linearCSD

This project was developed by ATA Engineering as a way to solve for the linear structural response of a finite element model (FEM) under a long transient loading, typically from a compuational fluid dynamics (CFD) simulation. The project uses ATA's linearFSI library to provide the mapping and structural solving capabilities. Mass and stiffness matrices can be used from commercial structural solvers such as NASTRAN. The advantage of using this tool over directly using NASTRAN is that long duration loading time histories for large FEMs can approach hundreds of GBs in NASTRAN format. This can be problematic since NASTRAN reads this data into memory at the start of the simulation. This tool does not have the same limitation as the loading is read on a time step by time step basis.

Dependencies

This module depends on the linearFSI library developed by ATA Engineering. The linearFSI module itself depends on PETSc and MPI. A C++ compiler supporting the C++17 standard and cmake 3.10 or newer is also required.

Installation Instructions

First install the dependencies. For very large problems, it can be helpful to install PETSc with 64-bit indices. An example of configure options to build PETSc for use with linearFSI are shown below. On Cray systems, the additional arguments should be used to specify the C, C++, and FORTRAN compilers: --with-cc, --with-CC, and --with-fc.

./configure --prefix=/path/to/install --download-fblaslapack=yes --download-superlu_dist=yes --download-scalapack=yes --with-64-bit-indices --with-debugging=0  --with-pic=1 --with-cxx-dialect=C++11 --with-shared-libraries=1 --download-hdf5=yes --with-mpi-dir=/path/to/mpi --download-hdf5-configure-arguments=--enable-fortran=no

The installation follows the standard cmake process. It is recommend to build from outside the source directory. The example below shows how to build the code. When installing on Cray systems, the additional flag -DCRAY should be passed to cmake during the configuring process.

cmake -DCMAKE_INSTALL_PREFIX=/path/to/installation -DCMAKE_BUILD_TYPE=release -DLINEARFSI_LIB_DIR=/path/to/linearFSI/lib -DPETSc_DIR=/path/to/petsc -DMPI_DIR=/path/to/mpi /path/to/source
make
make install

To Do

• Add examples
• Add unit tests
• Improve documentation