The Nastran HDF5 Result Database (NH5RDB)

Introduction 

The NH5RDB is a Nastran database file in Hierarchical Data Format (HDF5). The database organizes Nastran input and output data in a hierarchical structure. Nastran data is stored as dataset in database and can be accessed through standard HDF5 APIs or third party packages in multiple programming languages. The main features of NH5RDB include:

 ? A data type schema in XML defines database structure and datasets formats. 

? All main Nastran input and output data are covere 

? Supported by multiple Nastran solutions. 

? Optional output by MDLPRM parameter and system cell. 

? New DMAP modules to write Nastran data blocks in database. 

 ? An open format and multiple programming language support for data access. 

The NH5RDB supports wide range of data types and is capable of defining complicated data structures. In the database, the datasets are stored in a hierarchical structure, making it easy to add, remove or update datasets in applications. The database supports high precision, compression and unlimited amount of data. Its open format and multiple programming languages support make it ideal for FEA applications. 

The NH5RDB has modal input and result data. It organizes data in groups and datasets. The input data has groups like NODE, ELEMENT, CONSTRAINT, LOAD, etc. The result data includes ACOUSTIC, CONTACT, NODAL, ELEMTENTAL and other groups. In each group, data are stored in table like datasets. A dataset in NH5RDB is defined by a compound structure with member fields. For example, the GRID dataset in the input NODE group has fields for grid number and coordinates, it will have all grid point definitions from the modal. The DISPLACEMENT dataset in RESULT group has fields for displacement components and will contain all nodal displacement from all output steps. A dataset in NH5RDB could be identified by its dataset name and group path defined in the schema.

 There are some options available for NH5RDB output. The HDF5 parameter in MDLPRM is used to control NH5RDB generation. By default, NH5RDB will not be generated. Data compression can be selected for NH5RDBB. Also the input data can be selected not to be included in NH5RDB by HDF5 parameter options. 

Since HDF5 is an open format architecture. The NH5RDB data can be accessed by standard HDF5 library APIs or third party packages. Multiple programming languages, such as C/C++, FORTRAN, Python and Java, are supported. The example section gives examples of NH5RDB data access in multiple languages.