FE Modeling and Modal Analysis of a Building — Lesson 1

This lesson covers the process of modeling a structure using Ansys software. The lesson begins with the creation of a G+3 building model, detailing the geometry and dimensions of the structure. The instructor then proceeds to demonstrate how to conduct a modal analysis using the software, which involves developing the mass and stiffness matrix, plotting the mode shapes, and observing the impact of an asymmetric plan building on the mode shapes. The lesson also covers the steps to assign different properties to the model, such as geometric properties and material properties. The lesson concludes with a demonstration of how to perform a model analysis, extract modes, and plot mode shapes.

Video Highlights

Explanation of the plan to model a structure using commercially available software - 0:34
Explanation of the geometry of the building, including the foundation, floor height, and asymmetry in the plan - 1:12
Discussion on the uniform beam section and column section throughout the building - 3:14
Explanation of the steps to follow in modeling the building, including defining the geometry, assigning properties, and meshing - 5:33
Demonstration of how to create the geometry of the building in Ansys software - 9:54
Explanation of how to assign the beam and column sections in the software - 13:00
Demonstration of how to copy the beams and columns to create the complete frame - 18:40
Explanation of how to assign the boundary conditions in the model - 22:11
Demonstration of how to do model analysis and extract some modes - 24:24
Explanation of how to plot the mode shapes and see the impact of asymmetric Plan Building on the mode shapes - 28:28
Demonstration of how to define the thickness for each floor slab and assign the material property - 34:28
Explanation of how to go for meshing and define the boundary conditions - 39:29
Demonstration of how to extract model frequencies and model shapes - 42:16
Discussion on how model analysis can help in checking whether the boundary conditions are properly applied - 46:57

Key Takeaways:

- Ansys software can be used to model structures and conduct modal analyses.
- The geometry and dimensions of a structure are crucial in creating an accurate model.
- Assigning properties to the model, such as geometric and material properties, is a necessary step in the modeling process.
- Modal analysis involves developing the mass and stiffness matrix, plotting mode shapes, and observing the impact of the structure's design on these shapes.
- The software allows for the extraction of modes and the plotting of mode shapes, providing valuable insights into the structure's behavior.