Improving Your Structural Mechanics Simulations with Release - Ansys · PDF fileImproving Your...

© 2011 ANSYS, Inc. October 24, 20111

Improving Your Structural Mechanics Simulations with Release 14.0

Todd McDevitt, PhD PEProduct Strategy & PlanningANSYS, Inc


Structural Mechanics Themes

MAPDL/Workbench Integration

Physics coupling

Rotating machines

Composites & Fracture Mechanics

Application Customization

Thin structures modeling

Contact analysis

Performance

Advanced Modeling

Geometry Handling

Listening to your needs, we have been able to identify a number of themes which form the basis of our roadmap and guide our developments


What will Release 14.0 bring you?


Let’s now take a closer look at some topics



Finite Element Information Access within ANSYS Mechanical


Spot Welds

Connections created internally at the solution level are available and can help understand the results

Reviewing Connections

Weak springs and MPC contacts as generated by the solver


Nodes can be grouped into named selectionsbased on selection logic, using locations or other characteristics – or manual selections

Selecting Nodes

Box Selection Node Picking Lasso Selection


Applying Loads and Orientations to Nodes

“Nodal Orientation” allows users to orient nodes in an arbitrary coordinate system.

Direct FE loads and boundary conditions can be applied to node selections.

Nodes are oriented in cylindrical system for loads and boundary condition definitions


Results on Node Selections

Results are displayed on elements for which all nodes are selected.

Nodes named selections allow to scope on specific regions of the mesh or remove undesired areas.

Results with first layer of quads removed

Results on quads layers only


Restart and Direct FE Loads

Nodal Forces and Pressures objects can be added to a restart analysis without causing the restart points to become invalid.

Other loads can now be modified without losing the restart points.

Analysis Settings tabular data: No restart point is lost

Added after initial solve

Second Load step modified for restart


Avoid Resolves with Post Commands

Adding post command snippets after a solution does not require resolving the entire solution.

This is the default setting if the user adds a post command object.



Linear Dynamics in ANSYS Mechanical


Workbench and Mechanical enhancements

→MSUP transient analysis supported

→Pre‐stress MSUP harmonic

→Joint features can now be used in harmonics, random vibration analysis

→Reaction force & moment results are now supported

Modal Superposition Transient

Joints in HarmonicAnalyses

Reaction Forces in Harmonic Analyses


Physics Coupling

Data Mapping


Motivation

Engineering organizations often use external files to transfer quantities from one simulation to another.

Efficient mapping of point cloud data is required to account for misalignment, non matching units or scaling issues.


Supported Data Types

New at R14.0


Increased Accuracy

The smoothness of the mapped data depends on the density of the point cloud.

Several weighting options are available to accommodate various data quality.

Triangulation versus Kriging


Validating the Mapped Data

Visual tools have been implemented to control how well the data has been mapped onto the target structure


Importing Multiple Files

Multiple files can be imported for transient analyses or to handle mappings to multiple bodies


Rotating Machines

Studying Rotordynamics in ANSYS Mechanical


Motivation

ANSYS Mechanical users need to be able to quickly create shaft geometriesas well as analyze dynamic characteristics of rotating systems

Industrial fan (Venti Oelde)


Geometry Creation

Geometries can be imported from a CAD system or imported from a simple text file definition for preliminary design


Import/Export of Bearing Characteristics

ANSYS provides an interface that allows to import bearing characteristics from an external file


Campbell Diagrams

Campbell diagrams are used to identify critical speeds of a rotating shaft for a given range of shaft velocities


Composites

Enhanced Analysis Workflow and Advanced Failure Models for Composites


Motivation

Efficient workflows and in‐depth analysis tools are required to model and understand complex composites structures


Manually Defining Layers on Simple Geometries

Users can define simple layered sections for a shell body as well as define thicknesses and angles as parameters


Defining Layers on Complex Geometries

For complex geometries, the ANSYS Composite PrepPosttool is used and layer definitions are imported in the assembly model in ANSYS Mechanical.

