Add cubic and quadratic nonlinearities

README.md

@@ -93,6 +93,7 @@ the code. Some of those feature can be discussed and are not mandatory:
 - Check if multiple materials already works or if continuity and boundary
   conditions are needed
 - Add test for thermal simulation with convective boundary condition
+- Put all nonlinear options into one data class
 
 ### Issues
 

plutho/__init__.py

@@ -1,6 +1,7 @@
 from .simulation import PiezoSimTime, ThermoPiezoSimTime, MeshData, \
     SimulationData, MaterialData, SimulationType, ModelType, \
-    ThermoSimTime, NonlinearType
+    ThermoSimTime, NonlinearType, NLPiezoHB, NLPiezoTime, \
+    Nonlinearity
 from .io import parse_charge_hist_file, parse_displacement_hist_file, \
     create_vector_field_as_csv, create_scalar_field_as_csv
 from .postprocessing import calculate_impedance, \
@@ -9,4 +10,3 @@
 from .single_sim import SingleSimulation, FieldType
 from .mesh import Mesh
 from .coupled_sim import CoupledThermoPiezoThermoSim, CoupledFreqPiezoTherm
-from .nonlinear_sim import PiezoNonlinear