Development of a new fracture test to identify the critical energy release rate: The Tensile Flexure test on Notched Specimen

Delamination is one of the most critical damage mechanisms in laminated composites. A fracture test, referenced in the following as Tensile Flexure test on Notched Specimen, is proposed in this work to characterize the propagation of delamination. After the description of the experimental procedure, experimental results on carbon/epoxy specimens are presented to describe the capabilities and advantages of the test to characterize delamination. Then, a new propagation law is proposed to describe the evolution of the fracture toughness. Finally, a non-deterministic analysis is performed to determine the influence of the measured parameters on the toughness identification.

► New fracture test characterizes the fracture toughness of multidirectional interfaces.
► Two cracks propagate under evolving mixed-mode ratio during the test.
► Determination of the fracture toughness evolution is done using only the new test.
► New propagation law adapted to carbon/epoxy materials is evaluated.