1. MSC.Software – December 2003
ADAMS/Rail Training
MSC.Software – December 2003

2. ADAMS/Rail Highlights
Setting configurations
Standard Interface
Defining Subsystems
Creating Assemblies
Accessing the Curve Manager
Performing an analysis
Results postprocessing
Template Builder
Build Menu
Hardpoints / Construction Frames
Definition of communicators

3. Database Management
Every project is associated with a database (“cdb”) containing different tables (“tbl”) corresponding to the different model files
Default writable database can be set by the user
No limit to the number of databases
Defaults can be changed and saved in configuration file
(Tools / Save ADAMS/Rail Configuration)

4. Configuration Files
Settings are defined in the file .acar.cfg stored in the home directory
Tables are defined in the acar.cfg file in the ADAMS/Rail installation directory
ENVIRONMENT MDI_ACAR_PLUS_AVIEW yes

5. Now it’s your turn... (1)
Refer to the “Getting Started Using ADAMS/Rail” guide - Introductory section
Identify the configuration file .acar.cfg for your specific user
Change your user mode to “expert”
Start ADAMS/Rail and get familiar with the graphical interface
Create your own database (“training”)
Specify the <training> database as default writable with priorital search order
Save configuration in .acar.cfg file

6. Expanded Integration Platform
High-Speed
Vehicle
Dynamics
CAD
Controls
ADAMS/Rail
Durability
In-House Solutions
Given what mentioned in the previous slide, the integration platform provided by ADAMS/Rail branches also out to the Vampire solver technology, which enables efficient standard vehicle dynamics simulations.
NVH
FEM

7. Case Study: Alstom Business: Railway vehicles manufacturer
Challenge: Optimize new streetcar for rollover stability and derailment avoidance
Solution: Evaluated the vehicle behavior virtually to optimize the design
Value: Improved safety; greater confidence
Example of successful usage of our solutions at major railway OEM:
Business: ALSTOM has annual sales in excess of 22 billion Euro and employs 120,000 people in over 70 countries. Leading solutions-provider to the rail industry world-wide, ALSTOM (with Siemens is second only to Bombardier in the railway vehicle manufacturing market) offers a complete range of products and services from integrated transport systems, rolling stock of all types, through signaling and train-control systems, to complete customer service packages.
Challenge: During the design phase of the new streetcar for the city of Turin Italy, characterized by fully low floor vehicle and articulated bogies with independent wheels, Alstom Ferroviaria decided to use virtual prototyping to investigte the dynamic behavior of the complete system in order to optimize the aspects related to the curve approaching, derailment and rollover. One of the main goals of this vehicle investigation, has been to obtain a precise identification of the dynamic profile of the vehicle, required by the customer to optimize the balance between performance and safety.
Solution: Alstom used ADAMS/Rail to analyze the dynamic behavior of the vehicle, taking into account several wheel profiles, optimizing the wheel-rail contact and consequently saving maintenance costs and guarantee an high level of safety. Virtual derailment and rollover investigation has been a key issue for the virtual investigation, due to the low-floor layout of the vehicle and to the high center of gravity. Preliminary studies showed that also the wheel-rail profiles should be taken into account. In fact, several simulations have shown that this effect can be reduced by using wheel profiles characterized by having no sharp flange profiles.
Value: Alstom can now obtain a vehicle layout with no critical conditions for derailment. The investigation of the curving behavior has been important to evaluate the bogie steering versus the wheel consumption. Not less important is the ability of reaching an optimized vehicle configuration, due to the network characteristics (altitude, irregularities, track curvature, etc.) and the tuning of linkages, weights and stiffness/damping devices for life cycle cost evaluation. The presence of flexible components influences the results of the derailment safety – the results with flexible frames are less conservative, since the bogie can better “adapt” to the track curve.
Reference:“Analysis of an independent wheels tram vehicle” – M. Lenti, Alstom Ferroviaria, at 16th European MDI Users Conference, 15-Nov-01
Analysis of an independent wheels tram vehicle – part II” – M. Lenti, Alstom Ferroviaria, at 1st MSC.Adams European Users Conference, 14-Nov-02
Movie: Streetcar model negotiating a narrow curve. The model contains flexible components in the bogie frame. The simulation allows to identify that in right hand curves the rear bolster flexibility is dominant for the curve negotiation, whereas in left hand curves the front bolster flexibility is dominant.
“The simulation produced results in agreement with all service conditions and the overall dynamic behavior. Derailment and rollover stability measurements have been matched with a maximum error of 3%.”
-- Massimo Lenti Manager R&D, Alstom IPS

