Shells and solid elements can be made of composites in which several layers of
different materials (plies) are bonded together to form a cohesive structure.
Typically, the plies are made of unidirectional fibers or
of woven fabrics and are joined together by a bonding medium (matrix). Composite
Shells are modeled based on PCOMP, PCOMPP, or
PCOMPG properties assigned to shell elements, while Continuum
Shells are modeled based on PCOMPLS property assigned to solid
elements. For Composite Shells, the plies are assumed to be laid in layers parallel
to the middle plane of the shell. Each layer may have a different thickness and
different orientation of fiber directions. Figure 1. Four-layer Composite Shell with Ply Angle
Classical lamination theory is used to calculate effective stiffness and mass density of the
composite shell. This is done automatically within the code using the properties of
individual plies. The homogenized shell or solid properties are then used in the
analysis.
After the analysis, the stresses and strains in the individual layers and between the layers can be calculated from the overall shell stresses and strains. These results may then be used to assess the failure indices of individual plies and of the bonding matrix.
