# Material Properties (Isotropic, 3D Transverseley Isotropic, 3D Orthotropic)

*Known Limitation: The material coordinate system is without function. The global coordinate system acts always as the material coordinate system. The global x-axis is always the build direction. As a workaround the part can be aligned using the Transform Tool.*

Three different materials can be set up in MSC Apex Generative Design:

### Isotropic Material

The properties of Isotropic material are uniformly in all directions. Therefore, only one Young's modulus, one Poisson’s ratio and one Tension (Tensile) Strength is needed.

### 3D Transversely Isotropic Material

The properties of 3D Transversely Isotropic material are directional dependent. One direction (axial / build direction) differs from the two other in-plane directions. The x-axis is always the build direction, the y- and z-direction are the in-plane directions. As an input the Young's modulus for the build direction as well as for the in-plane directions (Ey=Ez) are needed. Furthermore, the Shear Modulus and the two Poisson’s ratios for in-plane and axial are desired. All further necessary values are calculated in the background.

For the material limits the Tension Strength in build direction (Axis) and for the in-plane directions as well as the transversal Shear Strength can be set up. With the Failure Criteria FFF Thumb Rule and directional dependent Tsai-Hill the different material limits can be considered.

Optional the Compression Strength can be set up. With the directional dependent Tsai-Wu Failure Criterion the difference between tension and compression can be considered besides the directional dependency.

### 3D Orthotropic Material

The properties of 3D Orthotropic material are directional dependent. For every main axis a different Young's modulus is needed as well as Shear Moduli for all planes and the Poisson’s ratios.

For the material limits the Tension Strength in build direction (Axis) and in-plane directions as well as the transversal Shear Strength can be set up. With the Failure Criteria FFF Thumb Rule and directional dependent Tsai-Hill the material limits differences can be considered.

Optional the Compression Strength can be filled in. With the directional dependent Tsai-Wu Failure Criterion the difference between tension and compression can be considered besides the directional dependency.