Experimental and Analytical Evaluation of the Notched Tensile Fracture of CFRP-Woven Laminates at Low Temperatures

Abstract

This paper describes an experimental and analytical study on the cryogenic fracture behavior of CFRP-woven laminates under tension with a sharp notch. Single-Edge Notched Tension (SENT) tests were performed at room temperature, liquid nitrogen temperature (77 K), and liquid helium temperature (4 K). During the SENT tests, AE method was implemented to assist in identifying the occurrence of damage which forms from a notch. The growth of crack from notch tip was characterized by microscopical observation and AE response. A finite element analysis was also carried out to calculate the strain energy release rate and stress intensity factor for SENT specimens. The results of the finite element analysis are used to supplement the experimental data. An example is given to show how the acoustic emission data obtained on SENT specimens can be used to nondestructively test the fracture properties of CFRP-woven laminates at low temperatures.