FrontISTR v4.3 Release Notes¶

Introduction to the Minor Version Upgrade (VER.4.3)¶

PExProCS, LLC Kazuya Goto

Table of Contents¶

• Overview of the minor version upgrade
• Added features
  • Analysis function related
  • Partitioner related
  • Mesh / refine related
  • Linear solver related
• Bug fixes, and others
• Scheduled release

Overview of the Minor Version Upgrade¶

• Incorporation of code that existed in the development group but was not included in the public version
• Incorporation of function extensions and customizations developed in the Okuda Laboratory and its surroundings (including joint research)
• Implementation of (a part of) the features requested by users
• Fixing of defects

Added Features - 1: Analysis Function Related¶

• Support for mixed analysis of shell/beam elements and solid elements
  • (Details on the next page)
• Support for orthotropic materials in shell elements
• Support for layered shells
• Load FOLLOW function for large-deformation analysis
  • Added the parameter FOLLOW to !DLOAD (enabled by default)
• Support for beam elements in dynamic analysis
  • There are restrictions on the applicable load types (see the manual)
• Monitoring of multiple nodes in dynamic analysis
  • Specification by node group is possible
• Monitoring of nodal stress / nodal strain in dynamic analysis
• Application of window functions to the input fluid force in coupled analysis

Mixed Analysis of Shell/Beam Elements and Solid Elements¶

• Added beam elements (element type 641) that assign 3 degrees of freedom per node to 2 nodes, and shell elements (element types 761, 781)
• Since this is an experimental introduction, there is a possibility of specification changes in the future

Element type: 641
Nodes 1 and 2 have translational degrees of freedom, and nodes 3 and 4 have rotational degrees of freedom

Element type: 761
Nodes 1, 2, and 3 have translational degrees of freedom
Nodes 4, 5, and 6 have rotational degrees of freedom

Element type: 781
Nodes 1, 2, 3, and 4 have translational degrees of freedom
Nodes 5, 6, 7, and 8 have rotational degrees of freedom

Added Features - 2: Partitioner Related¶

• Substantial speedup
  • A speedup of about 150x in the case of partitioning a model of about 40 million nodes into about 20,000 domains
• Support for Metis Ver.5
  • Continued support for Ver.4 as well
  • When using MUMPS, caution is required because MUMPS supports only Metis Ver.4

Added Features - 3: Mesh / Refine Related¶

• Support for refinement of mixed element type models
  • However, mixing of element types with different nodal degrees of freedom is not possible
  • Support for refinement of plane models, and of shell/beam models, as well
• Support for interpolation based on the refinement information for input temperature data
  • For example, performing a heat conduction analysis without refinement, or with 1 refinement, and using its result as input to perform a thermal stress analysis with 2 refinements, etc.

Added Features - 4: Linear Solver Related¶

• Multi-color processing and hybrid parallel support in preconditioning
  • Through the cooperation of the Research Institute for Advanced Science and Technology (RIST)
  • (Details on the next page)
• Ordering for vector computers
  • Through the cooperation of the Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
  • Added the parameter USEJAD to !SOLVER
• For 3-degree-of-freedom problems, all combinations of preconditioners and iterative solvers are available
  • Iterative solvers: CG, BiCGSTAB, GPBiCG, GMRES
  • Preconditioners: SSOR, diagonal scaling, BILU(0), BILU(1), BILU(2)
• Matrix data dump function
  • Mainly for debugging
  • Added the parameters DUMPTYPE and DUMPEXIT to !SOLVER

Multi-color Processing and Hybrid Parallelism in Preconditioning¶

• Parallelized the matrix-vector product in threads using OpenMP
• Introduced multi-color ordering into the SSOR preconditioner and parallelized it in threads using OpenMP
• Tuned for the K computer and FX10

Figure: Thread parallel performance of the linear solver portion on the K computer (Data is from tutorial/02_elastic_hinge_parallel (4 domains))

Bug Fixes, and Others¶

• Fix of the Drilling DOF of shell elements
• Fix of the convergence criterion in nonlinear static analysis
• Fix of the time at restart in linear dynamic analysis
• Fix of the node number display in messages during coupled analysis
• Fix of the ILU preconditioner
• Fix of the communication routines of HEC-MW
• Avoiding defects during optimization by some compilers, etc.

Scheduled Release of Ver. 4.3¶

• Release timing: February 2014
• Version name: Ver. 4.3
• Scheduled release of the binary package for Linux
  • rpm (for Redhat-family distributions)
  • deb (for Debian-family distributions)
• Public site
  • http://www.multi.k.u-tokyo.ac.jp/FrontISTR/