Getting Started

This guide will walk you through your first OpenSG analysis, from installation to running a complete blade segment analysis.

Prerequisites

Before using OpenSG, you should have:

• Basic knowledge of Python programming

• Understanding of finite element analysis concepts

• Familiarity with composite materials (optional but helpful)

Your First Analysis

Let’s perform a simple blade segment analysis using the provided example data.

1. Set up your environment:

   conda activate opensg_env
   cd /path/to/your/working/directory
   

2. Prepare the analysis script:

   Create a new Python file called my_first_analysis.py:

   from pathlib import Path
   import opensg
   import numpy as np
   from opensg.mesh.segment import ShellSegmentMesh
   
   # 1) Load blade mesh data and generate segment files
   blade_mesh_file = Path("data", "bar_urc_shell_mesh.yaml")
   
   # Generate segment mesh files
   opensg.io.generate_segment_shell_mesh_files(
       blade_mesh_file,
       segment_folder="segments/"
   )
   
   # 2) Analyze the first segment
   segment_file = Path("segments", f"{blade_mesh_file.stem}_segment_1.yaml")
   
   # Create segment mesh object
   segment_mesh = ShellSegmentMesh(segment_file)
   
   # Compute ABD matrices for the segment
   ABD = segment_mesh.compute_ABD()
   
   # Compute stiffness matrices using both beam theories
   timo_stiffness, eb_stiffness, l_stiffness, r_stiffness = segment_mesh.compute_stiffness(ABD)
   
   # Display results
   print("Timoshenko stiffness matrix shape:", timo_stiffness.shape)
   print("Euler-Bernoulli stiffness matrix shape:", eb_stiffness.shape)
   
   # Save results
   np.savetxt('segment_1_timoshenko.txt', timo_stiffness, fmt='%.6e')
   print("Results saved to segment_1_timoshenko.txt")
   

3. Run the analysis:

   python my_first_analysis.py
   

Understanding the Output

The analysis produces several types of stiffness matrices:

• Timoshenko stiffness matrix (6×6): Includes shear deformation effects

• Euler-Bernoulli stiffness matrix (4×4): Classical beam theory without shear

• Boundary stiffness matrices: For left and right segment boundaries