Abstract
The digital birefringent-coating (DBC) system and finite element method (FEM) were used to study the fracture behavior for laminates of carbonfiber reinforced plastics (CFRPs) containing a central crack. Different crack orientations in different unidirectionally reinforced specimens were tested. The results show that the orthotropic fracture theory cannot adequately describe the fracture behavior of the CFRP laminates. There-fore, the widely used orthotropic fracture theory needs to be re-examined in detail. © 1991.