CDH/AMLS and FastFRS new release

We are pleased to inform you that the upcoming CDH/AMLS Version 5.2 and CDH/FastFRS 2.2 (revision 179) is now available.

More information: Release Notes AMLS5.2r179 and AMLS AASI Guide

  • Fixes for some minor and very rarely encountered bugs
  • Computation time reduced for unusual cases in which the viscous damping matrix has many nonzero rows and columns, by improving the FastFRS strategy selection process
  • Several smaller performance enhancements
CDH/AMLS delivery database:
  • Implemented support for MSC-Nastran 2022.1, 2022.2 and NX/SimCenter-Nastran 2022.1
  • Implemented support for MSC Nastran Monte-Carlo simulation (Case Control MONCARL). MONCARL runs using AMLS and FastFRS will benefit significant reductions in computation time compared with standard MSC Nastran
  • Enhanced support for Nastran modal transient SOL 112
  • Bug fix for residual vector calculations for bush and damper elements
  • Bug fix for incorrect response results of SOL 111 in rare cases due to treatment of massless mechanism
  • Enhanced support for Nastran EIGRL with MAX option
  • Bug fix for NX-Nastran simulations using lumped-mass: PARAM,COUPMASS, -1
  • Bug fix for excessive information printed into f04 file in rare occasions
  • Updated support for CDH/VAO tool
Supported Nastran Versions
MSC: 2018.2, 2019.1, 2020.1, 2021.4, 2022.1, 2022.2
NX/SC: 12, 2020.1, 2020.2, 2021.1, 2021.2, 2022.1
CDH/AASI delivery database:
CDH Advanced Acoustic Solver Interface (AASI) is a new special DDB which offers a number of more advanced modules than the standard AMLS DDBs. The current initial release includes the  following features:
  • CDH/AASI-PEM is a new AMLS/FastFRS based interface to efficiently solve acoustic simulation containing porous elastic material (PEM) from MSC Nastran/ACTRAN
  • CDH/AASI-FastPPF is a new highly efficient algorithm for computing Panel Participation Factors (PPF)
NOTE: Use of AASI DDB requires a CDH/AASI license additional to AMLS/FastFRS licenses.
Supported Nastran Versions
MSC: 2021.42022.2
Key advantages of CDH/AASI
  • Up to 10x times reduced computation time compared to MSC Nastran (FastPPF).
  • Significantly lower disk space resource requirements
  • Performance benchmarks also show improved stability of AASI over the ACMS solver
The details of AASI DDB are available in the accompanying separate document CDH AASI Description and Guide.
CAUTION: End of support warnings
  • This is the last AMLS release that officially supports the RHEL/CentOS 6.x operating system by default
  • This is the last AMLS delivery database release that officially supports MSC-Nastran 2018, 2019 and SimCenter/NX-Nastran 12, 2019 by default.
  • In future releases only the latest sub-version of each Nastran release will be supported by AMLS. For example from MSC 2021.0 - 2021.4, only latest sub-version MSC 2021.4 will officially be supported. Please upgrade your Nastran versions accordingly.


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