MODE-II FRACTURE TESTS ON FIBER-REINFORCED PLASTICS

A new testing technique designed to measure the intralaminar shear pro perties (mode II) of fibre-reinforced plastics on notched rectangular specimens is presented. The tests and evaluation procedures are based on the fracture energy concept. The shear test method is experimentall y simple; the loading device as well as the sample geometry are small, and hence, well suited for low-temperature experiments on both unirra diated and irradiated samples. Experiments carried out at room tempera ture and at 77 K, on a two-dimensionally glass fibre-reinforced epoxy (Isoval 10), are presented. Results of acoustic emission and fractogra phic examinations as well as investigations concerning the influence o f the sample geometry on the measured fracture mechanical quantities a re discussed. Advantages and disadvantages of the new testing techniqu e are assessed and compared to other shear tests.