1.. index:: compute smd/ulsph/stress 2 3compute smd/ulsph/stress command 4================================ 5 6Syntax 7"""""" 8 9.. code-block:: LAMMPS 10 11 compute ID group-ID smd/ulsph/stress 12 13* ID, group-ID are documented in :doc:`compute <compute>` command 14* smd/ulsph/stress = style name of this compute command 15 16Examples 17"""""""" 18 19.. code-block:: LAMMPS 20 21 compute 1 all smd/ulsph/stress 22 23Description 24""""""""""" 25 26Define a computation that outputs the Cauchy stress tensor. 27 28See `this PDF guide <PDF/SMD_LAMMPS_userguide.pdf>`_ to using Smooth 29Mach Dynamics in LAMMPS. 30 31Output info 32""""""""""" 33 34This compute calculates a per-particle vector of vectors (tensors), 35which can be accessed by any command that uses per-particle values 36from a compute as input. See the :doc:`Howto output <Howto_output>` doc 37page for an overview of LAMMPS output options. 38 39The values will be given in :doc:`units <units>` of pressure. 40 41The per-particle vector has 7 entries. The first six entries 42correspond to the xx, yy, zz, xy, xz, yz components of the symmetric 43Cauchy stress tensor. The seventh entry is the second invariant of the 44stress tensor, i.e., the von Mises equivalent stress. 45 46Restrictions 47"""""""""""" 48 49This compute is part of the MACHDYN package. It is only enabled if 50LAMMPS was built with that package. See the :doc:`Build package <Build_package>` page for more info. This compute can 51only be used for particles which interact with the updated Lagrangian 52SPH pair style. 53 54Related commands 55"""""""""""""""" 56 57:doc:`compute smd/ulsph/strain <compute_smd_ulsph_strain>`, :doc:`compute smd/ulsph/strain/rate <compute_smd_ulsph_strain_rate>` :doc:`compute smd/tlsph/stress <compute_smd_tlsph_stress>` 58 59Default 60""""""" 61 62none 63