pyJive

A python Finite Element library inspired by jive

Contributors

Iuri Rocha (i.rocha@tudelft.nl)
Frans van der Meer (f.p.vandermeer@tudelft.nl)
Anne Poot
Jelle Knibbe
Andres Martinez Colan

Philosophy

The library works with modules and models. Modules define the flow of the program, e.g. the solvermodule defines that a matrix and RHS vector need to be assembled after which a linear system of equation is solved. Models define how the main task are implemented, e.g. the elasticmodel that assembles the stiffness matrix for an elasticity problem.

Modules and models interact through the take_action function.

Input

Problem-specific input is defined in a properties file (with .pro extension). The repository contains sample input files.

Important classes

dofspace: degree of freedom management to provide mapping between dof index and node number and dof type
shape: abstract base class that defines the element type
constrainer: class that handles the application of constrains to the as-assembled stiffness matrix and force vector, and returns constrained versions of them ready for solving

Implemented shapes

Generates shape functions, gradients and weights. The following classes are implemented in paramshapes.py:

Tri3Shape: 3-node linear triangular shape
Tri6Shape: 6-node quadratic triangular shape
Quad4Shape: 4-node linear quadrilateral shape
Line2Shape: 2-node linear line shape
Line3Shape: 3-node quadratic line shape

Utility functions

declare.py: this is where the available models and modules are defined (this is needed to be able to construct a problem dependent module-model scheme)
runPro.py: simple master script that parses an input .pro file through proputils.py and calls main.py
main.py: defines chain of modules

Modules

Preprocessing

initmodule: initializes globdat object with global data including mesh and nodegroups. Accepts mesh files from gmsh and meshio as well as manually generated mesh files (see syntaxis on initmodule.py)

Main solver routines

linbuckmodule: solves eigenvalue problem for linear buckling analysis
solvermodule: assembles and solves system of equations on a given number of steps
nonlinmodule: newton-raphson solver for nonlinear system of equations
modeshapemodule: solves eigenvalue problem for free vibration

Postprocessing

vtkoutmodule: writes output to vtk file (compatible with paraview)
viewmodule: visualization of full field data
frameviewmodule: dedicated postprocessor for frame structures
loaddispmodule: stores load displacement data for specified nodegroups in globdat
graphmodule: plots data for instance data stored by loaddispmodule
outputmodule: writes primary unknown to file

Models

multimodel: provides a fork from a single model into a list of models
elasticmodel: assembles matrix for elasticity problem
barmodel: assembles matrix for a 1D bar problem
timoshenkomodel: assembles matrix for a Timoshenko beam problem
framemodel: assembles matrix for frame problem with extensible Timoshenko elements
dirimodel: implements Dirichlet boundary conditions
neumannmodel: implements Neumann boundary conditions

ritukeshbharali/pyJive