8. FVPD with ADAMS/Rail Systems Subsystems Components
Here is one of the strengths of FVPD (functional virtual product development) -- system-level simulation. It’s not enough to optimize at the component level – if you do, the subsystem may not perform optimally when you put all the components together. The same idea applies to optimizing at the subsystem level – it’s not good enough.
A real strength of ADAMS/Rail is the ability it provides to optimize complete product-level performance. For suppliers, this can increase their confidence that their subsystems will meet the performance specifications of their OEM customer. For OEMs, this can increase their confidence that when they assemble all the sub-systems into a system, it will be optimized, at least in so much as it meets their initial system-level performance targets.
For both OEMs and suppliers, ADAMS/Rail enables them to communicate their designs and demonstrate their performance much earlier and more often throughout the NPD cycle. This more effective dialogue gives both parties the flexibility to adjust their designs or performance criteria if necessary before committing to expensive hardware construction.
Components 9

9. ADAMS/Rail Environment Structure
EXPERT
USER
Templates
Subsystems
Assemblies
STANDARD USER
VEHICLE
MODEL
Topology
Files
Accessories
Running gear
Car body
Vehicle Data Files
Dampers
Suspensions
Airsprings
Bumpstops
Wheels
Vehicle
Model
Automatic generation of the railway system
Track Data File
Irregularities
along track
Track
centerline
layout
Rail profiles
System & Analysis
Configuration
Contact
model
Analysis type:
stability
curving
switch

10. Standard Interface Accessible by users with every privilege
Subsystems are created referencing existing templates
Minor Role of subsystems must be defined
Front, Rear, Middle, Any
Same template can be referenced several times
COPY no longer necessary!
Possibility of defining model data
Masses - Inertias
Suspensions - Dampers - Wheel properties

11. Subsystem Adjust Menu is automatically adjusted for every subsystem
Model data can be assigned and modified
Subsystems can be shifted
Subsystem order can be defined

12. Templates & Subsystems
One single Template…
...Several Subsystems with different model configurations

13. Working with Property Files
Property Files are ASCII formatted files containing the data of every modeling element
Can be modified with
Text editor
Curve Manager
Are read into the complete assembly prior to the analysis
Wheel profiles are described in wheel property files

14. Assembly Procedure Template: _ERRI_Bogie Template: _ERRI_Bogie
Major_Role: Running_Gear
Subsystem: ERRI_Rear_Bogie
Minor_Role: Rear
Template: _ERRI_Bogie
Major_Role: Running_Gear
Subsystem: ERRI_Front_Bogie
Minor_Role: Front
Template: _ERRI_Car_Body
Major_Role: Car_Body
Subsystem: ERRI_Car_Body
Minor_Role: Any

15. Wagon Order
Introduced in order to allow the use of multiple instances of the same template for more than one wagon
Requested for General Assembly (more than one “Car Body” template) x

16. Now it’s your turn... (2)
Go through the “Getting Started Using ADAMS/Rail” guide - Standard Interface section (page 6 to 17)
Create subsystems referencing existing templates
View / modify model data
Create an assembly using your subsystems

17. Performing an Analysis (1)
Several type of analysis can be performed:
Preload analysis (calculation of suspensions preload) : Can be performed only in interactive mode, and it doesn’t need any additional file.
Linear analysis (evaluation of vehicle modes, excluding the effect of wheel/rail contact) : Can be performed in interactive, batch, or files only (external) mode, and it doesn’t need any additional file.
Stability analysis (evaluation of vehicle modes, including effect of wheel/rail contact, evaluation of critical speed, stability map) : Can be performed in interactive, batch, or files only (external) mode, and it needs an additional file:
contact configuration file (*.ccf)

