Overview of Abaqus Lecture 1 L1.2 Overview • SIMULIA • What is Abaqus FEA? • Overview of Abaqus/CAE • Starting Abaqus/CAE • Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus Conventions • Documentation • Abaqus Environment Settings • Abaqus Fetch Utility • Abaqus/CAE Checklist • Working with the Model Tree • Workshop 1: Linear Static Analysis of a Cantilever Beam Introduction to Abaqus SIMULIA L1.4 SIMULIA • SIMULIA is the Dassault Systèmes brand that delivers a scalable portfolio of Realistic Simulation solutions including • The Abaqus product suite for Unified FEA • Multiphysics solutions for insight into challenging engineering problems • Lifecycle management solutions for managing simulation data, processes, and intellectual property • Headquartered in Providence, RI, USA • R&D centers in Providence and in Velizy, France • Global network of regional offices and distributors Introduction to Abaqus L1.5 SIMULIA SIMULIA Headquarters: Providence, Rhode Island Offices: USA: Overseas: California Indiana Michigan Ohio Rhode Island Texas Australia Austria China Finland France Germany (2) India Italy Japan (2) Korea Netherlands Sweden Argentina Brazil Czech Republic Malaysia New Zealand Poland Russia Singapore South Africa Spain Taiwan Turkey UK (2) Representatives: Overseas: Introduction to Abaqus What is Abaqus FEA? L1.7 What is Abaqus FEA? • Suite of finite element analysis modules Introduction to Abaqus L1.8 What is Abaqus FEA? • The structural analysis “solver” modules, Abaqus/Standard and Abaqus/Explicit, are complementary and integrated analysis tools.* • Abaqus/Standard is a general-purpose finite element module. It provides a large number of capabilities for analyzing many different types of problems, including many nonstructural applications. • Abaqus/Explicit is an explicit dynamics finite element module. • Abaqus/CAE incorporates the analysis modules into a Complete Abaqus Environment for modeling, managing, and monitoring Abaqus analyses and visualizing results. * Abaqus/CFD is a computational fluid dynamics analysis product; it is not discussed in this course. Introduction to Abaqus Overview of Abaqus/CAE L1.10 Overview of Abaqus/CAE • Integrates modeling, analysis, job management, and results evaluation seamlessly. • Provides the most complete interface with the Abaqus solver programs available. • Uses neutral database files that are machine independent. • Can be customized to create applicationspecific systems. Abaqus/CAE main user interface Introduction to Abaqus L1.11 Overview of Abaqus/CAE • Modern graphical user interface (GUI) of menus, icons, and dialog boxes • Menus provide access to all capabilities. • Icons accelerate access to frequently used features. • Dialog boxes allow you to input alphanumeric information and to select various options. Mechanical property submenu Elastic material form Visualization toolbox icons Introduction to Abaqus L1.12 Overview of Abaqus/CAE • Consistent environment • Functionality is presented in modules. • Each module contains a logical subset of the overall functionality. • Once you understand the presentation of one module, you can easily understand the presentation of the other modules. Introduction to Abaqus L1.13 Overview of Abaqus/CAE Part • Create the part geometry (and regions for sections, if necessary) • Define materials • Define additional part regions Assembly • Position parts for initial configuration. • Define and assign sections to parts or regions Step • Define analysis steps and output requests Mesh • Split assembly into meshable regions and mesh Property Interaction Load • Define contact and • Apply loads, other interactions BCs, and ICs to on regions or regions or named sets, and named sets; and assign them to assign them to steps in the steps in the analysis history analysis history Job • Submit, manage, and monitor analysis jobs Visualization • Examine results Introduction to Abaqus L1.14 Overview of Abaqus/CAE • Model Tree and the Results Tree • The Model Tree provides you with a graphical overview of your model and the objects that it contains. • The Results Tree is used to display analysis results from output databases as well as sessionspecific data such as X–Y plots. • Both trees provide shortcuts to much of the functionality of the main menu bar, the module toolboxes, and the various managers. • Some features of the Model and Results trees are discussed