Due to the increasing de mand for ur­

ban transport sys tems manu facturers

are con tin ually working to optimise

pass enger ca pa city and comfort and

to in crease travelling speeds. Virtual

tes ting systems which minimise de ve­

lopment time and enable opti misation,

not only significantly reduce costs,

but also quicken the time to market

­ advantages ne ces sary in today’s

competitive mar ket.

The role of structural dynamics in con­

nection with vehicle running dy namics

is increasingly important due to the

ever more common use of lightweight

materials and con structions. A virtual

tes ting system must al so therefore be

able to accurately simulate elas tic be­

haviour.

Work has been carried out by SIE MENS

in order to optimise the ride comfort of

future metro trains by numerical simu­

lation using SIM PACK. Additionally, the

soft ware tools I­DEAS and ABAQUS

have been used. A data base has been

built in order to simp lify and speed up

the de ve lop ment process.

SIMPACK´s database structure enables

quick and easy assembly of dif erent

train configurations for virtual test­

Modeling and Simulation of the New Metro Train for Vienna with SIMPACK Wheel/Rail Using Flexible Car BodiesDesigning the Metro for Vienna, combined both multi­body and finite element modelling in the entire development process. The car body models were imported from ABAQUS into SIMPACK, taking advantage of SIMPACK‘s ability to accurately tune the FE model for use within a multi­body system, with the use of frequency response modes. SIMPACK‘s use of substructuring a complete railway model allows an efficient way of investigating the behaviour of diferent vehicle designs, reducing model set­up time. The project was carried out with the help of INTEC‘s consultancy branch.

ing. The database fol lows a modular

concept, which con sists of all the

components ne cessary for accurate

simu la tions to be selected and pulled

together in to a main model for virtual

tes ting. Alterations made to any com­

ponents (i.e. sub struc tures like rigid or

as flexible modelled car bodies, cou­

plers, driving bogies, trailing bogies,

etc.), auto matically trans fer and thus

up date the train­models of interest.

Each compo nent has been tested and

valida ted before being en tered into

the database.

This concept allows a large num ber of

diferent vehicle con figura tions to be

easily handled.

The car body shells of the metro train

for Vienna are made out of large alu mi­

nium extrusions wel ded to gether and

has been mo delled using finite element

soft ware. The ceiling frame, floor struc­

ture, win dows and seats have also been

modelled as elastic components. The

car body of the in ter me diate car con­

sists of ap proxi mately 369 000 degrees

of free dom. These de grees of free dom

have been re duced using the Guyan

conden sa tion method. To enable short

com pu ta tion times all mode shapes

Page 7Page 6 News 1/2001

New Metro Train for Vienna*

The Virtual Intermediate Car*

The Diagonal Distortion*

Appl icat i o ns

Dr. Anton StriberskySIEMENS TS HR, Vienna

above 30 Hz have been neg lec ted. In

order to improve the ac cu r acy of the

particular modes, which de scribe local

deflec tions, the SIMPACK pre­proces sor

FEMBS allows to select fre quen cy re­

sponse modes which are sig ni ficant to

the coupled move ment and frequency

range of in ter est. Time consuming

modifi cations to the FEM model and

un ne cessary con straint modelling are

not re quired. The entire elastic bo dy

has been reduced to 12 eigen modes

and 27 frequency response modes to

accurately de scribe the flexibility up

to 30 Hz.

Elastically mounted equipment at­

tached to the car body has been mod­

elled with rigid bodies con nec ted using

force elements. In order to ensure the

validity of the model for the flexible

structure, a comparison was made

bet ween an ABAQUS FEM model (i.e.

including flexibly mounted e quip ment)

and the SIM PACK model using the re­

duced FEM model.

The results from the SIMPACK simula­

tion correlate well with those obtained

from the mea surements taken from the

proto type vehicle for both the lateral

and vertical ac celerations (rms). The ac­

celerations were mea sured on the floor

at the car centre close to the side wall.

Having developed the database and

having validated the entire virtual train,

diferent con fi gura tions can now be

assembled quick ly and easily for use

in dy namic analyses and optimi sa tion

studies.

Not only can development costs be

dra ma tically reduced, but the com­

pany’s expertise and know­how can

be continually col lected and stored in

an ever ex pan ding database, on hand

for the current and next generation of

pro ducts.

A similar article, which points out

additional aspects of this project can

be obtained from INTEC: Structural

Dynamics of Rail Ve hicle Systems: A

Virtual Systems Approach, Civil Comp

Ltd., Edin burgh, Scotland 2000. All the

fi gures on page 6 and 7 are taken with

the kind permission of Civil Comp Ltd.

Page 7Page 6 News 1/2001

* all figures are from the article “Structural Dynamics of Rail Vehicle Systems. A Virtual Systems Approach” by

A. Stribersky, F. Moser and W. Rulka, published as pages 29 to 36 inclusive in “Developments in Engineering

Computational Technology”, edited by B.H.V. Topping (CIVIL­COMP LTD)

Comparison Between ABAQUS FEM Model and Reduced SIMPACK Model*

Interior Design of the Metro Vehicle*

Finite Element Model of the Metro Vehicle*

Comparison of Simulated and Measured Accelerations *