18. Performing an Analysis (2)
Several type of analysis can be performed:
Dynamic analysis (fully non-linear vehicle analysis for curving, switch crossing, comfort analysis) : Can be performed in interactive, batch, or files only (external) mode, and it needs several additional files, according to the type of analysis performed:
Contact configuration file (*.ccf)
Track property file (*.trk)
Flexible track property file (*.frp) [optional]
Guiding rail property file (*.grp) [optional]

19. Performing an Analysis (3)
The following files are generated when submitting an analysis:
ADM (ADAMS/Solver Deck)
ACF (ADAMS/Solver Commands)
NAM (Request Configuration)
LOG (Analysis information)
VEL (for stability analysis, range of velocities used)
The following files are generated when the analysis is executed:
REQ (Request file, with user defined output)
GRA (Graphics file, with data for animation)
OUT (Ouptut file, with additional results)
MSG (Message file, the analysis execution log)
RES (Results file, all state outputs, optional)
The following command is used to run the analysis externally:
adams03 arail ru-solver file.acf

20. Preload Analysis
Calculates the preload for the suspensions of the vehicle:
Suspension elements
Shear Springs
Airsprings (Nishimura, Krettek, Krettek Coupled
Bushings
Preloads automatically applied
Allows to choose only a subset of the vehicle suspension

21. Preload Analysis – Cont.
Should be run before other analysis
Apply a preload at suspension system
Will update subsystem file automatically
No need to run again using a saved model
Will result in transient effect if no preload is applied first

22. Linear Analysis
Linear analysis allows to investigate the behaviour of the vehicle suspension looking at the modal behaviour (damped or undamped
Example 1 (Bounce mode)
Example 2 (Roll mode)
Example 3 (Pitch mode)

23. Stability Analysis (1) Open Loop
Multiple analysis at different vehicle velocity
No check is done on the stability of the vehicle

24. Critical Speed?
Real part become positive (should be negative in order to delay over time…)

25. Critical Speed?
Critical damping smaller than 0

26. Stability Analysis (2) Closed loop
The critical speed of the vehicle is identified for different value of conicity.
Stability map is automatically generated if more than one conicity value is specified
A frequency range can be specified to avoid instability due to undesired modes
Specification of critical damping to determine stability (0%, 5%,...)

27. Stability Analysis (2)
This feature allows the automatic generation of a stability map for a railway vehicle, for a user specified conicity range. The map shows clearly the domains where the vehicle will run stable and those where it will run unstable and is a precious tool for railway vehicle design.

28. Dynamic Analysis (1)
Allows to run a wide range of simulation, according to the parameters and property files specified.
Track configuration file
Contact configuration file
Track flexibility property file (only when using flexible track)
Guiding rail property file (only when using track with guiding rail)

29. Dynamic Analysis (2) Wheel Flat Description Cruise Control
This feature is available only when using wheel property files of format WPF_2. It allows to model wheels with variable radius and variable profiles.
Cruise Control
This feature allows to specify a constant speed or a velocity profile ( *.vpf file) to be followed during the simulation using a PD controller. The Cruise Control Setup Panel is available in the Simulate menu in the main toolbar.
More...

30. Running simulation with switch: Example Results...
Dynamic Analysis (3)
Switch crossing simulations
Available only when using track files in format TRK_4.
Detailed description of track profile variation.
Possibility to introduce effect of guiding rail (with flexible connection to the ground).
Possibility to define rail and guiding rail at different sections (see TRK_4).
Profiles used for the switch description are stored in the database table “wheel_rail_profiles.tbl”, and are in TeimOrbit (property file) format. (Example *.rpr file).
Running simulation with switch: Example Results...

