulerian domain

• Conforming meshes are not required

Provides a specialized technique to simulate FSI pr oblems that include:

Complex structural contact conditions including self-contact Large structural deformations and displacementsVery high-speed dynamicsDamage, failure, or erosion at the fluid-structure interface

Coupled Eulerian-Lagrangian (CEL)

• Example: Hydroplaning

• When a vehicle is driving in the rain, water trapped between the road and tire leads to pressure build-up and possible loss of traction

• Tire manufacturers use simulation to design tread patterns that reduce the possibility of hydroplaning

• CEL easily handles the complex contact conditions (“pinching”) that occur during hydroplaning simulation

Unified FEA

„Re-Using instead of Re-Doing“

11

Implicit/explicit integration

• Unified FEA™ is a key component of our product strat egy

• Implies the ability to easily transfer models and results between implicit and explicit solution technologies

• Implicit/explicit integration

• Most elements and materials that are common to both solution technologies can be transferred

Nonlinear Dynamics

• Abaqus/Standard (=Implicit)

• Uses a second-order accurate, implicit scheme called the Hilber-Hughes-Taylor (HHT) rule.

• This is a generalization of the Newmark method.

• Second-order accurate means the scheme integrates a constant acceleration exactly.

• The method is unconditionally stable: any size time increment can be used, and the solution will remain bounded.

• Abaqus/Explicit (=Explicit)

• Uses a second-order accurate, explicit integration scheme.

• The method is conditionally stable—it gives a bounded solution only when the time increment is less than a critical value.

Comparing implicit and explicit

integration scheme

Implicit

• Time increment size is not limited: generally fewer time increments required to complete a given simulation.

• Each time increment is expensive since each requires the solution for a set of simultaneous equations.

Explicit

• Time increment size is limited: generally many more time increments are required to complete a given simulation.

• Each time increment is relatively inexpensive because not required to solve a set of simultaneous equations.

– Most of the computational expense is associated with element calculations (forming and assembling I).

The model is in equilibrium at the beginning and end of the increment

Seek to control the residual at an intermediate point

Residual at half-increment (half-step residual)

Implicit

• Ideal for problems where the response period of interest is long compared to the vibration frequency of the model.

• Difficult to use explicit dynamics effectively because of the limit on the time increment size.

• Use for problems that are mildly nonlinear and where the nonlinearities are smooth (e.g., plasticity).

• With a smooth nonlinear response Abaqus/Standard will need very few iterations to find a converged solution.

Explicit

• Ideal for high-speed dynamic simulations

– Require very small time increments; implicit dynamics inefficient.

• Usually more reliable for problems involving discontinuous nonlinearities.

– Contact behavior is discontinuous and involves impacts, both of which cause problems for implicit time integration.

– Other sources of discontinuous behavior include buckling and material failure.

Abaqus/Standard

• Comprehensive linear & nonlinear implicit general purpose finite element analysis of structural, thermal, acoustic & mechanism simulations

• Integration with Abaqus/Explicit provides maximum flexibility for multi-physics simulation (“Unified FEA”)

• Sophisticated contact, failure, material modeling & other advanced nonlinear capabilities

• High-performance direct and iterative solvers with support for shared and distributed memory configurations

• Powerful interfaces for user customization

Abaqus/Explicit

• Comprehensive explicit finite element analysis of structural, thermal, acoustic & mechanism simulations

• Integration with Abaqus/Standard provides maximum flexibility for multi-physics simulation (“Unified FEA”)

• High-performance solver with support for shared and distributed memory configurations

• Powerful interfaces for user customization

Courtesy BMW

“Abaqus Unified FEA”

• Abaqus import capability can transfer a model or part of a model, together with associated state information, between an Abaqus/Explicit analysis and an Abaqus/Standard analysis

Abaqus/Explicit

Abaqus/Standard

Abaqus/Explicit

Abaqus/Standard

Abaqus/Explicit

Abaqus/Standard

Overlapping material library

• Damage and failure of fiber-reinforced composites

• Example: Hashin’s damage initiation criterion of unidirectional composites is available in Abaqus/Standard and Abaqus/Explicit

• The model captures four different damage mechanisms

• Fiber rupture

• Fiber buckling and kinking

• Matrix cracking

• Matrix crushing

• Damage evolution consistent with damage framework introduced in Version 6.5

• Abaqus/Explicit ↔ Abaqus/Explicit and Abaqus/Standard↔ Abaqus/Explicit import

Example (Payload Fairing)

• Pressure load = 20 x (cos 2θ) θ) θ) θ) psi under side only

Note : strain discontinuities in doubler region

Example (Payload Fairing)

• Composites supported in both /Standard and /Explici t solver

/Standard (20 psi) /Explicit (20 psi)