next. Introduction to Abaqus L1.15 Overview of Abaqus/CAE • Tree features • Navigation tool • Context sensitive RMB actions edit/create/suppress/query • Can effectively build most of your model from the tree • Model query/auditing • E.g., shows number of sections, materials, constraints currently defined • Shows status of certain features/items (invalid part, suppressed feature) • Comprehensive view of Abaqus model data • “Containers” expand to show objects and their hierarchy • Step dependent objects (e.g., BCs) appear in the STEP and LOAD containers Introduction to Abaqus L1.16 Overview of Abaqus/CAE • Tool tips • Float the mouse over a container or item… • “Pruning” the tree • You can set a certain container as the new “root” to reduce clutter • Keyboard shortcuts • Hide/show • Expand/collapse • Search • Delete items • Switch context • Filtering Introduction to Abaqus L1.17 Overview of Abaqus/CAE • Models are feature-based and parametric • A feature is a meaningful piece of the design. Models are constructed from numerous features; for example: • Geometric features fillet • Solid extrusion, wire, cut, fillet, etc. • Assembly features • Wheel must be concentric with the axle, the blank lies exactly in contact with the rigid die, etc. • Mesh features • Partition the mesh into different regions for different meshing techniques, seed different edges with different mesh densities, etc. Introduction to Abaqus solid extrusion cut Part with several annotated features L1.18 Overview of Abaqus/CAE • A parameter is a modifiable quantity that provides additional information for a feature; for example: • Solid extrusion parameters • Sketch of extrusion crosssection, depth of extrusion. • Cut • Sketch of cut cross-section, depth of cut. sketch of extrusion cross-section • Fillet parameter • Fillet radius. extrusion depth Solid extrusion parameters Introduction to Abaqus L1.19 Overview of Abaqus/CAE • Features often have parent-child relationships, such that the existence of the child depends on the existence of the parent; for example: • Delete the solid extrusion, and the hole and fillet cannot exist. solid extrusion cut fillet • Delete the part, and the mesh cannot exist. • Abaqus/CAE always asks to make sure that you want to delete the parent and its child features. Introduction to Abaqus • parent: solid extrusion • child: cut • child: fillet Example of Parent-Child Relationships among Features L1.20 Overview of Abaqus/CAE • Features can be modified by editing their parameters. • Aspects of the model can be regenerated. • Parametric studies are easy and natural. • Features can also be deleted or temporarily suppressed with the option to resume them later. • If a parent feature is deleted or suppressed, all its child features are also deleted or suppressed. Introduction to Abaqus L1.21 Overview of Abaqus/CAE • Interoperability • Abaqus/CAE is based on the concepts of parts and assemblies, which are common to many CAD systems. • Parts can be created within Abaqus/CAE. • Geometry can be imported from other packages and exported to other packages. • Existing Abaqus meshes can be imported for further processing. • Individual models can be copied between databases. Introduction to Abaqus L1.22 Overview of Abaqus/CAE • Dockable toolbars • Allow you to modify the layout and appearance of toolbars • Individual toolbars can be moved by dragging the toolbar grip • Toolbars can be “docked” at any of four docking regions located around the main window • Floating toolbars can be located anywhere • Orientation of floating toolbars can be controlled Dock Sites Introduction to Abaqus L1.23 Overview of Abaqus/CAE • Custom toolbars • Include shortcuts to functions not in standard toolbars or toolboxes • Can collect commonly used functions • To add a function to a custom toolbar: • Tools → Customize • Select the function in the Customize dialog box • Drag it onto the custom toolbar. • Assign an icon to represent the toolbar • Can be moved, docked, floated, or hidden in the same way as standard toolbars Introduction to Abaqus L1.24 Overview of Abaqus/CAE • Custom keyboard shortcuts • Available for most functions. • E.g., the key combination [Shift] + [Ctrl] + P may be assigned to Create Part dialog box • Default keyboard shortcuts for common functions (save, print, etc.) can also be reassigned. • Keyboard shortcuts must use one of the following keys or