how to set the external stresses

Hi everyone,

For fix npt command, the external stresses cannot be set if the associated dimension is not periodic. If I want to add a stress in the non-periodic direction, how to do it?

Regards,

Yongning

Since there is a free surface in that dimension,
what does it mean to have an “external stress”
applied, and how are you thinking it would
be applied physically?

Steve