Positive definite stress-strain matrix
Dear friends,
I'm an MSc. student at Bogazici University, Turkiye and I'm working on a thesis project about the failure behaviour of fiber reinforced laminated composite plates under different loading types. The material which we use are AS4 fiber reinforced prepregs and their mechanical properties are the following:
E11 =134,000 MPa
E22 = E33= 9480 MPa
G12 = G13= 5490 MPa
G23 MPa =3272
nu12 = nu13 =0.271
nu23 =0.448