key combinations: • Any function key except F1 • [Alt] + [Shift] + key • [Ctrl] + key. You can also add [Alt] or [Shift] to modify any keyboard shortcut that includes the [Ctrl] key. Introduction to Abaqus L1.25 Overview of Abaqus/CAE • View manipulation • Toolbar to control view (pan, zoom, rotate, etc.). • Alternatively, can use a combination of keyboard and mouse actions: • Rotate: [Ctrl]+[Alt]+MB1. • Pan: [Ctrl]+[Alt]+MB2. • Zoom: [Ctrl]+[Alt]+MB3. • You can reconfigure these combinations to mimic the view manipulation interfaces used by other common CAD applications Introduction to Abaqus L1.26 Overview of Abaqus/CAE • 3D compass • View manipulation tool • Provides a quick and convenient way to change model view • Appears by default in each viewport; can be turned off if necessary • Uses three axes to indicate current model orientation • Can be clicked, dragged and oriented; by clicking different areas, specialized view manipulations can be performed: • Rotate freely about the model's center of rotation. • Rotate about a fixed axis. • Pan camera along a fixed axis. • Pan camera within a fixed plane. • Apply a predefined view. Introduction to Abaqus L1.27 Overview of Abaqus/CAE • What is a model database file (extension .cae)? • Contains all the information for any number of models. • Typically contains one model or several related models. • Only one model database can be opened in Abaqus/CAE at a time. Model database (.cae) Model 1 Model 2 Introduction to Abaqus Model 3 L1.28 Overview of Abaqus/CAE • What is a model? • Contains all the necessary information for an analysis. • Contains any number of parts and their associated properties. • Is independent of other models in the model database. • Objects such as parts and materials can be copied between different models in the same database. • Contains a single assembly of part instances, including the associated contact interactions, loads and boundary conditions, mesh, and analysis history. Model 1 parts material properties 1 assembly 1 analysis history Introduction to Abaqus L1.29 Overview of Abaqus/CAE • Models can be imported into one database from another • Model data from the imported database is copied into the current database. • E.g., parts, sections, assemblies, materials, loads, BCs, etc. • Analysis job definitions and custom data are not copied = + User A User B Introduction to Abaqus Master Model L1.30 Overview of Abaqus/CAE • What is Python? • Command language used by Abaqus/CAE. • Uses range from command scripting to creating customized applications. • Powerful and easy-to-use public domain, object-oriented programming language. • There are several books available on Python programming. • Additional learning materials are available online at www.python.org. • It is not necessary to learn Python programming to use Abaqus/CAE. Introduction to Abaqus L1.31 Overview of Abaqus/CAE • Commands issued during an Abaqus/CAE session are saved in journaling files containing Python scripts. Replay (.rpy) file All commands executed during a session, including any mistakes, are saved in this file. Journal (.jnl) file All commands necessary to recreate the most currently saved model database (.cae) are saved in this file. Recover (.rec) file All commands necessary to recreate the model database (.cae) since it was most recently saved are saved in this file. • Journaling files can be modified in any way appropriate for the Python language. Introduction to Abaqus Starting Abaqus/CAE L1.33 Starting Abaqus/CAE • Three options available: • Command line • abaqus cae = filename.cae • Opens Abaqus/CAE in current directory • Start menu (Windows) • Opens Abaqus/CAE in startup directory (set during installation) • Working directory can be changed (see next slide) • Double-click .cae or .odb file in Windows folder • Opens Abaqus/CAE in current directory Introduction to Abaqus L1.34 Starting Abaqus/CAE • Selecting a working directory • Can select a working directory • Default is startup directory • Subsequent file operations will use this directory for reading/writing • Job files will be written to the new working directory • This makes it easier to manage job files • E.g., keep all job files in a per-job directory Introduction to Abaqus Overview of Abaqus/Standard and Abaqus/Explicit L1.36 Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus/Standard • General-purpose finite element