Ansys Workbench Dynamics v11

8/19/2019 Ansys Workbench Dynamics v11

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© 2006 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

ANSYS WorkbenchDynamicsv11.0

ANSYS WorkbenchDynamicsv11.0

Tim Pawlak

ANSYS, Inc.

Tim Pawlak

ANSYS, Inc.


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IntroductionIntroduction

• Dynamics background

– ANSYS long established

flexible dynamic capabilities

– Major v11 development theme

• Objectives

– Improved existing capabilities

– Established new capabilities

– Achieve mechanism simulation

– Combine advantages of rigidand flex representations

– Offer exceptional product


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ModelModel

• Geometry import as usual

– Associative

– Parametric

• Stiffness types

– Flexible• Usual 3D meshed models

• Nonlinear materials allowed – Rigid

• Limited to single body parts

– Flexible Beam (beta)

• Avoids over constraint• Solution time shorter

• Limited to single body parts

– Mixtures of rigid and flexible parts


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Joints and Coordinate SystemsJoints and Coordinate Systems

• Joints

– New way to connect parts

– Associative to geometry

– Between two parts or part to ground

• By faces

• By edges and vertices (beta)

–

Have up to two coordinate systems• Reference

• Mobile (optional)

• Coordinate systems

– Inherent to joint definition

– Associative to geometry

– Geometry based construction

– Options for precise positioning



Joint TypesJoint Types

• Fixed

• Revolute

• Translational• Slot

• Cylindrical

• Universal

• Spherical

• Planar

• General

• 6 Degrees of Freedom

• Combinations of fixed and free



ConfigureConfigure

• Model assembly

• Interactive real time operation

–

To validate mechanism definition• Graphical joint DOF triad

– Mouse pick selection to locate and orient

• Set position

– Useable for all analysis types



Analysis TypesAnalysis Types

• New way of categorizing analyses

– Not input and output driven

–

Objective driven• Clearly delimitates capabilities

• Links analyses and transfers data

• Joints applicable to

– Static Structural

– Flexible Dynamic

– Rigid Dynamic

– Modal

– Harmonic (beta)



Flexible Dynamic Analysis TypeFlexible Dynamic Analysis Type

• Finite element formulation of geometry and

equations for motion

• 9 joints types

• Longitudinal spring/damper

• Torsional spring/damper (beta)• HHT implicit transient time solver

• Time history displacements, velocities,

accelerations, forces, stresses, etc.



Rigid Dynamic Analysis TypeRigid Dynamic Analysis Type

• Relative degree of freedom formulation of

geometry and equation of motion

• 9 joints types

• Longitudinal spring/damper

• Torsional spring/damper (beta)• Runge Kutta explicit time solver

• Time history displacements, velocities,

accelerations, forces, etc.



General Load InformationGeneral Load Information

• Types

– Constant, table, function

• GUI controls for defining loads – Details view

– Timeline

– Tabular data



General Load InformationGeneral Load Information

• Types

– Displacement/Rotation

– Velocity

– Acceleration

– Force/Moment

• GUI operations in timeline ortabular data

– Activate/Deactivate

– Multi select



Rigid Dynamic LoadsRigid Dynamic Loads

• Methods

– Primarily by joint conditions

– Optionally to parts by using joint to ground

• With appropriate DOFs free (even all DOFs free)

• Requirements

– Mechanism must be ground in some manner

–

Free floating parts can be represented by a general joint toground with all DOFs free

• Table loads

– Data points are fit within load step, but not between load steps

– Curve display is piecewise linear (i.e. fit is not shown)

– Warning issued if fit is inappropriate

• Inappropriate is area under fitted curve differs significantly fromarea under piecewise linear curve


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ResultsResults

• Data

– Saved in files managed

by the WB project

system (.rst and .mbd)• Probes

– Deformation, position,

rotation (beta), velocity,

angular velocity,acceleration, angular

acceleration, energy,

force, moment

• Force and moment – Graphic indication by

arrow


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ResultsResults

• Charts

– Useful for comparisons of tabular data (loads and results)

