PAC3D ---------- .. automodule:: classes This class represents a slender soft body under the Piecewise Affine Curvature (PAC) hypothesis with elongation. The strain is modeled as .. math:: \boldsymbol{\xi}(\boldsymbol{q}, s) = \boldsymbol{\Phi}(s)\boldsymbol{q} + \boldsymbol{\xi}_{0} = \frac{1}{L_0} \left(\begin{array}{ccccc} -1 & -s & 0 & 0 & 0 \\ 0 & 0 & 1 & s & 0 \\ 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 0 \\ 0 & 0 & 0 & 0 & 1 \end{array}\right)\boldsymbol{q} + \left(\begin{array}{c} 0 \\ 0 \\ 0 \\ 0 \\ 0 \\ 1 \end{array}\right), where :math:`\boldsymbol{q} \in \mathbb{R}^{5 \times 1}` is the vector of configuration variables and :math:`s \in [0, L_{0}]` the curvilinear abscissa, with :math:`L_{0}` the body rest length. .. autoclass:: PAC3D :show-inheritance: :members: