Hi,
 I am modeling a sandwich composite structure made of 4 Face sheets (1.1mm)+Honey Comb Core (6mm)+4Face sheets (1.1mm) represented by 2d shell elements with Pomp Property & Mat 8 card. Is this the correct way when there is pressure load applied on  normal to elements. 
 The reason I am writing because, Mat 8 card I have used here to represent honey comb core does not take E33 value as an input which I believe is an important property  to account for bending/shear due to pressure load. 
 If the modeling approach is not correct then please suggest me what is the best way to model without going for actual solid elements for pressure load case.
 Thanks and Regards,
 Vijay