geometries.md

Fetching new geometries

README

Table of Contents

• Fetching new geometries
  • Import a geometry (importGeometry)
  • Modify an existing geometry (modifyGeometry)
  • Generate a new geometry (generateGeometry)

Import a geometry (importGeometry)

One can import a geometry.structure from a STL or a STEP file using the importGeometry Matlab built-in function.

Example :

geometry.structure = tools.importGeometry('Cube.stl');
geometry.exposed_faces = 6
geometry.nbr_cavities = 5

Generate a new geometry (generateGeometry)

One can generate new cubic or ellipsoidal geometries. The function generateGeometry returns a geometry structure, with the following arguments :

Arguments :

The radius of the spherical heterogenous cavities is randomized between min_radius and max_radius. Set nbr_cavities to 0 for homogeneous geometry.

Fields	Type	Description
shape	string	'cube' or 'ellipsoid'
unit	array (double)	three radii of the ellipsoid or edge of the cube ($m$)
nbr_cavities	array (double)	Number of cavities that must be digged
type	string	Type of cavities; must be full or void
min_radius	array (double)	Minimum radius of a cavity $(m)$
max_radius	array (double)	Maximum radius of a cavity $(m)$

Example :

c_geometry = tools.generateGeometry('cube',15,100,'void',0.2,1.2)

e_geometry = tools.generateGeometry('ellipsoid',[1,0.5,0.5],5,'full',0.05,0.11)

Modify an existing geometry (modifyGeometry)

One can modify a pre-existing entirely filled geometry to insert cavities or heterogeneity using the modifyGeometry function, that takes the following parameters :

Arguments :

The radius of the cavities is randomised between min_radius and max_radius

Fields	Type	Description
previous_geometry	pde.DiscreteGeometry	Geometry to modify
shape	string	'cube' or 'ellipsoid'
unit	array (double)	three radii of the ellipsoid or edge of the cube (cm)
nbr_cavities	array (double)	Number of cavities that must be digged
type	string	Type of cavities; must be full or void
min_radius	array (double)	Minimum radius of a cavity (mm)
max_radius	array (double)	Maximum radius of a cavity (mm)

Example :

cube = tools.importGeometry('Cube.stl');
c_geometry = tools.modifyGeometry(cube, 'cube', 2, 30, 'full', 0.1, 0.9);

ellipsoid = tools.importGeometry('Ellipsoid.stl');
e_geometry = tools.modifyGeometry(ellipsoid, 'ellipsoid',[1,0.5,0.5], 30, 'void', 0.05, 0.11);