Software framework and limitations

Before using OpenSG, it is helpful to understand the software framework. OpenSG is a Python package, which contains several subpackages, listed below: Each subpackage contains modules that contain classes, methods, and functions. The classes used to generate blade mesh models and run structural analysis are described in more detail below, followed by a list of software limitations.

See API documentation for more information on the code structure.

OpenSG Subpackages:

core: Contains classes and methods for core computational functions including ABD matrix computation, beam model implementations, and stress recovery.
mesh: Contains classes and methods to define blade mesh models, segment meshes, and mesh data structures for both shell and solid element analyses.
io: Contains classes and methods for input/output operations including YAML file handling, mesh file generation, and data serialization.
utils: Contains utility functions for mathematical operations, finite element computations, eigenvalue solving, and mesh utilities for both shell and solid analyses.

Blade mesh model

The mesh subpackage contains classes to define blade mesh models, segment meshes, and their data structures. These classes are listed below: Blade mesh models can be built from YAML files or generated programmatically. The package supports both shell and solid element analyses for wind turbine blade structural analysis.

Mesh Classes:

ShellSegmentMesh: Class to define individual shell-based blade segments for efficient segment-by-segment analysis without requiring the full blade mesh.
SolidSegmentMesh: Class to define individual solid-based blade segments for 3D structural analysis of blade segments.

Core computational modules

The core subpackage contains classes and functions for the core structural analysis computations. These are listed below:

Core Analysis Classes and Functions:

compute_ABD_matrix(): Function to compute ABD matrices for composite laminates. Relates forces/moments to strains/curvatures in shell structures.
compute_timo_boun(): Function to compute boundary stiffness matrices for Euler-Bernoulli and Timoshenko beam theories on shell boundaries.
compute_stiffness(): Function to compute segment stiffness matrices using shell element formulations.
compute_timo_boun(): Function to compute boundary stiffness matrices for solid element analyses.
compute_stiffness(): Function to compute segment stiffness matrices using solid element formulations.
stress_recov: Module containing functions for stress recovery and post-processing, including local strain computation and stress analysis.

Utility functions

The utils subpackage contains utility functions that support the core analysis capabilities. These are organized by analysis type and listed below:

Utility Modules:

shared: Contains shared utility functions including nullspace computation, linear system solvers, and constraint handling used across both shell and solid analyses.
shell: Contains shell-specific utilities including local frame computations, strain measures, boundary condition handling, and shell element operations.
solid: Contains solid-specific utilities including 3D strain measures, stress computations, boundary markers, and solid element operations.
eigenvalue_solver: Contains eigenvalue solver utilities for advanced analysis including buckling and modal analysis capabilities.

Limitations

Current OpenSG limitations include:

TODO

Future work

TODO