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  • SIMULIA / Abaqus / Engineous

    - ein Update

    Martin KssnerDassault Systemes Simulia GmbH

    [email protected]

    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 fluids 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 problems 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 strategy 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 stableit 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: Hashins 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 (cos2) ) ) ) psi under side only

    Note : strain discontinuities in doubler region

    Example (Payload Fairing)

    Composites supported in both /Standard and /Explicit solver/Standard (20 psi) /Explicit (20 psi)

  • Example (Payload Fairing)

    Composites supported in both /Standard and /Explicit solver/Standard (20 psi) /Explicit (20 psi)

    Example (Payload Fairing)

    Analysis in /Explicit carried out to collapse of structureApplied 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 deviatoric left Cauchy-Green tensor causes troubles when calibrating hyperelastic 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 KssnerDassault Systemes Simulia GmbH

    [email protected]