# Archives

### Built-in meshes in FEniCS

In FEniCS, we can either work with the inbuilt meshes or we can also import the mesh file generated in another pre-processing tool as a xdmf format. In order to create inbuilt meshes, firstly, dolfin module is imported as: Matplotlib library is used to display the mesh plots. The different types of inbuilt meshes in […]

### Boundary conditions in FEniCS

Boundary conditions (B.C.) are constraints necessary for the solution of a boundary value problem. A boundary value problem is a differential equation (or system of differential equations) to be solved in a domain on whose boundary a set of conditions is known. Boundary value problems are extremely important as they model a vast amount of […]

### Effects of volume fraction and filter radius

This blog post explains the significance of the volume fraction and filter radius in the Topology optimization (TO). Volume fraction (volfrac) Volume fraction is the fraction of the original volume that the geometry of the optimized structure will have. Since, weight reduction is the major goal and density of the material remains constant therefore volume […]

### Obtaining volume, centre of gravity and inertia matrix from STL file

In order to get the details about the volume, centre of gravity and inertia matrix from the STL file of the geometry, we use the numpy-stl python library. It is an efficient and simple library to make work with STL files. The installation of this library is done using command:pip install numpy-stlAfter installing this package, […]

### Vector and Matrix Operations in PETSc (via petsc4py)

Through this post, you will learn how to do basic vector and matrix operations through petsc4py and how to solve a small linear problem using petsc4py. In addition, FEniCS PETSc formats and conversions are also briefly mentioned.

### Easy way to import mesh file of complex geometries from Ansys to FEniCS

Meshing is the most crucial part of finite element analysis. When the geometry is complicated, it becomes difficult to handle the mesh efficiently. It is always good to have an easy method through which we can import the mesh. In our lab, we mainly work with the open source finite element analysis software FEniCS. In […]

### Data Structure of FEM in FEniCS

Storing the element connectivity, element nodes, nodal degrees of freedom etc.. are of significant importance in any numerical package which implements finite element analysis. And this constitutes the data structure of FEM. In this post, I will try to explain how FEniCS does this.

### IGA 1: Why Isogeometric Analysis ?

Here I am trying to present an intuitive understanding about the need, importance and purpose of Isogeometric Analysis (IGA), which was developed in 2005 as an alternate/extension of classical FEM.

### Demystifying DOCKER – II : The FEniCS Workflow

Part I : Demystifying DOCKER â€“ I : The What and How Now that the idea and use of docker is clear, and that docker is installed and running; let us see how to make use of it to run FEniCS based codes in your system. FEniCS is a popular open-source computing platform for solving […]