The Compression Tool for Simulation Results

In 2014 CDH AG acquired marketing, sales and support rights from SIDACT GmbH to distribute FEMZIP products in Japan and USA. FEMZIP products offers advanced numerical algorithms to efficiently compress result data of leading industry FEM solvers, including MSC.NASTRAN, NX-NASTRAN and ESI PAM-CRASH.



Reduced Archive Size
If all simulation data is compressed only a fraction of the storage is required. Storage and backup capacities can hold more simulation results. Hence, investments in the growth of storage and archive infrastructures can be avoided.


Shorter Data Transfer Times
Transferring result data across computer networks can be very time consuming. Transmission speeds are limited by the available network bandwidth. Since compressed simulation results require significantly less storage they can be transferred in a fraction of the time required for transferring uncompressed results.


Quicker Data Loading
Reading data into post-processors can be a time consuming task as well. If data storage is provided on file servers, compressed data can be read directly into post processors significantly quicker due to the faster data transfer. In some cases load times can even be improved when reading from a local hard drive.

While providing these benefits FEMZIP is made to fit into the workflow used by engineers. It is designed to be integrated into batch processes to enable automated compression immediately after the simulation process. This way the engineer can benefit from data compression without the requirement of manually operating FEMZIP. Furthermore, on-the-fly decompression functionality of FEMZIP is integrated into common post-processing tools to make direct access to the content of compressed files possible. Hence, it is often not necessary to retrieve the original data formats with the stand-alone decompression tool FEMUNZIP to view the compressed results.


Crash-simulation is a standard CAE application in the automotive industry. The effort of improving car safety is accompanied by large numbers of simulations performed on a daily basis. As a result vast amounts of simulation data are continuously produced. With FEMZIP for CRASH we offer a series of data compression solutions specially designed for commonly used crash-codes. FEMZIP versions are available for PAM-CRASH, LS-DYNA and RADIOSS result files.


Test results by Volkswagen AG for PAM-CRASH output file (DSY) of a simulation using a car model with 1031990 nodes.

Typical crash result files can be reduced with FEMZIP by about a factor of 10. This reduction leads to considerably lower storage requirements, significant shorter data transmission and quicker data loading. The ladder can be experienced with a variety of post-processing tools that support the compressed data format of FEMZIP. To improve the experience of working with FEMZIP compressed files, we have worked together with post-processor developers to enhance the integration of our decompression technology. Today, a large number of post-processors support our format, so that working with compressed files has become easier than ever before.

ProductsSupported Post-Processors
FEMZIP-P (PAM-CRASH) ESI Visual Environment
FEMZIP-R (Radioss) LS-Prepost
Altair Hyperview / Hypergraph
Beta ?ETA
Oasys D3PLOT

For noise vibration harshness (NVH) analysis results are often calculated for a large number of modes. The emerging data of a single simulation usually comprises several GBs of data. For collaborating engineers at different sites that have to exchange this data across telecommunication networks data transfer can become a bottleneck in their workflows. Transfer times can be reduced significantly by employing FEMZIP. Instead of waiting for hours FEMZIP compressed NVH results can often be transferred in a matter of minutes. Consequently, a more fluent collaboration is possible. FEMZIP-N supports MSC NASTRAN and RASIOSS results stored in the OP2 data format.


Test results for Nastran OP2 file: Car model with 1428719 nodes. Solution Type 103, 51 modes


Test results for Radioss OP2 file: Car model with 1026074 nodes. Solution Type 101, 29 modes.

While very efficient compression is obtained for standard sized models, even larger compression factors are possible for results with hundreds or thousands of modes. In some cases it is possible to reduce result files by a factor of 40.

ProductsSupported Post-Processors
(NASTRAN / Radioss OP2) Beta ?ETA


Christian Pieper

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