In Sweden modeling of railway vehicles in computers started at ASEA in 1971 with a linear program in the frequency domain.
In 1973 the development of the first nonlinear time integration program started.
The program was a code with specific-generic-structure.
The program consists of two parts;
one taking lateral motions into account,
and the other taking vertical motions into account.
These programs were developed together with the first high speed test train, the X15, in Sweden.
The Rc4-locomotive was designed in 1975 for the Swedish State Railways,
and was the first project in which ASEA used the above mentioned computer programs.
Since then every new vehicle delivered by ASEA, and later ABB, has been designed by using these programs,
including the tilting high speed train, the X2000.
The first official presentation of our tool was made by Evert Andersson in Graz 1977.
The name of the presentation was "Simulation von Spurkräften und Laufeigenschaften",
ZEV-Glasers Annalen 101 (1977) Nr 8/9, p.339-347.
Evert Andersson is today the professor in Stockholm at the Royal Institute of Technology,
Department of Railway Technology.
Development of the simulation programs continued with several releases throughout the1980's,
but in 1992 the development of a new three-dimensional calculation program started.
At the same time the development of the dynamic package moved into a new company called DEsolver,
which has the sole task of developing and supporting the program package.
This new three-dimensional, general computer code,
together with all earlier pre- and post-programs became in 1993 the new railway vehicle analysis tool called GENSYS.
The main calculation programs in GENSYS are called QUASI, MODAL, FRESP and TSIM. Where:
Program QUASI performs quasistatical analysis.
Program MODAL performs modal analysis.
Program FRESP performs frequency-response analysis.
Program TSIM performs time integration.
All the four major calculation programs are very general in their basic concepts.
All information describing the problem is stored in only one array,
in order to give the user access to all data during the calculation phase.
This is mainly done to let the user easily design his/her own active suspension components,
where the user can have interest in reading any arbitrary variable describing the input data model.
The user also has the possibility to change all variables in the input data model during the calculation phase.
The coupling between wheel and rail is described in a user-defined element where the creep-forces between
wheel and rail depend on creep, spin, contact force and shape of the contact surface.
GENSYS consists of several preprocessors,
in order to generate safe and simple input data for the main calculations programs.
The preprocessors are divided into the following parts:
| TRACK | A group of preprocessors generating track irregularity files. |
| KPF | A group of preprocessors generating functions of the wheel-rail geometrical properties. |
| MISC | A group of miscellaneous programs. |
| NPICK | Update the input data model with flexible modes from FEM-analysis. |
| OPTI | A program generating a sequence of calculations in any other program in the GENSYS package. |
| PREDAT | A fast input data generator for the four programs QUASI, MODAL, FRESP and TSIM. |
In the GENSYS package two powerful postprocessors are included.
The names of the postprocessors are GPLOT and MPLOT.
The GPLOT program is a 3-D program viewing the vehicle from a point chosen by the user.
In addition to the geometry plot, GPLOT can animate results from MODAL and TSIM.
The MPLOT program consists of two major parts: plotting and postprocessing.
The plotting part generates 2- and 3-D plots of curves and scalars.
The postprocessing part in MPLOT consists of the following functions:
algebraic operations, filtering operations, Fourier transform operations,
several ride comfort assessments and different statistical evaluation methods.
MPLOT can handle results from several result-files simultaneously.
The program package has continuously been validated by ASEA, later ABB and Adtranz Sweden, for different kinds of railway vehicles. Validation of the program package has also been carried out for the following benchmarks: IAVSD Benchmark #1, IAVSD Benchmark #2, ERRI B 176/DT 290 and the Manchester Benchmarks to appear in the supplement of Journal of Vehicle System Dynamics, April 1999. The development of GENSYS is carried out by DEsolver partly in cooperation with the Technical University of Stockholm (KTH).
GENSYS is available from DEsolver under a license agreement. The annual license fee of the package includes full telephone support, access to the GENSYS USER GROUP, an introduction course, maintenance and updates. Installations exist on the following platforms: HP workstations running under HP-UX, IBM workstations running under AIX, Sun workstations running under Sun_OS and Solaris, Silicon Graphics INDIGO workstation and PC-computers running under Linux.