cratepy.material.materialoperations.compute_spatial_log_strain

compute_spatial_log_strain(def_gradient)

Spatial logarithmic strain from deformation gradient.

\[\boldsymbol{\varepsilon} = \frac{1}{2} \ln (\boldsymbol{F} \boldsymbol{F}^{T})\]

where \(\boldsymbol{\varepsilon}\) is the spatial logarithmic strain tensor and \(\boldsymbol{F}\) is the deformation gradient.

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Parameters:

def_gradient (numpy.ndarray (2d)) – Deformation gradient.

Returns:

spatial_log_strain – Spatial logarithmic strain.

Return type:

numpy.ndarray (2d)