31. Specifying W/R Contact
Wheel/rail contact elements implemented with exclusive rights from ArgeCare:
Quasi-linear Element – Basic Features
Described through conicity parameter etc.
Suitable for stability analysis in modal space
Tabular Element - Basic Features
Pre-computed contact geometry
Two-dimensional contact
Suitable for standard dynamic analysis (comfort, curving on wide curves)
General Element - Basic Features
On-line computation of contact geometry
Three-dimensional contact
Flexible, non-elliptical multi-point contact
Suitable for severe contact condition analysis (switch crossing, narrow curving, wear…)
ArgeCare is a German organization very well known in the railway world. They developed the most sophisticated wheel/rail interconnection routines available on the market. Those routines are based on the theory of Kalker which is the most widely accepted contact mechanics model.
It is possible to specify different wheel/rail contact types, independently for each wheel-rail interconnection. The contact configuration is handled through the use of Teim Orbit property files. Three main contact elements are provided:
-          TAB
-          GEN
-          QLT
plus the LIN contact element which represents the contact with a linear spring-damper support for every wheel-rail interconnection, used mainly for model debugging.
The TAB element uses a force formulation and allows the roll movement of wheelsets and its dependency in respect to the lateral and vertical wheelset displacements. This contact element is fully non linear, and uses a pre-computed contact geometry table. It allows comfort, dynamic stability and curving simulations where the contact mechanics can be handled as 2D.
The GEN element derived from the well known element 21 of the Medyna solver (from the ArgeCare company) and is probably the most sophisticated contact description algorithm existing in the market at the moment. It allows fully 3D multi point contact description. It takes for example into account the influence of wheelset yawing on contact mechanics, and multiple contact points on each wheel, both on tread, flange and flangeback can be taken into account. This contact element provides accurate results for every configuration where the rail-wheel contact mechanics gets to the extreme, like very narrow curving (streetcar simulation).
The QLT element is based on the TAB element and uses automatically generated circular profiles, corresponding to the quasi linear contact parameters (effective conicity and so on) given in the contact configuration file as input. This contact element can be used for linear stability analysis (calculation of hunting modes a.s.o.)

32. Contact Mechanics
Wheel/rail interconnection represented with Hertzian theory applied to elastic surfaces with variable curvature

33. Contact Mechanics
Independently represented with a GFORCE on left/right wheel/rail pairs
Contact geometry is precomputed and stored in tables (TAB) or calculated on-line (GEN)
Table is calculated for different values of wheel lateral displ.

34. Contact Mechanics
The QLT element is based on equivalent conical profiles (linear approximation of wheel/rail contact)
Suitable for stability analysis in frequency domain
Equivalent conical profiles are calculated corresponding to the “conicity” value inputed by the user

35. Contact mechanics Contact parameters can be visualized in plots
Real wheel/rail profiles used for the model graphics

36. Friction variability
Possible to specify in the CCF file the variability of the friction coefficient as spline in function of:
Track distance
Creepage
With lateral coordinate on rail / wheel
Friction Coefficient
Creepage
Distance

37. Examples: Wheel/Rail Contact
Lift-Off Simulation
Wheel Profile variability
Here are two examples to show the power of the contact elements embedded in ADAMS/Rail.
Example of lift off: thanks to the flexible contact (not based on constraints) it is immediate to model real lift off, indispensable for realistic derailment/rollover simulatins. This is evident in this animation which shows a wheelset pushed left and right by a sinusoidal force: the wheels lift off the rails and bounce back on them when the gravity field prevails.
Example of wheel profile variability: railway wheels, during the forging process, are manufactured in such a way that they are never perfectly circular. This out-of-roundness originates dynamic effects on the contact forces and can interact with the permanent way (which is itself a flexible system, due to the connections between rails and sleepers). The movie shows the dynamic effect on the vertical wheel/rail contact forces due to the fact that the wheel is not perfectly circular.

38. Postprocessing
Stability and comfort toolkit accessible through separate menus
Time-dependent requests accessible through Curve Toolbar
Request names defined through NAM file
CFG file allows to customize request names

39. Using Comfort Toolkit
PostProcessing->Comfort Toolkit

40. How to create Request
Only in Template Builder

41. Section Length?
In UIC Comfort Toolkit, Section Length表示的是每隔多遠的距離輸出一次結果點. 以下圖為例, 速度為30m/sec, 分析時間10秒, section length為6m, 所以輸出的時候一共有50個section.(30*10/6=50)

42. How to check total load?
Tool->Aggregate Mass

43. How to check contact table?
Tool->RSGEO Interface

44. Plot Configuration File
Allow to store in an ASCII file the plot formatting executed once according to own standards
PLT file can be modified with text editor
PLT file can be used for different analysis referred to the same model

45. Now it’s your turn... (3)
Complete the “Getting Started Using ADAMS/Rail” guide - Standard Interface section (pages 18 to 24)
Perform a preload analysis to check the nominal force values of the suspension elements
Perform a stability analysis to investigate the stability of the system
Perform a dynamic analysis over a straight track with lateral ramp to investigate dynamic stability
Perform a dynamic analysis over a curve track to investigate curving behavior

