DELTA JS was founded in 1997 by Dr. Joachim Schmied who earned his doctorate at the University of Darmstadt's Institute for Machine Dynamics in Germany. Before starting his own company he has gained 12 years practical experience in the turbomachinery industry.

Since its foundation the turnover of DELTA JS has grown continously and the company has achieved outstanding developments in the field of rotor dynamics resultung in the leading software MADYN 2000.



Foundation of DELTA JS.

1997 ...:

In the first years many demanding engineering projects were carried out in the area of blade vibrations and rotordynamics with the help of the general finite element program ANSYS ®, the machine dynamic program MADYN and MATLAB ®. Some of the work has been published (see technical papers).


Introduction of a rotordynamic analysis tool for systems with magnetic bearings, which has been licensed to the magnetic bearing pioneers in the turbomachinery industry.


Start of the project MADYN 2000 with the goal to develop a general rotordynamic software, which combines the power of DELTA JS’s existing tools with easy-to-use graphical user interfaces, an object-oriented data structure and state-of-the-art plots with clear and complete information about models and results.


General release of the rotordynamics software MADYN 2000, which has quickly found customers in the industry.


Winner of the Jorgen W. Lund memorial award for the best paper at the international IFTOMM rotordynamic conference.


First general rotordynamic seminar in Zurich. Since then it has been carried out twice a year.


Version 3.0 of the rotor dynamic program MADYN 2000 is released. It is another milestone regarding the userfriendliness of the program. 


Since then one to two new versions are released every year with new features (see release notes). Major features are listed below. 

Engineering projects are more and more focused on rotordynamics using MADYN 2000.


Implementation of nonlinear fluid film bearing analyses in MADYN 2000. 


Introduction of non-synchronous linear characteristics for tilting pad fluid film bearings in MADYN 2000.


Version 4.0 of MADYN 2000 with many features enhancing the modelling capabilities is released: Complex gears such as planetary gears with rotating or stationary planets as well as complex systems with nested shafts can easily be modelled.

Rolling element bearings with linear and nonlinear characteristics were introduced into the program.

The nonlinear features in the program were extended by nonlinear couplings and user defined nonlinearities allowing users to write their own nonlinear function in MATLAB code.


Coupled bearing support characteristics (e.g. of casings) can directly be imported to MADYN 2000 from ANSYS spm files as state space matrices.


Hot spot stability analyses were introduced in MADYN 2000 after carrying out many projects since the early days of DELTA JS with an add on to MADYN. This feature is very flexible and allows modelling and assessing the phenomenon in various components such as slip rings in generators, brush seals and fluid film bearings (Morton effect).


Seal analyses for the calculation of rotordynamic coefficients of seals in pumps, compressors and turbines were introduced into MADYN 2000.