Rockfall Barrier > continue

As a continuation of the simulation project, as shown in 2016 at the ARMA Symposium in Houston TX, USA, new scenarios with different impact positions of the falling weight are presented here.

impact near supporting beam
central hit on beam
lateral hit on beam

The purpose of these simulations is to prove that this protection device will withstand even if the drop weight falls off the center of the field.


crushing tubes and extruded profiles

This sonar-simulation shows a crushing process of an aluminum tube. The piston is accelerated by a strong force while its max. speed is limited to 10 m/s. Aluminum tube properties are:

tube diameter = 66 mm
tube thickness = 0.6 mm
tube length = 132 mm (L/D ratio = 2)
material model with isotropic hardening

The next 3 movies show the same simulation with different aluminum sheet thickness.

sheet thickness = 0.3 mm

sheet thickness = 0.2 mm

sheet thickness = 0.1 mm


The Creation of the Moon

The most likely theories state that the Earth’s moon was created by a collision of the Earth with another planet. The other planet was about the size of Mars and hit the Earth in a grazing collision. Some of the material that was thrown up fell back to the Earth. Other material got into Orbit around the Earth and created the moon. It is also possible that the left-over material from this collision formed the asteroid belt. This expanse of rubble is located between the paths of Mars and Jupiter. The planet that collided with the Earth destroyed itself by doing so. Studies of rocks from the moon have especially supported this theory. If it’s true then the moon should be made out of material from two planets. There must also be a lot of material from the other planet on the moon.

A slightly modified simulation in closer view and higher Resolution
(half particle size = 8-fold number of particles = 64-fold calculation time)

The movies show double collisions. What exactly happens in a collision strongly depends on the flight path parameters


Low Voltage Switches


Elektrische Schalter sind hochdynamische Apparate. Der Ausschaltvorgang, welcher durch verschiedene Einflussgrössen mechanischer oder elektrischer Art ausgelöst werden kann, muss in der Regel so schnell als möglich geschehen. Die Physik spielt dabei eine zentrale Rolle. Gewisse Hersteller socher Schaltelemente haben deshalb erkannt, dass der Einsatz einer Simulations Software wie sonar nicht erst vor dem Entwicklungsabschluss oder beim Auftreten von Störungen zum Einsatz kommen sollte, sondern bereits von Anbeginn weg, wenn die Mechanik des Schalters konstruktiv ausgelegt wird. Durch Parameterstudien im Sinne von Variationen der Hebelmechanik, der Massenverteilung oder der Mechanismen selbst werden z.T. ganz neue Ideen geboren. Und jede Idee, wie abwegig sie vorerst erscheinen mag, kann in Simulationen ohne weitere Risiken und Konsequenzen getestet werden.

Fig. Vergleichende Simulationen von Variationen an einem einheitlichen Basisschalter

Fig. Simulationen an Schalterkombinationen mehrerer Schalter welche hier am Bildschirm in der 3. Dimension, also senkrecht zur Bildschirmebene, aneinander gefügt sind.





Schwingungsanalyse an einem Hochstromschalter

In sog. Hochstromschaltern können z.T. zusätzliche elektrodynamische Kräfte ins Spiel kommen welche sich in Form erheblicher zusätzlicher Reibungen äussern. Dank den vielen Möglichkeiten in sonar, solche externe Kräfte während einer Simulation in Kontrollsystemen kontinuierlich zu berechnen und in die laufende Simulation einfliessen zu lassen, sind sehr realistische Analysen möglich.

Fig. Ausschnit aus der Mechanik eines Hochstromschalters

Fig. Ein Schalter etwas anderer Art






sonar-3D has a powerful calculation kernel for the interaction control between objects (sonar-3D DLL). This is demonstrated in this example of a tobacco heap. Each individual tobacco fiber is – like a leaf spring – a flexible structure with a bending stiffness of normal tobacco fibers and interacts over its entire surface with all its neighboring fibers.


Simulation eines kompletten Uhrwerks

Ganze Uhren oder Hemmungen in Uhren sind ideale Anwärter für Simulationen mit der Software sonar-2D. Durch ihren konstruktiven Aufbau in ebene Schichten können Hemmungen in der Regel ohne Einbusse hinsichtlich Realitätbezug mit der zweidimensionalen Software simuliert werden.

Die Software simuliert genauestens die geometriebedingten Kontakabläufe im Bereich der eigentlichen Hemmung unter Berücksichtigung der physikalischen Trägheiten, Reibungen, Prellungen, Schwingungen, Vibrationen und externen Kräften wie Gravitation, usw.

Durch ihre Realitätsnähe sind vergleichende Simulationen unterschiedlicher Hemmungen möglich. Die Software ist in der Lage sowohl die absolute als auch die relative Energieeffizienz zu messen

Auch funktionelle und energetische Unzulänglichkeiten hypothetischer Hemmungen können analysiert und ausgewertet werden. Neue Vorschläge von ‘Erfindern’ für bessere Hemmungen werden von sonar-2D in der Regel bereits bei der simulationstechnischen Analyse als unrealistisch offengelegt.








Cable Failure

Cable Failure


Using the example of a lift cable consisting of a total of 163 wires and different wire diameters, a so-called tensile test is carried out. A cable end is exposed to an increasing load until the breaking point of the cable is exceeded. The film shows the process in strong slow motion. The simulation used a material model with isotropic hardening in the strain region, a yield limit of 4.0% and a shape change hypothesis according to Rankine.

Fig. cable cross section

Fig. a snapshot of the tensile stress in the cable

Printing Machine

sonar-2D has been used extensively to solve problems in the printing press industry. The following examples show 6 movies of 4 problems on a newspaper press machine:

  1. Transfer drum receives newspapers and hands them over to a transmitter
  2. The transmitter hands the newspapers to a conveyor belt
  3. Simulation of the folding process on a newspaper and handover to the so-called ‘Bermuda Triangle’ – a term that comes with several manufacturers of printing machines.
  4. Example of an optimization of the geometry of the counterwall in the so-called ‘Bermuda Triangle’ with the objective of handover the newspaper as flat as possible.

movie: Transfer drum

movie: Transmitter

movie: folding process

3 movies: part of an optimization process (geometry of counterwall)

sonar History

All the time, numerical simulation was our passion


sonar-3D reached a quality, stability and performance to simulate complex models with up to 100’000 objects.


In 2009 the development of our new 3D-simulation software sonar-3D made it feasable to simulate a copper or steel cable with a resolution down to the wire level or a yarn with all its fibres.


A few years later, it was already possible to realistically simulate a mechanism with the complexity of a complete mechanical watch with the SILUX software. In this simulation, even the physical simulation of the individual interacting cogs was calculated in detail. The illustration shows part of a model of a “Reverso” watch made by Jaeger-LeCoultre.


The continual physical simulation of a simple watch mechanism proved that a general, technical simulation program for a multi-body dynamic system was fundamentally possible. This eventually led to the development of SILUX software and its successor sonar-2D.

 before 1994alienanimation

The animation shows an old simulation with the ALIEN program. It was presented at the 8th Symposium on Detonation in Albuquerque, New Mexico, USA. The simulation shows the initiation of the main charge of a 35 mm air-defence shell through a booster charge. At the time, the simulation required 8 days CPU calculation time on a VAX 11-780 computer. Today, this problem can be solved on a standard personal computer in a fraction of an hour. Today ALIEN is integrated in sonar-2D software.