Orthotropic materials have three mutually perpendicular planes of elastic symmetry.
- Modulus of Elasticity – Longitudinal (E1)
Modulus of elasticity in the longitudinal direction. It also defined as the fiber direction or 1-direction.
- Modulus of Elasticity – Lateral (E2)
Modulus of elasticity in lateral direction. It also defined as the matrix direction or 2-direction.
- Poisson’s Ratio (NU12)
The ratio of lateral strain to longitudinal strain.
- G12
In-plane shear modulus.
- G1Z
Transverse shear modulus in the 1-Z plane.
- G2Z
Transverse shear modulus for shear in the 2-Z plane.
- Mass Density (RHO)
The density of a material is its weight per unit volume (in SI units).
- Thermal Expansion Coefficient (Ai)
Thermal expansion coefficient in the i direction. (Real)
- Reference Temperature (TREF)
The reference temperature for the calculation of thermal loads or a temperature dependent thermal expansion coefficient.
- Xt and Xc
Allowable stresses or strains in tension and compression, respectively, in the longitudinal direction. These values are required if a failure index is desired.
- Yt and Yc
Allowable stresses or strains in tension and compression, respectively, in the lateral direction. These values are required if a failure index is desired.
- S
Allowable stress or strain for in-plane shear.
- Structural Damping Coefficient (GE)
This value is found by multiplying the critical damping ratio C/C0 by 2.0.
- F12
Interaction term in the tensor polynomial theory of Tsai-Wu. Required if the failure index by the Tsai-Wu theory is desired and if the value of F12 is different from 0.0.
- STRN
For the maximum strain theory only. It indicates whether Xt, Xc, Yt, Yc and S are stress or strain allowable. (Real = 1.0, strain allowable; blank for stress allowable)