Courtesy of TU Chemnitz and GHOST Bikes GmbH


Advanced Failure Analysis

Crack growth simulation based on VCCT is available to simulate delamination.

Progressive damage is suitable for determining the ultimate strength of the composite (last‐ply failure analysis)

2D laminar composite

Initial crack

Start of damage (layer 1)

Progressed damage (layer 1)

Progressed damage (layer 3)


Customization

ANSYS Design Assessment


Motivation

Many of you have expressed the need for:→Computing and displaying specific results→Be able to achieve more complex “User defined results”


What is Design Assessment?

The Design Assessment system enables the selection and combination of upstream results and the ability to optionally further assess results with customizable scripts


Design Assessment for Advanced “User Defined Results”

Design Assessment enable users to extend user defined results capabilities with:

→Expressions using mathematical operators as supported by Python

→Coordinate systems, Units Systems

→Integration options

→Nodal, Element‐Nodal & Elemental result types

→Import from external tablesScript used to display scalar element data stored

in an external file


Thin Structures

Mesh Connections


Motivation

In order to connect meshes of different surface parts so as to share nodes at intersections, users do not always want or cannot merge the topologies at the geometry level. Mesh based connections are required.


Mesh Connections

Mesh connections work at part level:→As a post mesh operation→Base part mesh is stored to allow for quick changes in connections


Further Meshing Enhancements


Virtual Topologies Interactive Editing

Virtual topologies are handled more interactively through direct graphics interaction rather than tree objects.

User selects entities then applies VT operations

Direct access to operations from RMB menu


VT Hard Vertex, Edge and Face Splits

Hard vertices can be added at any location on an edge or a face.

Hard vertices can then be used to create face splits from virtual edges.


Contact Analysis

Rigid Body & Flexible Dynamics


Motivation

Many mechanisms and assemblies have components that operate through contact.


Performance Improvements

Valve: 158 sec elapsed time (2x speed up)

Piston: 9 sec elapsed time (7.5x speed up)

The applicability, robustness and efficiency of the contact has been improved for speed and accuracy –expect a typical 2‐5x speed‐up

Transition and “jump” prediction have been greatly improved


Projected Contact

Improved pressure results with surface projection

The Surface Projection Based Contact provides more accurate results (stresses, pressures, temperatures) and is now also available for bonded MPC contacts

Regular contact Projection based

Smoother temperature results on a multilayered structure


Contact accuracy and robustness

Contact stabilization technique dampens relative motions between the contact and target surfaces for open contactNew contact

stabilization prevents rigid motion

“Adjust to touch” causes rigid body motion and leaves a gap


Performance

Further benefits from GPU boards


Taking advantage of the latest hardware is mandatory to solve your large models.

A combination of relatively new technologies provides a breakthrough means to reduce the time to solution

Motivation

+


Distributed ANSYS Supports GPUs

2.1 MDOF, Nonlinear Structural Analysis using the Distributed Sparse Solver

GPU Acceleration can now be used with Distributed ANSYS to combine the speed of GPU technology and the power of distributed ANSYS


Speed‐up from GPU technology

Solder Joint Benchmark ‐ 4M DOF, Creep Strain Analysis

Results Courtesy of MicroConsult Engineering, GmbH

Linux cluster : Each node contains 8 Intel Xeon 5600‐series cores, 96 GB RAM, NVIDIA Tesla M2070, InfiniBand

MoldPCB

Solder balls


Advanced Modeling

Material Models & Methods


→Anisotropic Hyperelasticity plusViscoelasticity for strain rate effects

→Hyperelasticity coupled with Pore Pressure element

→Shape Memory Alloy enhanced with superelasticity, Memory effect, New Yield Function, Differentiated Moduli (Austenite, Martensite)

→Holzapfel Model ‐ Capture the behavior of fiber‐reinforced tissue

Advanced Materials for Biomechanical Applications

‘Hydrocephalus’ analysis Hyperelastic material with porous media

Stent modeling using shape memory alloys


Nonlinear materials support for coupled field elements

Coupled field‐elements for strongly coupled thermo‐mechanical analysis now accounts for plasticity induced heat generation along with friction effects

Friction Stir Welding including heat generation due to friction and plastic deformation


Moisture Diffusion

Moisture induces hygroscopic stresses and alters thermal stresses.

