Effect of compressive transverse normal stress on mode II fracture toughness in polymeric composites |
| |
Authors: | Qida Bing C T Sun |
| |
Affiliation: | (1) School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907, USA;(2) Present address: Syracuse University, Syracuse, NY 13244, USA |
| |
Abstract: | Effect of transverse normal stress on mode II fracture toughness of unidirectional fiber reinforced composites was studied
experimentally in conjunction with finite element analyses. Mode II fracture tests were conducted on the S2/8552 glass/epoxy
composite using off-axis specimens with a through thickness crack. The finite element method was employed to perform stress
analyses from which mode II fracture toughness was extracted. In the analysis, crack surface contact friction effect was considered.
It was found that the transverse normal compressive stress has significant effect on mode II fracture toughness of the composite.
Moreover, the fracture toughness measured using the off-axis specimen was found to be quite different from that evaluated
using the conventional end notched flexural (ENF) specimen in three-point bending. It was found that mode II fracture toughness
cannot be characterized by the crack tip singular shear stress alone; nonsingular stresses ahead of the crack tip appear to
have substantial influence on the apparent mode II fracture toughness of the composite. |
| |
Keywords: | Polymer-matrix composites Mode II fracture toughness Transverse normal stress Stress singularity Off-axis specimen ENF specimen |
本文献已被 SpringerLink 等数据库收录! |
|