code. • Extensive and independent libraries: • Elements • Materials • Analysis procedures • Robust contact capability Introduction to Abaqus L1.37 Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus/Standard analysis types • Static stress/displacement analysis: • Rate-dependent or rateindependent response • Eigenvalue buckling load prediction Articulation of an automotive boot seal Introduction to Abaqus L1.38 Overview of Abaqus/Standard and Abaqus/Explicit • Linear dynamics: • Natural frequency extraction • Modal superposition • Harmonic loading • Response spectrum analysis • Random loading • Linear/Nonlinear dynamics: • Transient dynamics • Implicit or explicit integration Introduction to Abaqus Harmonic excitation of a tire L1.39 Overview of Abaqus/Standard and Abaqus/Explicit • Other analysis types available in Abaqus/Standard: • Heat transfer • Acoustics • Mass diffusion • Steady-state transport traction free rolling Steady-state rolling of a tire on a drum Introduction to Abaqus braking L1.40 Overview of Abaqus/Standard and Abaqus/Explicit • Multiphysics with Abaqus/Standard: • Thermal-mechanical analysis • Structural-acoustic analysis • Thermal-electrical (Joule heating) analysis • Linear piezoelectric analysis • Fully or partially saturated pore fluid flow-deformation • Fluid-structure interaction Thermal stresses in an exhaust manifold Introduction to Abaqus L1.41 Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus/Explicit • General-purpose finite element code for explicit dynamics • Designed for optimal computational performance with large models running many (10,000 to 100,000+) time increments • Extensive element and material libraries • Robust contact capability Introduction to Abaqus L1.42 Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus/Explicit (cont’d) • Simulates high speed dynamic events such as drop tests. • Explicit algorithm for updating the mechanical response. Drop test of a cell phone Introduction to Abaqus L1.43 Overview of Abaqus/Standard and Abaqus/Explicit • Abaqus/Explicit (cont’d) • Also a powerful tool for quasistatic metal forming simulations. • Annealing is available for multistep forming simulations Rolling of a symmetric I-section Introduction to Abaqus L1.44 Overview of Abaqus/Standard and Abaqus/Explicit • Multiphysics with Abaqus/Explicit • Thermal-mechanical analysis • Fully coupled: Explicit algorithms for both the mechanical and thermal responses adiabatic • Can include adiabatic heating effects • Structural-acoustic analysis • Fluid-structure interaction fully coupled temperature-displacement Two-stage forging, using ALE— contours of temperature Introduction to Abaqus L1.45 Overview of Abaqus/Standard and Abaqus/Explicit • Special features of Abaqus/Explicit: ALE • Adaptive meshing using ALE techniques allows the robust solution of highly nonlinear problems. • Mesh adaptivity is based on solution variables as well as minimum element distortion. Bulk metal forming • Elements concentrate in areas where they are needed. • Adaptation is based on boundary curvature. High speed impact Introduction to Abaqus L1.46 Overview of Abaqus/Standard and Abaqus/Explicit • Special features of Abaqus/Explicit: Coupled Eulerian-Lagrangian (CEL) • Define a domain in which material can flow for an Eulerian analysis • Flow problems • Structural problems with extreme deformation Eulerian mesh rod material Introduction to Abaqus L1.47 Overview of Abaqus/Standard and Abaqus/Explicit • Comparing Abaqus/Standard and Abaqus/Explicit Abaqus/Standard Abaqus/Explicit • A general-purpose finite element program. • A general-purpose finite element program for explicit dynamics. • Nonlinear problems require iterations. • Can solve for true static equilibrium in structural simulations. • Solution procedure does not require iteration. • Solves highly discontinuous highspeed dynamic problems efficiently. • Coupled-field analyses include: • Provides a large number of capabilities for analyzing many different types of problems. • Nonstructural applications. • Thermal-mechanical • Structural-acoustic • FSI • Coupled or uncoupled response. Introduction to Abaqus Abaqus Conventions L1.49 Abaqus Conventions • Units • Abaqus uses no inherent set of units. • It is the user’s responsibility to use consistent units. • Example: • N, kg, m, s or • N, 103 kg, mm, s etc. Common systems of consistent units Introduction to Abaqus