46. Template Builder Accessible by users with expert privileges
Major Role of template must be defined
Running Gear
Car Body
Accessory
Possibility of defining model topology
Parts
Attachments
Forces
Possibility of defining model structure
Communication between different templates

47. The Build Menu Build Menu organized in sequential order
Standard modeling elements
General parts
Attachments
Kinematic (joints)
Compliant (bushings)
Railway modeling elements
Railway vehicle parts
Railway vehicle interconnections

48. Symmetrical Approach
Every modeling element can be created as “left”, “right” or “single”
Symmetrical elements can be automatically connected to symmetrical parts
Left-Right symmetry can be broken in Standard Interface

49. Hardpoints and Construction Frames
Define location in global reference frame
Can be created/modified in TB
Can be modified in SI
Are used to define parameterization of the models
Construction frames
Define location and orientation with respect to a local reference frame
Belong to the GROUND part
Cannot be modified in SI

50. Accessing Hardpoints Table

51. Mount Parts
Used to generate connection elements between parts belonging to different templates
Symmetry is implied from coordinate reference
Mount parts are assigned to the parts they replace during the assembly, if not assigned to GROUND
Connectivity can be tested with an automatic procedure

52. Switch Parts Used to define adjustable topology in templates
Are defined in Template Builder but can be accessed in Standard Interface
“Parts list” contains the different part the Switch Part can represent
Switch to Part is defines as default in TB

53. Template Generation Checklist
Create new template (Major Role: Running_Gear)
Define hardpoints (will be parametric)
Define construction frames
Create parts (i.e. wheelsets, bogie frames…)
Create connection elements (i.e. joints…)
Define Mount Parts (when necessary)
Define Communicator Outputs (when necessary)
Define elastic connections (i.e. suspensions, dampers...)
Model data defined in TB can be default values as they can all be accessed in SI

54. Troubleshooting
“Graphical topology”, accessible through Database Navigator
“Highlight Connectivity”, accessible through Tools menu

55. Now it’s your turn... (4)
Go through the “Getting Started Using ADAMS/Rail” guide - Template Builder section (page 25 to 60)
Create a Running Gear template
Investigate the correctness of the model
Perform linear analysis on a General Assembly containing the bogie model only to check the plausibility of the system

56. Communicators
Provide transfer of data in two directions between different subsystems
Two types of communicators:
Input Communicators
Request information from other subsystems (name prefix: ci[lrs]_)
Output Communicators
Provide information to other subsystems (name prefix: co[lrs]_)
Data are correctly exchanged when I and O have same “matching names”
Different classes available to provide exchange of different type of information

57. Communicator type: Mount
Enable to connect parts belonging to different templates
Exchange a part name (“Car Body”) between the different subsystems
An input communicator is automatically created with a mount part using the name of the mount part:
mts_car_body ==>
cis_car_body
Communicator
Output
Mount Part

58. Output communicators
To create an output communicator the following must be specified:
Matching Name
Entity and Type
To Minor Role (inherit = defined by subsystem minor role)
Parameter to be exchanged (i.e. for mount CO: part name)
For “double Attachment Type” templates:
Attached to model with
Same
Next
Wagon Order

59. Matching Communicators
Communicators will exchange information during assembly when:
Having matching names
Being of opposite types (one I, one O)
Being of same symmetry type
Being of same class
Having same minor role or be assigned a role of “any”
Belonging to subsystems with same wagon order
Correct definition of communicators can be tested with the help of an automatic procedure

60. Communicator Test

61. Now it’s your turn... (5)
Complete the “Getting Started Using ADAMS/Rail” guide - Template Builder section (page )
Create a Car Body template
Define communication of this template with the Running Gear template
Test validity of communicators
Create a new wagon assembly using the user templates
Reproduce one simulation performed on the example assembly to check the validity of the user model