Coupled‐field elements allow to incorporate moisture effects in thermal, structural and coupled simulations.


Advanced Nonlinear Methods

User can now perform:→Buckling from a nonlinear prestressedstate with dead loads (new subspace eigensolver)

→3D rezoning for very large deformations for a wider range of materials and boundary conditions.

Hot‐Rolling Structural Steel Analysis with 3‐D Rezoning

Buckling of a pre‐stressed stiffened container


Coupled structures/acoustics simulations

Coupled problems are modeled more efficiently:→Quadratic tetrahedral acoustics elements→New acoustics sources→Absorbing areas→Enhanced PML formulation → Near and far‐field parameters


Advanced Modeling

Brake Squeal


• Complex Eigen solve• Animate: Complex Mode Shape• Contact Status at Pads

ANSYS Solution for Brake Squeal

CAD Mesh & Connection

Setup & solver

Post Processing

Bi‐Directional CAD Connectivity

• Automated Contact Detection

• Provides for sliding contact with friction• No match mesh needed• Supports higher order elements • Automated Meshing

• Flexibility to use Linear & Non‐linear solver capabilities

• Root locus plots• Correlation of modes• List Strain energy per component per modeFriction sensitivity study

• Physical prototyping time consuming and expensive

• Provide more analysis early in the design cycle

• Parametric Study by changing friction coefficient

• Run set of DOE’s• Reuse symmetric modes and just run un‐symmetric part

• Significant time reduction

• Can Include Squeal and Contact damping• ‐ Sliding velocity

dependent Friction


Physics Coupling

System Optimization with Rigid Body Dynamics and Simplorer co‐simulation


Motivation

Most mechanisms and assemblies are managed via control systems.

System simulation, including the details of the mechanism or assembly, are needed in order to improve modeling accuracy, fidelity and ultimately system optimization.


Linking Mechanical and Simplorer

Inputs and outputs are defined as “pins” in the Mechanical model and connected to the schematics of Simplorer


Some Examples

Aircraft Landing Gear

Simplorer schematic of hydraulic circuit and control

RBD model

Robotic Arm Control

Trace of arm trajectory


And there is much more…


…check the Release Notes!


Think also of the “Technology Demonstration Guide”


Questions?


Appendix


Customization

Application Customization Toolkit


Motivation

As a Mechanical User, you may want to:→ Customize menus→Create new loads and boundary conditions→Create new types of plots→Reuse APDL scripts without command snippets


What is the Application Customization Toolkit?

The Application CustomizationToolkit is a tool that facilitates customization of ANSYS Mechanical.

It provides a way to extend the features offered by ANSYS products.


Toolbar Customization through XML Files

<load internalName="Convection on Blade" caption="Convection on Blade" icon="Convection" issupport="false" isload="true">

<version>1</version>

<callbacks><onsolve>Convection_Blade_Computation</onsolve></callbacks>

<details><property internalName="Geometry" dataType="string" control="scoping"></property><property internalName="Thickness" caption="Thickness" dataType="string"

control="text"></property><property internalName="Film Coefficient" caption="Film Coefficient" dataType="string"

control="text"></property><property internalName="Ambient Temperature" caption="Ambient Temperature"

dataType="string" control="text"></property>

</details></load>

XML definition:


Python Driven Loads and Boundary Conditions

Python script:

# Get the scoped geometry:propGeo = result.GetDPropertyFromName("Geometry")refIds = propGeo.Value

# Get the related mesh and create the component:for refId in refIds:

meshRegion = mesh.MeshRegion(refId)elementIds = meshRegion.Elementseid = aap.mesh.element[elementIds[0]].Idf.write("*get,ntyp,ELEM,"+eid.ToString()+",ATTR,TYPE\n")f.write("esel,s,type,,ntyp \n cm,component,ELEM")