L1.50 Abaqus Conventions • Example: Properties of mild steel at room temperature Quantity U.S. units SI units Conductivity 28.9 Btu/ft hr ºF 50 W/m ºC 2.4 Btu/in hr ºF Density 15.13 slug/ft3 (lbf s2/ft4) 7800 kg/m3 0.730 × 10−3 lbf s2/in4 0.282 lbm/in3 Elastic modulus 30 × 106 psi 207 × 109 Pa Specific heat 0.11 Btu/lbm ºF 460 J/kg ºC Yield stress 30 × 103 psi 207 × 106 Pa Introduction to Abaqus L1.51 Abaqus Conventions • Time measures • Abaqus keeps track of both total time in an analysis and step time for each analysis step. • Time is physically meaningful for some analysis procedures, such as transient dynamics. • Time is not physically meaningful for some procedures. In rateindependent, static procedures “time” is just a convenient, monotonically increasing measure for incrementing loads. Introduction to Abaqus L1.52 Abaqus Conventions • Coordinate systems • For boundary conditions and point loads, the default coordinate system is the rectangular Cartesian system. local rectangular coordinate system with YSYMM boundary conditions • Alternative local rectangular, cylindrical, and spherical systems can be defined. • These local directions do not rotate with the material in largedisplacement analyses. Boundary conditions on a skew edge Introduction to Abaqus L1.53 Abaqus Conventions • For material directions (i.e., directions associated with an element’s material or integration points) the default coordinate system depends on the element type: • Solid elements use global rectangular Cartesian system. Default material directions for solid elements • Shell and membrane elements use a projection of the global Cartesian system onto the surface. Default material directions for shell and membrane elements Introduction to Abaqus L1.54 Abaqus Conventions • Alternative rectangular, cylindrical, and spherical coordinate systems may be defined. 1 2 • Affects input: anisotropic material directions. • Affects output: stress/strain output directions. • Local material directions rotate with the material in large-displacement analyses. Introduction to Abaqus L1.55 Abaqus Conventions • Degrees of freedom • Primary solution variables at the nodes. • Available nodal degrees of freedom depend on the element type. • Each degree of freedom is labeled with a number: 1=x-displacement, 2=y-displacement, 11=temperature, etc. Introduction to Abaqus Documentation L1.57 Documentation • Primary reference materials • All documentation is available in HTML and PDF format • Abaqus Analysis User’s Manual • Abaqus/CAE User’s Manual • Abaqus Example Problems Manual • Abaqus Benchmarks Manual • Abaqus Verification Manual • Abaqus Keywords Reference Manual • Abaqus User Subroutines Reference Manual • Abaqus Theory Manual • The documentation is available through the Help menu on the main menu bar of Abaqus/CAE. Introduction to Abaqus L1.58 Documentation • Additional reference materials • Abaqus Installation and Licensing Guide (print version available) • Installation instructions • Abaqus Release Notes • Explains changes since previous release • Advanced lecture notes on various topics (print only) • Tutorials • Getting Started with Abaqus: Interactive Edition • Getting Started with Abaqus: Keywords Edition • Programming • Scripting and GUI Toolkit manuals • SIMULIA home page www.simulia.com Introduction to Abaqus L1.59 Documentation • HTML documentation • The documentation for Abaqus is organized into a collection, with manuals grouped by function. • Viewed through a web browser. • Can search entire collection or individual manuals Introduction to Abaqus L1.60 Documentation • Searching the documentation • Enter one or more search terms in the search field Terms in the search field: Appear in any order May or may not be adjacent Appear within the proximity criterion (default is a single section) The table of contents entry is highlighted The text frame displays the corresponding section Introduction to Abaqus L1.61 Documentation • Searching the documentation (cont’d) • Use quotes to search for exact strings Introduction to Abaqus L1.62 Documentation • Advanced search • Advanced search allows you to control the proximity criterion Introduction to Abaqus L1.63 Documentation • Advanced search (cont’d) Introduction to Abaqus Abaqus Environment Settings L1.65 Abaqus Environment Settings • The Abaqus environment settings allow you to control various aspects of an Abaqus job’s