Layup sequence notation

[ZEB31]

Hi - I have come across a notation for composite laminate sequence / layup that I am not used to - can anyone help? I am used to seeing for example [0,45,90]s but I have just read [0, 45, 90]so - is anyone familiar with this difference and what it means?

 

[RPstress]

Not for certain, but symmetry about the rightmost ply is often indicated by s_bar (an overline above the s), which is often hard to reproduce; I've no idea how to make the computer do it. ( [0/45/90]s_bar is [0/45/90/45/0] whereas [0/45/90]s is [0/45/90/90/45/0] .) It might possibly alternatively mean antisymmetric, though this is more often 'as' where [0/45/90]as is [0/45/90/90/-45/0]. Sorry not to be more definitive. Does anyone have a handy source of such notation? NASA RP 1351 uses a T for the total laminate and puts the bar above the ply angle that goes on the centreline, not above the 's'. No 'o's though.