Given the material properties of a unidirectional lamina, this calculator constructs the stiffness matrix [C] and the compliance matrix [S] of the lamina in the principal directions.
If the angle of rotation of the lamina is given (other than 0 degree), this calculator also constructs the stiffness matrix  and the compliance matrix  in the rotated directions.
|Stress-Strain Relations for Lamina for Principal Directions
The stiffness matrix [C] in the principal directions is
The compliance matrix [S] in the principal direction is
|Coordinate Transformation Matrix
The engineering-tensor interchange matrix [R] is
|Stiffness and Compliance Matrices for Angled Lamina
The stiffness matrix for a lamina of arbitry orient can be expressed in terms of the stiffness matrix in the principal direction,
The complicance matrix for a lamina of arbitry orient can be obtained in a similar manner.