Tasa de liberación de energía equivalente y estabilidad de grieta en la configuración ENFR de modo mixto I/II

Crack propagation performance in the ENFR (End Notched Flexure test with roller) test configuration is analyzed. The test configuration is based on the ENF test with a roller introduced between the two surfaces of the crack in order to get mixed-mode. Based on the reliability of the linear criterion, an equivalent energy release rate is proposed taking into account the interaction between the two modes and II. The stability of the crack propagation is defined by means of the derivative of the proposed equivalent energy release rate. Experimental tests with specimens of F593/T300 carbon/epoxy unidirectional composite have been carried out to assess the proposed equivalent energy release rate and to evaluate the crack stability condition. Finally, some recommendations for performing tests in the ENFR configuration under optimum conditions are summarized.