AN ANALYSIS OF CURVATURE AND LAYUP EFFECTS ON DELAMINATION IN NOTCHED COMPOSITE BEAMS Academic Article uri icon

abstract

  • Two-dimensional finite element modeling has been used to determine strain energy release rates for delamination cracks in straight and curved notched tensile beams. The notched tensile beam (NTB) is a low-order analog of a cylindrical pressure vessel with an external part-through hole. The material was an S-glass/epoxy fiber rein forced composite material. Specimens were 8 plies thick with notches 2 and 4 plies deep. Uni-directional [0]8 and multi-directional [0,0, +77, -77]2 layups have been in vestigated. Strain energy release rates were calculated using the virtual crack closure tech nique. The finite element results reveal a mode II dominance similar to the cracked lap shear (CLS) specimen. The effect of curvature was to lower the strain energy release rates slightly (5-13%). Total strain energy release rates were generally higher for the multi- directional layup (by 1 to 3 times), but the GII/G I ratio may increase or decrease depend ing on the notch depth and the orientation of the plies bounding the delamination.

published proceedings

  • JOURNAL OF REINFORCED PLASTICS AND COMPOSITES

author list (cited authors)

  • HARBERT, S. J., & HOGAN, H. A.

citation count

  • 1

complete list of authors

  • HARBERT, SJ||HOGAN, HA

publication date

  • April 1992