diff --git a/python/damask/_result.py b/python/damask/_result.py index e46671917..5d04a79b7 100644 --- a/python/damask/_result.py +++ b/python/damask/_result.py @@ -1201,7 +1201,7 @@ class Result: 'label': f"epsilon_{t}^{m}({F['label']})", 'meta': { 'unit': F['meta']['unit'], - 'description': f'strain tensor of order {m} based on {side} stretch tensor '+\ + 'description': f'Seth-Hill strain tensor of order {m} based on {side} stretch tensor '+\ f"of {F['label']} ({F['meta']['description']})", 'creator': 'add_strain' } @@ -1210,10 +1210,11 @@ class Result: F: str = 'F', t: Literal['V', 'U'] = 'V', m: float = 0.0): - """ - Add strain tensor of a deformation gradient. + r""" + Add strain tensor (Seth-Hill family) of a deformation gradient. - For details, see damask.mechanics.strain. + By default, the logarithmic strain based on the + left stretch tensor is added. Parameters ---------- @@ -1247,6 +1248,23 @@ class Result: spatial/Eulerian strain measures (based on 'V') for elastic strains when calculating averages. + The strain is defined as: + + .. math:: + + m = 0 \\\\ + \vb*{\epsilon}_V^{(0)} = \ln (\vb{V}) \\\\ + \vb*{\epsilon}_U^{(0)} = \ln (\vb{U}) \\\\ + + m \neq 0 \\\\ + \vb*{\epsilon}_V^{(m)} = \frac{1}{2m} (\vb{V}^{2m} - \vb{I}) \\\\ + \vb*{\epsilon}_U^{(m)} = \frac{1}{2m} (\vb{U}^{2m} - \vb{I}) + + References + ---------- + | https://en.wikipedia.org/wiki/Finite_strain_theory + | https://de.wikipedia.org/wiki/Verzerrungstensor + """ self._add_generic_pointwise(self._add_strain,{'F':F},{'t':t,'m':m})