execution. • For example, setting a directory to be used for scratch files, changing the default memory settings, etc. • Environment settings hierarchy • Abaqus environment settings are processed in the following order: • The host-level environment settings in the site directory in the abaqus account directory. These settings are applied to all Abaqus jobs run on the designated computer. • The user-level environment settings in the home directory. These settings are applied to all Abaqus jobs run in your account. • The job-level environment settings in the current working directory. These settings are applied to only the designated Abaqus job. • The host-level environment settings are included in the release. • You can create an environment file abaqus_v6.env in your home directory and/or current directory. Introduction to Abaqus L1.66 Abaqus Environment Settings • Note: The value of the SCRATCH parameter is platform specific. • On UNIX platforms the default value is the value of the $TMPDIR environment variable or /tmp if this variable is not defined. For example, scratch="/tmp" • On Windows platforms the default value is the value of the %TEMP% environment variable or \TEMP if this variable is not defined. For example, scratch="c:\\temp" • For information on environment file settings refer to: “Using the Abaqus environment settings,” Section 3.3.1 of the Abaqus Analysis User's Manual. Introduction to Abaqus Abaqus Fetch Utility L1.68 Abaqus Fetch Utility • The Abaqus fetch utility allows you to extract sample Abaqus files that are provided with each release. • Files that may be extracted include input files, journal files, model databases, etc. corresponding to the Abaqus Example, Benchmark, and Verification problems. • The utility may also be used to extract scripts that create complete models corresponding to each workshop of this course. • The “answer” script name is noted at the end of each workshop. • To use the fetch utility enter the following command at the operating system prompt: abaqus fetch job=filename where abaqus is the command used to run Abaqus on your system. • For example, Abaqus release 6.10-1 it might be aliased to abq6101. Introduction to Abaqus Abaqus/CAE Checklist L1.70 Abaqus/CAE Checklist Must Have Parts At least one Must Have Materials At least one Must Have Sections At least one Must Have Section Assignments Made at the part level (container) Must Have Assembly (Instances) At least one part Must Have Steps (after Initial) Initial created for you Usually Need BCs (Boundary Conditions) Can be in Initial Step Usually Need Loads In Steps after the Initial Must Have Mesh Can be done on part or assembly Must Have Jobs To actually run the analysis Introduction to Abaqus Working with the Model Tree L1.72 Working with the Model Tree • The Model Tree is a convenient tool for navigating and managing your models and analysis results. • The Model Tree provides a visual description of the hierarchy of items in a model. • The arrangement of the containers and items in the Model Tree reflects the order in which you are likely to create your model. • A similar logic governs the order of modules in the module menu—you create parts before you create the assembly, and you create steps before you create loads. Introduction to Abaqus L1.73 Working with the Model Tree • Example: The following figure shows a suggested order to create the cantilever beam model . (Note: This order is not unique.) Introduction to Abaqus L1.74 Working with the Model Tree • Alternatively, follow the order of modules in the module menu to create the model. Part • Create the part geometry • Define materials • Define and assign sections to parts or regions Step • Define analysis steps and output requests Mesh • Mesh the part Property Assembly • Position the part for initial configuration. Interaction • Not applicable for this example Load • Apply loads and BCs to regions or named sets; and assign them to steps in the analysis history Job • Submit, manage, and monitor analysis jobs Introduction to Abaqus Visualization • Examine results Workshop 1: Linear Static Analysis of a Cantilever Beam L1.76 Workshop 1: Linear Static Analysis of a Cantilever Beam • Workshop tasks • Follow detailed instructions to create a simple cantilever beam model using the Abaqus/CAE modules. • Submit a job for analysis. • View the analysis results. Introduction to Abaqus