R3 Technology, Inc

 

Technology

R3 Technology, Inc. also represents client products and capabilities.

BALLISTIC RESEARCH AND MODELING

R3 Technology has developed an analysis procedure for long rod penetrators that is based on using a specific method to estimate the effective flow stress of the target.  That flow stress is then used in both the WAPEN (Walker-Anderson Analytical Penetration Model) and a regression-based model.  The figure on the lower left shows both models compared to 425 test points that involved a variety of target materials, projectile materials, projectile length-to-diameter ratios varying from 1 to 32, and different projectile scales.  Analysis of the 425 points required several minutes on a laptop computer and the regression model took less than 1 second.  There is more than 3 orders of magnitude speed improvement, and important consideration when millions of shot lines must be analyzed.  The figure on the bottom right shows the regression model curves for various length-to-diameter projectiles and plots a number of data points against the curves.   There is still room for improvement and advancements.  R3 Technology hopes to continue this effort in the future.

R3 Technology, Inc. Ballistic Data System

R3 Technology, Inc. has developed a unique ballistics input and retrieval system.  It is based on open source software and can be used on Mac OS X, Windows, and Linux.   In addition to providing custom support, R3 Technology sells reports and/or data sets.   The data is being expanded every month.   Terminal Ballistics Data points for impacts against Semi-Infinite Target now exceed 5000 points.    V50, VS/VR, and other data sets are being created.  The system starts with raw data that can be entered via any text editor.   The raw files can be appended to other files permitting segregation of proprietary or classified data with merging as needed (and appropriate).   The raw data files can be used to generate HTML reports and plots as shown below, or the data can be exported into an XML schema for processing with other software.   Contact us for information on purchasing reports or XML data files.   We also support clients in porting their existing data to this system and creating specialized reports and analysis for things such as V50 testing.

As part of the DARPA AVM, R3 Technology supported SwRI in the development of blast loading models.   The model estimates loads from a buried mine and then develops a correction table that can be used with CONWEP to “correct” the CONWEP assumption of a spherical airburst to account for the blast load differences associated with a buried “pancake” shaped charge.   The figure above is an example of such a correction relationship.  There are a number of advantages to handling the blast loads in this manner, including computation speed and the ability to incorporate real world results without resorting to full-blown 3-d hydrocode modeling of the explosive loading component.  In many cases, the real concern is response of the vehicle.  R3 Technology hopes to extend this concept to include non-spherical explosives such as cylindrical charges or planar charges.  This technique also has the potential to enable a more accurate assessment of explosives other than TNT.  The CONWEP models are based on TNT and all other explosives are modeled by simply adjusting the energy (primarily weight) of the explosive of interest.  Unfortunately, TNT equivalency is not a single number.  It is different for pressure and impulse and it varies with scaled distance from the charge and other factors.  Using a technique like this permits corrections to the CONWEP estimates that more accurately reflect reality.

EXPLOSIVES RESEARCH AND MODELING

The figure below is a plot of the fit contained in the CONWEP model.  This is the model that is contained in programs such as LS-Dyna and Autodyn.  If one examines the software, you find that the model is based on high order polynomial regressions (sometimes order of 12 or 13) and that the coefficients often carry 10 or more decimals of “precision”.  This is actually a poor way to approximate these functions for several reasons.  First, it is not particularly computationally efficient.  Second, the functions “blow up” when you get too close or too far from and explosive charge as shown in the figure below.  R3 Technology has written a version of the CONWEP process that eliminates six of the CONWEP subroutines, runs faster, and avoids the problems associated with the polynomial regressions as implemented in CONWEP.