# Get properties from the details view:propThick = load.GetDPropertyFromName("Thickness")thickness = propThick.ValuepropCoef = load.GetDPropertyFromName("Film Coefficient")film_coefficient = propCoef.ValuepropTemp = load.GetDPropertyFromName("Ambient Temperature")temperature = propTemp.Value

# Insert the parameters for the APDL commands:f.write("thickness="+thickness.ToString()+"\n")f.write("film_coefficient="+film_coefficient.ToString()+"\n")f.write("temperature="+temperature.ToString()+"\n")

# Reuse the legacy APDL macros:f.write("/input,APDL_script_for_convection.inp\n")


Writing APDL Commands From the New Definition

! APDL_script_for_convection.inp

! Input parameters:esel,s,type,,10cm,component,ELEMthickness = 1.1film_coefficient = 120.temperature = 22.

! Treatment:/prep7et,100,152keyop,100,8,2.et,1001,131keyo,1001,3,2sectype,1001,shellsecdata,thickness,10secoff,midcmsel,s,componentemodif,all,type,1001emodif,all,secnum,1001type,100esurffinialls/soluesel,s,type,,100nslesf,all,conv,film_coefficient,temperaturealls

APDL

WB Mechanical


An Example: ACT driven Submodeling

Users simply select the coarse model’s results file, all APDL commands are automatically created – no more need for command blocks!


Advanced Modeling

Offshore Structures


Over the period of the design of an offshore structure –from Concept through FEED and Detailed Structural and Equipment Design – there are needs for many different analyses related to global structural design and integrity and detailed component level analysis. To ensure delivery timeliness, and reliability where costs of failure are so high, there is considerable value in compatibility between the respective tools. This is delivered by the ongoing integration of ANSYS AQWA in Workbench and delivery of enhanced capabilities in Mechanical/MAPDL for offshore structures analysis.

Importantly, ANSYS Structural Mechanics products now deliver the ability to conduct both global and detailed analysis of offshore structures subjected to various wave and environmental loadings.

Global Offshore Structures

Local joint flexibility analysis

Global hydrodynamics and structural analyses


• Hydrodynamic Time Response system enhancements include– Fenders (similar to contact)

• Allows connections between 2 structures or between a structure and a fixed point

– Articulations (similar to joints)

Further AQWA Integration in Workbench for Multi‐Body Wave Hydrodynamics

Offloading arm represented with series of typical articulations


Enhanced Environmental Conditions and Cable Behavior in AQWA

• Introduction of multi‐directional wave spectra allows more realistic modelling of real wave conditions, and is important for the accurate simulation of moored vessels and offshore platforms– Almost any combination of wave spectra to be modelled in the solver modules LIBRIUM, DRIFT and the Hydrodynamic Time Response system in Workbench

• To meet API standard (RP2SK), non‐linear axial stiffness can be used to define a mooring line

• Gaussian formulated wave spectrum now available in the core solver and the Hydrodynamic Time Response system


• Diffracted wave loading– Provides simplified pressure loading from Hydrodynamics Diffraction systems (AQWA) onto MAPDL system

• Harmonic Wave Loading– Regular wave loading now available for harmonic response analyses

– ANSYS FATJACK (for beam joint fatigue of framed structures) automatically reads the RST file data for harmonic load cases

• ANSYS BEAMCHECK (for member checks on framed structures) and ANSYS FATJACK now delivered with Mechanical installation– See Design Assessment for further information

Extended Wave Loading in Mechanical and links to Regulatory Code Checks

Vessel Loading Transfer from AQWA to MechanicalCourtesy of Vuyk Engineering Rotterdam


• Aeroelastic coupling (for wind turbine support structures) – Sequential

• Allowing structural (ANSYS) and aeroelastic (3rd party) analyses to be run independently

• Just use a provided MAPDL macro to write out input data for the aeroelastic analysis

– Fully coupled • Co‐simulation of structural and aeroelastic tools• Custom build of MAPDL required, with a macro to manage the data availability from and to MAPDL

Coupling Mechanical with 3rd Party Aeroelastic Tools for Offshore Wind Turbine Modeling

Images Courtesy of REpower Systems AG

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