[PDF] - Hybrid MachineTool y Simulation Contents 1. General PDF Document

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Hybrid MachineTool y Simulation

이병흠 과장 ㈜ 캐즈테크

iMBD

Machine Tool Components:

 Computerized Numerical Contr

l

 Programmable Logic Controlle

r

 Electrical Components  Mechanical Components

[SIDL]

FEM

iMBD

MBS

 Process Technology

MFBD

SLIDE 8

8

Applying flexibility to Multi Body Systems

Vision: Enhanced representation of machine behavior at the system level by consideration of component elasticity

General Introduction to Machine Tool Simulation

consideration of component elasticity  Increase the simulation accuracy by recording component deformations, mechanical resonances, … Integrated stress analysis based on dynamic loads Consideration of static and dynamic component deformations. Example: rocker arm

Abb. Positionsfehler
Abb. GeschwindigkeitsfehlerAbb. Beschleunigungsfehler

Collection of machine resonances and natural oscillations due to periodic stimulation

Applying flexibility to Multi Body Systems

General Introduction to Machine Tool Simulation

f = 40 Hz n

140 160 180 N 200 0,8 0,9 1 1,2

Zeit Cutting Force

1,1

stimulation

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Mechatronical Simulation

Apart from structural effects the transient

General Introduction to Machine Tool Simulation

behavior of machine tool is highly affected by the numerical control systems. Fore example: the Kv - Factor (speed/stroke gai n) Indicates the speed in which a particular positio n error is set to zero. The higher the Kv the fast er the system but this also makes the system u stable…

[BÜRGEL]

Mechatronical Simulation

… the simulation of the control system shows these effects easily. But only in

General Introduction to Machine Tool Simulation

… the simulation of the control system shows these effects easily. But only in combination with the structural/mechanical model the developer is able to see how this is affecting the machine tool behavior

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Hybrid machine tool modeling

The efficiency of machine tools is highly affected by several aspects. Common simulations (MBS – FEM – Control) have to be combined to validate the transient

General Introduction to Machine Tool Simulation

( ) behavior of machine tools correctly. Due to the cost in time, money and accuracy this combination requires greater focus

n the system level each machine tool component has to be simulated in.

discretization

Workshop@:

ptimization

General Introduction to Machine Tool Simulation Value generating by Machine Tool simulation - Examples

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❶ Circularity Tests (ISO 230 T2)

 Standard acceptance certificate for general machine tools

General Introduction to Machine Tool Simulation

 The NC-Control pretends an ideal circular orbit for the die

holder

 Circular movement by controller or spline  Variations of the pretended and measured circle are relate

d to typical machinery failure

[WECK]

❶ Circularity tests (ISO 230 T2) (2)

 RecurDyn validation

General Introduction to Machine Tool Simulation

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❷ Frequency response / impact analysis

 Through a targeted impact the structure will be stimulated to

s

cillate in a broadband spectrum

General Introduction to Machine Tool Simulation

cillate in a broadband spectrum

 Goal is to rebuild the characteristic function for the transfer behavior  RecurDyn validation

❸ Chatter vibration

 Effected by the interaction of dynamic machine- and the dynamic cutting-behavior  St bilit

l l t d b N i t C it i

General Introduction to Machine Tool Simulation

 Stability calculated by Nyquist Criteria

With

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❸ Chatter vibration (2)

General Introduction to Machine Tool Simulation

[WLZ]

Challenges Solution

Machine tool simulation challenges

General Introduction to Machine Tool Simulation

 CAE Technology :

System level simulations of MT require multi-discipline analysis capabilities

 RD/IMD Technology

provides integrated MBD, FEA and Controls functionality in one single environment

 Machine Tool Know – How :

Compared to MT manufacturers, software companies typically don’t have  the same level of application know-how  measurement equipments for model validation

 MT companies adapted software implementation :

The above mentioned special situation of

 Technology Consortium :

between:  Technical University of Munich: Technology provider  FRAMAG (Austria): MT manufacturer  FunctionBay GmbH: Software implementation

 MT specific toolbox:

Predefined component library, analysis and post-processing capabilities The above mentioned special situation of MT companies require customization of standard software packages and post processing capabilities

Technology – Partners:

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General Multi Body Simulation (StartUp)

MFBD Modeling MFBD Modeling of Machine Tool Parts

Goal: Get a short Introduction to the several body types in RecurDyn When should I use which body formulation in machine tool When should I use which body formulation in machine tool simulation Get sensitive for body limitations

Rigid Bodies

Body of infinite extent Inertia are determined by

MFBD Modeling

2nd order DE sin   q g q   q u   Reduce Order Equations 1st order explicit DE                q g u u q sin    y 1st order implicit DE

sin ) , , (           q g u u q t y y F   

1st order BDF

Body of infinite extent. Inertia are determined by geometry or user ❶ Geometry construction via:

Primitive objects and Boolean operations Import from common CAD systems

(E.g.: STEP, PARASOLID, IGES, …) ❷ Degrees of freedom : #6DoF

1 order BDF

h y y t y

n n

    

