A NEW COMPARATIVE METHOD TO EVALUATE THE FRACTURE PROPERTIES OF LAMINATED COMPOSITE

In this paper a new method to determine the fracture properties and strain energy release rate for Carbon- Polyester composite has been introduced. Fracture characteristics such as critical stress intensity factor and critical strain energy release rate for mode I, mode II and mixed mode loading were determined using Arcan type specimen. 130 layers of carbon fiber polyester woven composite with each of 0.2mm thickness were put on each other. Theoretical studies to determine strain energy release rate were done using three methods: Corrected Beam Theory (CBT), Compliance Calibration Method (CCM), Virtual Crack Closure Technique (VCCT), and results were recorded and were compared with the results from experimental and numerical attempts. Critical loads were recorded with experimental attempts then applied to the finite element software. Results were recorded and compared with each other to determine the best method. Results show that compliance calibration method and virtual crack closure technique determine strain energy release rate value closer to J-integral in comparison with corrected beam theory. Finally, the fracture surfaces were examined by scanning electron microscope to gain insight the failure responses that shows the fracture surface for mode II is rougher than the fracture surface for mode I and mixed mode.