– Normalizes data when of dissimilar type

– Applicable to objects within the same model branch

• And across model branches (beta)

• Timeline “Zoom to Range”

– Useful for detailed investigation of tabular data

– Horizontal and vertical zoom (vertical beta)


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Strategy RecommendationsStrategy Recommendations

• Utilize options that parts canbe rigid/flexible

• Remember that there are

more options now forconnecting parts

• Build up the mechanism partby part

• Operate the mechanism

interactively to validate itsbehavior before launchingsolution

• Consider the flex beamoption because it is typicallyquicker and avoids over-constraint

• Leverage strengths of rigidand flex solvers


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CMS Flexible RepresentationCMS Flexible Representation

• CMS stands forComponent ModeSynthesis

• Linear approach torepresent part flexiblyusing 3D mesh at

reduced computationalcost

• Similar to superelement approach

• Available in the ANSYSsolver


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CMS within WorkbenchCMS within Workbench

• Analysis Types

– Dynamic

– Static

• Made possible by

Command objects

• Named Selection used togroup mesh

– Variable to activate

convenient grouping• Results available for post

processing Vane Example


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CMS Vane Deform vs. Regular CMS Vane Deform vs. Regular


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CMS Vane Stress vs. Regular CMS Vane Stress vs. Regular


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CMS Joint Force vs. Regular CMS Joint Force vs. Regular


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Computation Time ComparisonComputation Time Comparison

CMS

Release 11.0BETA

UP20061004

INTEL NT

Maximum Scratch Memory

Used = 45.966 MB

CP Time (sec) = 27.281

Elapsed Time (sec) = 56.000

Date = 10/05/2006

Regular

Release 11.0BETA

UP20061004

INTEL NT

Maximum Scratch Memory

Used = 43.744 MB

CP Time (sec) = 124.312

Elapsed Time (sec) = 137.000

Date = 10/05/2006


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CMS Landing Gear ExampleCMS Landing Gear Example


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CMS Landing Gear Close-UpCMS Landing Gear Close-Up


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CMS SummaryCMS Summary

• Available in WB

via Commands

• Enablessignificant

computational

efficiency

• Limited to linear

materials


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Miscellaneous Features IMiscellaneous Features I

• Automatic joint generation

– Based on geometry (similar to auto contact generation)

– Finds candidate revolute and fixed joints

• User preferences

– Automatic joint and/or contact generation “on” or “off”

• Graphics window RMB (right mouse button)

–

Go To (bodies, joints, etc.) – Disable Transparency

– Hide All Other

– Flip Reference/Mobile

– Body Views• Standard, reference, and mobile windows

• Isolates the parts involved in a joint

Mi ll F t II


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Miscellaneous Features IIMiscellaneous Features II

• Over constraint “Joint Checker” (partially beta)

– Estimate of mechanism available degrees of freedom

– Estimate of individual joint DOF condition

( )P d t P k i (T t ti )


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Product Packaging (Tentative)Product Packaging (Tentative)

• ANSYS Dynamics Productivity Pack*

– WorkBench enabled task add-on for

• ANSYS Structural• ANSYS Mechanical

• ANSYS Multiphysics

– Not available as standalone

– Enables

• Joint construction

• Configure feature

• Rigid Dynamic analysis type

– Advantages

• Flexible and rigid dynamics capabilities in a single system

* Name subject to change

F tF t


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FutureFuture

• Joints

– Stops and locks

– Friction

– Stiffness

– Events

– Hydrodynamic bearings

– Gears

– Cable and pulleys

• Contact

– For rigid bodies

• Diagnostics

– Callout where and why mechanism numerically fails

• Leverage combination

– Share constraint info from rigid solver to flex

Ansys Workbench Dynamics v11

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