1

y 

Explicit solver

n n n n n n

q gh u u h u q q sin

1 1

   

 

Implicit solver

sin

1 1 1 1

     

    n n n n n n

q gh u u h u q q

Newton Raphson iteration Iterative solution

❸ Connections to any desired coordinate ❹ Contacts on the topology geometry

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RFlex Bodies

FE-Modell of the body is condensed to the stiffness betwe

MFBD Modeling

FE-Modell of the body is condensed to the stiffness betwe en so-called interface nodes by the use of the Craig-Bamp ton method ❶ Meshing via Preprocessor (E.g.: RD-Mesher; NX 7.5 ) ❷ Modal Condensation via FEM-Solver (E.g.: RD-Mesher; Nastran) ❸ Degrease of Freedom: #6DoF a Interface-Node ❹ Contact formulation not available

FFlex Bodies

Non-linear FE-model of the body serves all degrees of freedom on every

MFBD Modeling

Non linear FE model of the body serves all degrees of freedom on every node ❶ Meshing via Preprocessor (E.g.: RD-Mesher; NX 7.5 ) ❷ Degrees of Freedom: #6DoF each Node ❸ contacts trough so-called patch sets available on every node ❹ Calculation via: “Relative Nodal Displacement Method“ (BAE, CHOI, CHO)

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Lesson1: MFBD Modeling

 Build up a simple fixed bar with a applied load

MFBD Modeling

 Build up a simple fixed bar with a applied load  import a FFlex model  Import a RFlex model  Analyzing the difference

Exploring RecurDyn

RFlex Bodies are linear

 Modal Reduction is linear and only valid for small deformat ions

MFBD Modeling

 No large rotations of the flexible body concerning the defor mations (But the flexible body can lead large rotations in th e MBS)

Abb. Modale Reduktion
Abb. Nicht – lineare Lösun

g mit RecurDyn/FFL EX

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General Multi Body Simulation (StartUp)

General Components I

Goal: Get a short Introduction of Constraints Forces and Expressions When should I use which abstraction Get sensitive for solving times

Bearing and Clutch Simulation:

The simulation of rotational degrees of

General Components I

freedom could be set on different system level abstraction. Starts by fixing single DOFs to the flexible simulation of each bearing ball. The level of discretization had to be set

n the values to be generated by the

simulation

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Bearing and Clutch Simulation:

Due to the fact that bearing and

General Components I

clutches are only components of machine tools the focus of the simulation has to be set on a low level discretization but with the maximum effects to see in the simulation

Lesson2: Modeling of General Components I

 Editing a driving system with different

General Components I

 Editing a driving system with different kinds of bearing models  Post processing the effects  Building up clutch models  Post processing the effects

Exploring RecurDyn

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General Multi Body Simulation (StartUp)

Cutting Force Implementation

Goal: Showing two different ways of cutting force implementation in RecurDyn Building up an MBS model of a cutting force

 This theory is based on the division of the cutting force along the cutting edge b

y using the Thales circle This leads trough the shear stress along the cutting e

Cutting force Theory - Merchant

Cutting Force Implementation

y using the Thales circle. This leads trough the shear stress along the cutting e dge and in this way trough the active force.

[MÜLLER]  Based on the geometrical set of the cutting force is calculated:

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 For cutting processes with geometrically determined bits the reacting force cou

ld be set as three different orthogonal force vectors

Cutting force Theory – Viktor&Kienzle

Cutting Force Implementation

ld be set as three different orthogonal force vectors

 Viktor-Kienzle formulates a correlation of the chip geometry and the specific

cutting force g

[FISCHER]  As shown on real cutting processes the specific cutting force is just constrained

by the chip height – the with is not effecting the specific cutting force in a releva

Cutting force Theorie – Viktor&Kienzle

Cutting Force Implementation

by the chip height the with is not effecting the specific cutting force in a releva nt way

[FISCHER]  with this information the principal value of the cutting force is calculated (chip g

eometry A= 1mm x 1mm) and available on tables. Thou the reacting forces can be calculated as:

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Cutting force Practicaly – Viktor&Kienzle

 To calculate the Victor-Kienzle cutti

ng force in a multi body system it is

Cutting Force Implementation

ng force in a multi body system it is necessary to assign the correct val ue of the chip area

 However you need to setup the mo

del with three reference Markers

 To get the natural deflection of the c

lamping a dummy body is necessar p g y y

y. This dummy body gets the feed o

f the tool and the avoiding position

f the work part

 The force formulation is set as thre

e Expressions

Lesson3: Cutting force implementation (Victor-Kienzle)

 Building up a 3 component force with

Cutting Force Implementation

 Building up a 3 component force with cutting force characteristics in a lathe model

Exploring RecurDyn

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Cutting force Evaluation

Evaluation Examples:

Cutting Force Implementation

 Design of cutting profile  Creating stability charts  Evaluation of cutting process  Evaluation of cutting limits

RecurDyn & FBG.MachineTool Specific Simulation

Driving Systems

Goal: Showing the main machine tool driving systems Showing abstraction levels that could be simulated Introduction to the FBG.MachineTool