62. Assembly Example 1

63. Assembly Example 2

64. Assembly Example 3

65. Now it’s your turn... (6) Starting from the ERRI_Car_Body assembly:
Create a template called “buffer” with:
major role = “accessory”
attachment type = “double wagon attachment”
Create in the template two hardpoints (“front” and “rear”) with distance one from the other = 1m, height from ground = 1.3 m
Create two mount parts:
mts_cb_front, over “hps_front”, attached to model with same wagon order
mts_cb_rear, over “hps_rear”, attached to model with next wagon order
Create a longitudinal spring between the two mount parts (use as property file a modified version of <shared>\springs.tbl\manch_trail_rod.spr to take into account the new free length)

66. Now it’s your turn... (7)
Modify the ERRI_Car_Body template introducing two additional output communicators:
“cb_to_buffer_front”, matching name “cb_front”, attached to model with same wagon order
“cb_to_buffer_rear”, matching name “cb_rear”, attached to model with same wagon order
Create a subsystem referred to the buffer template, minor role = any, wagon order = 1, shifting it of 24 m forwards
Shift the subsystems of the original ERRI_Car_Body assembly of 25 m forwards
Create new subsystems for the second wagon using the same templates, but with wagon order = 2 (refer to the Getting Started Guide), calling them ERRI_Front_Bogie_2 etc.

67. Now it’s your turn... (8)
Create a new General Assembly including the following subsystems:
ERRI_Car_Body
ERRI_Front_Bogie
ERRI_Rear_Bogie
ERRI_Car_Body_2
ERRI_Front_Bogie_2
ERRI_Rear_Bogie_2
Buffer
Execute a linear analysis to investigate the influence of a coupling element between the car bodies

68. Customization
Customization features available from the Build Menu in TB/SI
Custom menus and dboxes are:
Automatically built over the standard menus
Saved with the template and automatically built when importing the template

69. Linear Modes Control 1
Back

70. Linear Modes Control 2
Back

71. Linear Modes Control 3
Back

72. Cruise Control
In order to use Cruise Control it is necessary to create a construction frame in the car body, in the position where the traction force have to be applied. The construction frame have to be oriented with itz Z axis in the longitudinal positive direction of the car body. An output communicator of type Marker with matching name “traction” it’s needed to transfer the construction frames infromation to the TESTRIG when the vehicle is assembled.
Back

73. Track Property File (1)
Describe the properties of an ADAMS/Rail track. Different format exist, but only TRK_2 format is supported from the GUI. New format TRK_4 has been developed to allow the modeling of switch crossing and the introduction of guiding rails.
Information in the trk file consist of different blocks:
Global track info (Total length, format…).
Centerline layout (Curvature, cant, height…).
Irregularity data (Measured, analytic, … ).
Rail profiles.

74. Contact Configuration File
Defines the type and parameters of the contact model to be used
LIN (model check)
TAB (fast dynamics)
GEN (accurate dynamics)
QLT (linear analysis)
Can be different for every wheel/wheelset
Can be modified in ADM file

75. Switch Crossing (1)
Back

76. Switch Crossing (2)
Back

77. Switch Crossing (3) Next Switch Description Enhancements
Separate description of "rail" and "guiding rail" IDs in the rail configuration matrix of the TRK file (to allow profiles for rail and guiding rail to be defined at different sections)
Increase maximum number of points allowed for profile description; eventually, allow an automatic resampling of profiles to a number of points as specified by the user
Add the possibility of specifying, instead of a gauge value+vertical distance ( ), directly the distance between rail profiles reference systems (i.e. 1500)
Track gauge is now calculated only for the first profile pair
Add a parameter in the TRK file to specify the reference position of the switch along the track
Implement contemporary flexibility between track-ground and rail-guiding rail
Implement Unit independency in RPR files

78. Switch Crossing (3) Next
Example: Track with Guiding Rail, speed = 10 m/s
Flexibility between rail and guiding rail
25 m
40 m
45 m
54 m

79. Switch Crossing (3) Next
Example: Track with Guiding Rail, speed = 10 m/s
Flexibility between rail and guiding rail

80. Switch Crossing (3)
Next
Contact point number

81. Switch Crossing (3) Next
Example: Curve Track with Switch, speed = 20 m/s
Flexibility between rail and guiding rail
<training>\tracks.tbl\mdi_curved_switch_TRK4.trk
Use track graphic setting = “high”
85 m
125 m

82. Switch Crossing (3) Back
Example: Curve Track with Switch, speed = 20 m/s
Flexibility between rail and guiding rail