Highspeed Dynamics


Systems undergoing dynamic loading, such as an earthquake or explosive blast, naturally dissipate vibrational energy over time. For a dynamic numerical analysis, some form of artificial damping needs to applied so that the model should reproduces such energy losses.

FLAC3D 9 introduces Maxwell dynamic damping for time-domain seismic deformation analyses. FLAC3D models using Maxwell damping can be 10-200 times faster, and as accurate, than those models using Rayleigh damping. With Maxwell damping, large, 3D site response and soil-structure interaction are now practical to analyze.


For example, the FLAC3D 9 model shown below simulates a caisson foundation, using shell elements, which is much stiffer than the surrounding soils. This model consists of nearly 100,000 zones and over 15,000 structural shell elements.

An analysis of a 30-second earthquake input time history for this model, using a typical computer, requires approximately 10 hours using Maxwell damping, whereas it would require more than 50 days when Rayleigh damping was used. In other words, using Maxwell damping, the calculation is 120 times faster for this model. This is a substantial benefit for similar practical projects.

FLAC3D soil structure interaction model subjected to an earthquake. Displacements are exaggerated using a deformation factor of 20,000x.


The Ramberg-Osgood model has also been added as one of several hysteretic damping calculations for dynamic modeling. The Ramberg-Osgood hysteretic model overcomes the shortcoming of overly large damping at large shear strains by other available hysteretic damping models in FLAC3D. Hysteretic damping may be preferred where: (1) designers and licensing authorities do not accept fully nonlinear simulations and (2) faster model run times are desired, as additional damping (e.g., Rayleigh) may not be necessary.

Latest News
  • Thank You to our Summer Interns ITASCA Minneapolis is lucky to have welcomed nine amazing and dedicated summer interns in our...
    Read More
  • Introducing IMAT: Transforming Mining Analysis Solutions Introducing IMAT: Revolutionizing mining analysis with advanced geotechnical modeling and seismic data integration....
    Read More
  • ITASCA Unveils XSite 4.0: Advancing Hydraulic Fracturing Simulation ITASCA announces the launch of XSite 4.0, a groundbreaking advancement in hydraulic fracturing simulation software....
    Read More

Upcoming Events
26 Aug
FLAC3D V9.1 and Griddle V2.0 2024
... Read More
17 Sep
Held once every four years, MassMin unites global experts to tackle the industry's most pressing sustainability challenges. MassMin pro... Read More
22 Sep
SMRI Fall 2024
The Solution Mining Research Institute (SMRI) was established in 1965 as a venue for the solution mining and underground storage indust... Read More