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Ball Screw

 Stiffness model

Driving Systems

Iey

x y z   

Ic

Nut Spheres

Iex

x y z   

Ix Iy

Shaft Ball Screw (2)

 Automatic load / torque “hand-over” from

ne beam element to the next

Driving Systems

ne beam element to the next

 Implementation as user-written subroutine  RecurDyn force element: matrix force

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Lesson4: Driving a MachineTool via Ball Screw Systems

 Implementing flexible driving system

Driving Systems

Possible System level abstraction  Joint coupler (RecurDyn Professional Functionality) Not recommended – caused on value generation  Timoshenko Beam (RecurDyn FBG MachineTool) R  Implementing flexible driving system

Exploring RecurDyn

 Timoshenko Beam (RecurDyn FBG.MachineTool) R ecommended

Linear guides

 Automatic parabolic load distribution to nodes with

automatic stiffness correction

Driving Systems

automatic stiffness correction

 RD/MT automatically creates matrix forces elements

according to user specified parameters (guide stiffness , geometric dimensions, …)

bodypos m bodypos m ∆x/2 ∆x n-2 n-1 n+1 yI xI yn xn xB n nodepos An-2 An-1 An An+1 An+2 n+2 ∆x/2 ∆x n-2 n-1 n+1 yI xI yn xn xB n nodepos An-2 An-1 An An+1 An+2 n+2

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Linear guides (2)

 Examples and validation

Driving Systems

Lesson5: Driving a Machine Tool via Linear Guides

 Getting started with driving large displacements on flexible bodies

Driving Systems

Possible System level abstraction  Joint (RecurDyn Professional Functionality) Not recommended – caused on value generati

n

 Contact Modeling (RecurDyn Professional Fu nctionality) sim ulation of non-stiff guiding systems (E.g.: air b earing) g g g p

Exploring RecurDyn

earing)  Timoshenko Beam (RecurDyn FBG.MachineT

ol) Driving large displacements on flexible

systems, were the bending along the dri ving axis is dominant  FFlex (RecurDyn FBG.MachineTool) Get all detailed information from every node of the FFlex model

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RecurDyn & FBG. MachineTool Specific Simulation

Response Analysis

Goal: Showing a typical analyzing method in the Machine Tool simulation Signal Handling Advantage of measurement comparison

Response Analysis

 Investigate the structural behavior of the machine tool by different vibrati

n excitation (Impact Hammer, Shaker etc.)

Response Analysis

n excitation (Impact Hammer, Shaker etc.)

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Lesson6: Response Analyses with Impact Hammer

 Generate Impact Force

Response Analysis

 Generate Impact Force  Generate Impact Signal  Evaluate Signal  Evaluate Structural Machine Tool Behavior

Exploring RecurDyn RecurDyn & FBG.MachineTool Specific Simulation

Actuation Simulation

Goal: Modeling an alternating circular motion for a circularity test Run a circularity analysis with the FBG.MachineTool

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Lesson7: Driving a Circularity Test via Expression

 Generate driving motion

Actuation Simulation

 Generate driving motion  Generate a FBG.MachineTool circularity test  Evaluate simulation

Exploring RecurDyn RecurDyn & FBG.MachineTool Specific Simulation

Actuation Simulation

Goal: Getting Started With RecurDyn Colink Generate controller Communication Design simple controllermodel

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Mechatronic Simulation

 Controller and Structural Machine  Use integrated controller design for optimization of control design and pa

Actuation Simulation

 Use integrated controller design for optimization of control design and pa

rameters depending on structural behavior of machine tool

 Include model of Electrical driving Engines to generate real feed torque

Lesson8: Driving a Circularity Test via CoLink

 Generate interface (Plant In and Outputs)

Actuation Simulation

 Generate interface (Plant In and Outputs)  Generate simple PID- Control  Generate controlled circularity motion  Evaluate simulation

Exploring RecurDyn

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RecurDyn & FBG.MachineTool Specific Simulation

Hybrid MachineT

ol Simulation

Goal: Building up a complete machine tool model in a row (practice the last chapters) Driving first analysis

Lesson9: Combine Knowledge

Hybrid MachineT

ol Simulation

 Build up a circularity test model in a row  The goal is to characterize the structura

l behavior of the ground and the middle structure

Exploring RecurDyn

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RecurDyn & FBG.MachineTool Specific Simulation

PostProcessing

Goal: Post Process The Hybrid Model of the last chapter

Lesson10: PostProcessing

PostProcessing

 Build up a circularity test model in a row  The goal is to characterize the structura

l behavior of the ground and the middle structure

Exploring RecurDyn

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Future Developments of FBG MachineTool

Mechatronic Simulation optimization

 Providing standard control system library in RecurDyn CoLink as an “eas

y to change” library for the fast integration of different control systems int

Future MachineT

ol Developments

y to change library for the fast integration of different control systems int

the multi body system

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Real-Time Programmable Logic Controller (PLC) coupling

 Programmable Logic Controller (SERCOS III)  P

iti t ll (S i L b)

Future MachineT

ol Developments

 Position controller (ScicosLab)  Simulation (FunctionBay RecurDyn)