Example (Payload Fairing)

• Composites supported in both /Standard and /Explici t solver

/Standard (20 psi) /Explicit (20 psi)

Example (Payload Fairing)

• Analysis in /Explicit carried out to collapse of st ructureApplied Load = 50 psi over 1.0 second

P = 42.5 psi (t = 0.85)

Nose Tip Displacement

Parallelization

„We need to become MUCH faster ….“

Parallelization and performance

• DMP direct sparse solver

• Scalability significantly improved

• Memory use noticeably reduced when running on 4 or more compute nodes

• Unsymmetric solver now supported (important for contact simulations)

• Multiple linear loads cases and Riks method now supported

• DMP is an effective strategy for Abaqus/Standard

Courtesy of the DANA Corporation

Major Breakthrough in Abaqus Performance

• Expanded procedure support

• Improved scalability

• Reduced memory requirements

92%Speed Up

Courtesy DANA 9.2M DOF

Material Laws

„Things became really difficult ….“

Material law

„The calibration of the second invariant of the deviatori c left Cauchy-Green tensor causes troubles when calibrating hyperelast ic material law.“

What to do with these kind of information?

Simulation Lifecycle Management

„What to do with all the data and how to

store the processes….?

Simulation Lifecycle Management

• SLM means:

• Bringing Order to Simulation:

• Management of Data, Methods and Processes

• Connecting users to each other and the enterprise

• Leveraging Simulation IP:

• Capturing simulation know-how and related decisions

• Extracting and re-using the built-in value of simulation activity

• An Open Platform to Manage and Deploy Applications:

• Workflow chaining and job submission

• Connector architecture for 3rd party applications

SLM Sneak Preview

1

2

3

4

5

1. 3DSearch2. 3DCompass3. 3DNavigation4. 3DHeads-Up5. Contextual

Buddy List

Optimization / Robust Design

Isight for Abaqus: Benefits

• Reduce design time

• Execute multiple simulation studies automatically overnight

• Parallel submission of optimization, Monte Carlo, and DOE jobs on multiprocessor machines or in conjunction with LSF

• Improve quality

• Design-to-target for simulation attributes

• Account for variation in materials, loads, tolerances, and operating conditions

• Find the best design

• Understand which model parameters drive targets

• Trade off design alternatives in real time with colleagues and other stakeholders

The Big Picture – Automated Design Strategies

Y1

ConstraintBoundary

Y2

Initial Best Design

Feasible Infeasible (safe) (failed)

X2

X1

Outputs

Inputs

“Shop” for the best design

DOE:

Critical Factors

and Initial Design

Isight for Abaqus: Design of Experiments (DOE)

Perform trade-offs and understand the design space

• Capabilities• Determine which input variables have the

most influence on your simulation outputs

• Use to build approximation models

• Estimate of an Optimal Design

• Types• Parameter Studies

• Orthogonal Arrays

• Full Factorial Arrays

• Optimal Latin Hyper Cube

• Latin Hyper Cube

• Central Composite

• Import Outside Experiments

Isight for Abaqus: Approximations

Build from DOE samples, speed up calculations from Six Sigma, speed up live performance tradeoffs

• Types• Response Surface Model (to 4th order)

• Radial Basis Function (RBF)

• Capabilities• Automatic setup

• Automatic error estimation

• Effects graphs

• Interactive tradeoffs

• Simulation Surrogate

The Big Picture – Automated Design Strategies

Y1

ConstraintBoundary

Y2

Initial Designfrom DOE

Feasible Infeasible (safe) (failed)

Outputs

Improve Design Performance

Optimization(Approximations)

Optimized Design

Isight for Abaqus: Optimization

Drive toward a target performance

• Capabilities• Formulate variables, constraints, and multiple

objectives

• Multi-objective Pareto fronts

• Types

• Gradient: NLPQL

• Multi-Objective: NCGA, AMGA

• Pattern: Hooke-Jeeves and Downhill Simplex

• Exploratory: Multi-Island Genetic Algorithm(MIGA), Adaptive Simulated Annealing (ASA)

• Automatic Optimization: Pointer

Automatically configures NLPQL, an evolutionary algorithm, Downhill Simplex, and a linear solver

Sim approximation surrogate

The Big Picture – Automated Design Strategies

Y1

ConstraintBoundary

Y2

Feasible Infeasible (safe) (failed)

Outputs

Improve Design Quality

Design for Six Sigma

Robustness and Reliability Analysis and Optimization

Robust and ReliableDesign

% Unreliable% Reliable

Conclusion

SIMULIA / Abaqus / Engineous

- ein Update

Martin KüssnerDassault Systemes Simulia GmbH

Martin.KUESSNER@3ds.com