CDH-AG

Highly Efficient Modal Frequency Response Analysis

CDH/FastFRS is a Fast Frequency Response Solver which drastically accelerates MSC Nastran, NX Nastran, Altair OptistructTM, ESI VPS and ADVENTURECluster modal analysis.

Why onother Solver?

The availability of the Automated MultiLevel Substructuring (AMLS) software has enabled frequency response analyses using very large FE models and many modes. With certain simplified types of damping the resulting modal matrices can be solved easily.

However, modeling damping accurately can make modal frequency response problems computationally very expensive to solve. Accurately modeled damping results in matrices that are fully populated rather than diagonal. The modal frequency response then requires a matrix factorization at each frequency. The time required for each factorization is proportional to the cube of the number of modes, so analyses up to higher frequencies, for which many modes are required, become extremely expensive.

FastFRS (fast frequency response solver) addresses this issue by performing only one numerical operation whose cost is proportional to the cube of the number of modes, rather than one such operation at each response frequency. The solver obtains an exact, direct solution, rather than an approximation for which the user specifies a cutoff frequency, a convergence tolerance, or some other parameter requiring special expertise or instruction. As a result, FastFRS is very reliable and easy to use.

Implementation

Interface to MSC.NASTRAN, MD.NASTRAN, NX-NASTRAN and ALTAIR RADIOSS software, so that it can be used in industrial vibration and acoustic analysis.

CDH/FastFRS can be used in modal frequency response (NASTRAN SOL111) analysis and requires a minimum of effort on the part of the user to take advantage of drastic reduced job turnaround times.

Performance

CPU

CDH/FastFRS typically reduces the amount of CPU time required by a minimum factor of about 10 to 30.

* Model Size: 16 Mio DOF, 7406 Modes, Modal Frequency Response Analysis. All calculations are carried out using NASTRAN on a Linux 64 compute server (8 cores).

I/O

A more important reduction, in many cases, is the reduction in data transferred (I/O) by a factor of about 40 to 60.

* Model Size: 16 Mio DOF, 7406 Modes, Modal Frequency Response Analysis. All calculations are carried out using NASTRAN on a Linux 64 compute server (8 cores).

Accuracy

Advantages

  • The combination of AMLS and FastFRS allows the user to solve NVH problems to even higher frequencies.
  • With many modes, diagonalizing the modal FR problem is much more efficient than solving a fully coupled problem at each frequency.
  • The result is the most efficient solution method available with no truncation error.

System Requirements

OPERATING SYSTEM

Linux64 (x86_64)

SUPPORTED SOLVERS / SOFTWARE

MSC.NASTRAN
MD.NASTRAN
NX NASTRAN
Altair RADIOSS
Altair OPTISTRUCT

Note:
MSC.NASTRAN and MD.NASTRAN are proprietary products of MSC.Software Corporation. NX NASTRAN is a proprietary product of Siemens Product Lifecycle Management Software Inc.. Altair RADIOSS and Altair OPTISTRUCT are proprietary products of Altair Engineering, Inc..

TRIAL INSTALLATION

You can try this product free of charge for 30 days.

Request trial license

Have any questions about this product? Feel free to get in touch.

Contact Person: Christian Pieper
Telephone:  
E-Mail: