MATERIALS & DESIGN, cilt.18, sa.3, ss.131-135, 1997 (SCI-Expanded)
Types and characteristics of defects produced by low-velocity transverse impact loading on (+/-45 degrees(2), 90 degrees) S-glass and (+/-54 degrees(3), 90 degrees) E-glass fibre reinforced epoxy composites were investigated in this study. For both materials, the specimens were in the form of thin-walled cylindrical tubes. A test set-up capable of producing low-velocity transverse impact at energy levels between 3.5 J and 8.5 J was designed and manufactured. Fifteen specimens were tested from each type of composite material. Point-like defects which are the initiation of cracks in the matrix, regular and irregular cracks, and delamination zones caused by impact, were observed. Visual inspection and post-emulsified fluorescent penetrant systems were utilized for damage detection. Type and extent of the damage produced is presented in terms of impact energy. (C) 1998 Elsevier Science Ltd. Ail rights resented.