Documentation

How to install Simcoon

The easiest way to install simcoon is to create a conda environnement: You can utilize the Anaconda GUI or type: (for the installation of an environment called “scientific”)

conda create --name scientific

To activate the environment:

conda activate scientific

The next step is to install the required packages:

conda install -c conda-forge armadillo conda install -c conda-forge boost conda install -c conda-forge cgal conda install -c conda-forge numpy

Next, after downloading the simcoon sources in the github repository of Simcoon. Unzip the content in a folder and modify the Install.sh source file to look after you conda environnement path:

anacondaloc=/path/to/anaconda/anaconda3/envs/scientific

The last step is to run the installation script:

sh Install.sh

##Simcoon first steps

We first import simmit (the python simulation module of simcoon) and numpy

import numpy as np
from simcoon import simmit as sim

Then, suppose we would like to compute the stiffness tensor (in the form of a 6x6 matrix) of a linear elastic material, providing the Young’s modulus \(E\) and the Poisson’s ratio \(\nu\):

E = 70000.0
nu = 0.3
L = sim.L_iso(E,nu,"Enu")
print np.array_str(L, precision=4, suppress_small=True)

Conversely, one can ask Simcoon to output he material properties, providing s stiffness tensor:

x = sim.L_iso_props(L)
print(x)

Simcoon can also check the symetries of a provided stiffness tensor and ouput the set of material parameter, if a specific symmetry has been found:

d = sim.check_symetries(L)
print(d['umat_type'])
print(d['props'])

##Simcoon tutorial

Probably the first thing you would like to do with Simcoon is to simulate the mechanical response corresponding of a simple tension test, considering an elastic isotropic material:

We first import simmit (the python simulation module of simcoon) and numpy

import numpy as np
from simcoon import simmit as sim

Next we shall define the material constitutive law to be utilized and the associated material properties. We will pass them as a numpy array:

umat_name = 'ELISO' #This is the 5 character code for the elastic-isotropic subroutine
nstatev = 1 #The number of scalar variables required, only the initial temperature is stored here to consider the thermal expansion if temperature changes.

E = 700000. #The Young modulus
nu = 0.2 #The Poisson coefficient
alpha = 1.E-5 #The coefficient of thermal expansion

#Three Euler angles to represent the material orientation with respect to the reference basis (in which the loading is expressed)
psi_rve = 0.
theta_rve = 0.
phi_rve = 0.

#Solver_type define the solver strategy (only a classical newton scheme is actually implemeted for now), and the corate_type define the type of corotational spin rate (0 for Jauman, 1 for Green-Naghdi, 2 for logarithmic)
solver_type = 0
corate_type = 2

props = np.array([E, nu, alpha])

The last part of the script is to define, if wanted, the location of the data input files (i.e., to define the loading path), and the results outut file and location:

path_data = 'data'
path_results = 'results'
pathfile = 'path.txt'
outputfile = 'results_ELISO.txt'

The last part is to define the loading path. Further details about this file is given in the Simcoon documentation, but for instance you could just create a folder ‘data’ and create a text file named ‘path.txt’ with the following inside:

#Initial_temperature
293.5
#Number_of_blocks
1

#Block
1
#Loading_type
1
#Control_type(NLGEOM)
1    
#Repeat
1
#Steps
1

#Mode
1
#Dn_init 1.
#Dn_mini 0.1
#Dn_inc 0.01
#time
30.
#mechanical_state
E 0.01 
S 0 S 0
S 0 S 0 S 0
#temperature_state
T 293.5

The latter correspond to a pure strain-controlled tension test in the direction 1 up to 1% strain, at the temperature 293.5K.

You can now run your just created python file (you could also create a jupyter notebook, or run the notebook ELISO.ipynb that you can find in the examples). You will now find in the ‘results’ folder a file named results_ELISO.txt. Have a look at the existing notebook or in the documentation to know how to analyse the result file. The documentation of the latest version of simcoon can be found here: Simcoon documentation.

History of API of simcoon

v1.9.0

The new version of simcoon has been released! It includes many new features, notably:

New functions for finite strain, especially to define objective stress rates (Jaumann, Green-Naghdi)
Generation of Periodic boundary conditions for Thermal-Mechanical studies of periodic Unit Cells (boxes)
Tests for regular contitutive models and identification tools

v1.8

Added the possibility/examples to develop an Abaqus UMAT with the simcoon API

v1.7

Added thermomechanical couplings of viscoelastic materials (Prony series or Zener with N branches)

v1.6

Added thermomechanical couplings for most basic constitutive models, except N-branches viscoelasticity

v1.5

Added tools for the definition of Abaqus input files automatically: steps, materials and sections

v1.4

Added tools for the generation of periodic boundary condition for parallelepipedic unit cells, considering non-periodic meshes.

v1.3

Added tools for the generation of periodic boundary condition for parallelepipedic unit cells

v1.2

Addition of Finite strain functions the API

v1.1

Addition of thermomechanical constitutive laws for:

elasticity, plasticity, phase transformation (shape memory alloys)

v1.0

Stable version of simcoon that contained the followinf features:

Non-linear solver working with infinitesimal strains
constitutive equations for elasticity, plasticity, viscoelasticity, phase transformation (shape memory alloys)
identification tool
micromechanical algorithms and periodic layers

v0.9

First release of simcoon: Basic features from the former ‘smartplus’ library

Yves Chemisky