Transfer helpers (Voigt <-> matrix)

simcoon.simmit.v2t_strain(input: Annotated[numpy.typing.ArrayLike, numpy.float64], copy: bool = True) → numpy.typing.NDArray[numpy.float64]

Transform a strain Voigt vector into a 3x3 strain matrix.

Parameters:

input (pybind11::array_t<double>) – A 6-element Voigt vector representing strain in the order [e11, e22, e33, e23, e13, e12].
copy (bool, optional) – If true, a copy of the returned array is made. Default is true.

Returns:

A 3x3 matrix with the full small-strain tensor corresponding to the input Voigt vector. Shear components are placed using engineering shear convention (e.g., e12 stored in position (0,1) and (1,0)).

Return type:

pybind11::array_t<double>

Notes

This wrapper calls the underlying C++ helper which converts a 6-component Voigt column vector into a symmetric 3x3 matrix.

Examples

import numpy as np
import simcoon as sim

v = np.array([0.1, 0.0, 0.0, 0.0, 0.0, 0.0])
M = sim.v2t_strain(v)
print(M)

simcoon.simmit.t2v_strain(input: Annotated[numpy.typing.ArrayLike, numpy.float64], copy: bool = True) → numpy.typing.NDArray[numpy.float64]

Transform a 3x3 strain matrix into a 6-element strain Voigt vector.

Parameters:

input (pybind11::array_t<double>) – A 3x3 symmetric strain matrix.
copy (bool, optional) – If true, a copy of the returned array is made. Default is true.

Returns:

A 6-element Voigt column vector in the order [e11, e22, e33, e23, e13, e12].

Return type:

pybind11::array_t<double>

Notes

The conversion uses the engineering shear components convention. The resulting vector is suitable for functions that expect Voigt-form strains.

Examples

import numpy as np
import simcoon as sim

M = np.array([[0.1, 0.0, 0.0], [0.0, 0.0, 0.0], [0.0, 0.0, 0.0]])
v = sim.t2v_strain(M)
print(v)

simcoon.simmit.v2t_stress(input: Annotated[numpy.typing.ArrayLike, numpy.float64], copy: bool = True) → numpy.typing.NDArray[numpy.float64]

Transform a stress Voigt vector into a 3x3 stress matrix.

Parameters:

input (pybind11::array_t<double>) – A 6-element Voigt vector representing stress in the order [s11, s22, s33, s23, s13, s12].
copy (bool, optional) – If true, a copy of the returned array is made. Default is true.

Returns:

A 3x3 symmetric stress matrix.

Return type:

pybind11::array_t<double>

Notes

Shear components follow the engineering convention. This wrapper simply maps the Voigt components into the 3x3 matrix used by the C++ core.

Examples

import numpy as np
import simcoon as sim

s = np.array([100.0, 0.0, 0.0, 0.0, 0.0, 0.0])
S = sim.v2t_stress(s)
print(S)

simcoon.simmit.t2v_stress(input: Annotated[numpy.typing.ArrayLike, numpy.float64], copy: bool = True) → numpy.typing.NDArray[numpy.float64]

Transform a 3x3 stress matrix into a 6-element stress Voigt vector.

Parameters:

input (pybind11::array_t<double>) – A 3x3 symmetric stress matrix.
copy (bool, optional) – If true, a copy of the returned array is made. Default is true.

Returns:

A 6-element Voigt column vector in the order [s11, s22, s33, s23, s13, s12].

Return type:

pybind11::array_t<double>

Notes

This conversion is the inverse of v2t_stress and uses the same engineering shear convention.

Examples

import numpy as np
import simcoon as sim

S = np.zeros((3,3))
S[0,0] = 100.0
v = sim.t2v_stress(S)
print(v)