News and press releases May 2009
Plastic material behavior in a new version 4.xx of RFEM

High material stresses limited to a certain area often occur in steel constructions when using finite elements. Steel materials yield on these locations and transfer the stresses to adjacent areas.

Such a plastic material behavior cannot be represented by linear calculations. RFEM 4 allows to define the material behavior for surface elements in working diagrams or by means of plastic limit stresses. Now are available many new application fields where only plastic calculations are effective, especially with regard to economical designs.

To use this new option, the add-on module RF-MAT NL is required. It already includes common working diagrams for typical steel grades and is easy in use.

Calculation Process
The calculation is carried out in several load increments. After each iteration, the program checks if every element complies with the defined limit stress. If the limit stress is exceeded, the stiffness will be adjusted for the next iteration step. This procedure is repeated until the limit stress for all finite elements is no longer exceeded. Due to this adjustment of stiffnesses, the forces are distributed accordingly in the surface elements.

64-Bit Technology and Multi-Processor Support
As a result of the iterative calculation when using the function for plastic material behavior, the computing time may increase significantly depending on the entered model. That's why the new 64-bit analysis core represents such a great advantage. The main used memory can be extended considerably and the application of the faster direct equation solver is even available for bigger structural systems. As several processors are used automatically, the equation solving is accelerated even more remarkably.

New Functions
RFEM 4 offers even more new tools and improvements, for example a new interface to Open Office Calc, extrude functions for surfaces and solids from lines and the support of 3D mouse devices.

Find a detailed description of all new RFEM 4 features and enhancements in our Web site - see the links on the left.