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
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:
- Transfer drum receives newspapers and hands them over to a transmitter
- The transmitter hands the newspapers to a conveyor belt
- 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.
- 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: folding process
3 movies: part of an optimization process (geometry of counterwall)
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.
The animation shows an old simulation with the ALIEN program. It was presented by Fritz Leibundgut at the 8th Symposium on Detonation in Albuquerque, New Mexico, USA in 1985. 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.
sonar-3D simulation of a debris fence as used along borders of racing circuits to protect spectators. The impact was numerically simulated with sonar software in a very high level of detail. The element resolution of the wire-material was in order of magnitude of 100’000 objects.
The sonar chain module realistically simulates every type and geometry of a chain drive. The movie shows a toothed chain together with a simple, deliberately soft damper. The figure below shows a classic roller chain. The chain module provides special functions for the chain design. Simple chain applications can also be created by the user using sonar script macro language implemented in sonar-LAB.
This page reports about the Rockfall Barrier Project presented at the 50th US Rock Mechanics/Geomechanics Symposium held in Houston, Texas, 26-29 June 2016.
Abstract for the 50th US Rock Mechanics/Geomechanics Symposium held in Houston, Texas, 26-29 June 2016.
High-resolution numeric simulation of a standard rockfall test setup.
In cooperation with the company Geobrugg AG Switzerland, which specializes in security systems in the area of rockfall, we numerically simulated a standard test setup in high resolution in terms of the detailing with the “sonar” simulation software. The certified “Falling Rock Protection Barrier RXE-1000,” which has been intensively tested, experimentally measured and analyzed, formed the basis. The equipment consists in its core of several elastic ring-grid fields which, together with the suspension, can absorb energy of up to 1000 kJ. For the corresponding practical tests, we have detailed results for the movement behavior of the overall system and of various specific parts. Further, comprehensive measurements at various key positions were also taken during the practical trials. Slow motion recordings of the impact from various perspectives complete the base material.
This entire rockfall test setup was then modelled three-dimensionally at very high level of detail (down to the bolts, cables and wires) and simulated dynamically. A comparison of the results shows that in the future, we will be able to make very precise predictions about the dynamic movement behavior of complex systems in full detail as well as associated exact predictions of the physical loads. The match between experiment and theory will be documented in the next steps in a series of video clips that show comparative movement behavior as a function of time of various parts of the system.
The success of this dynamic analysis prompted us to develop a modular system that’s industry-specific in terms of simulation for the rockfall and security-system fields: in the future, this will allow for the creation and simulation of a model of a complete system within a reasonably short time.