Analysis of notched woven composites and fiber metal laminates with previous fatigue damage. (March 2016)

• Record Type: Journal Article
• Authors: Rubio-González, C; Velasco, F; Martínez, J
• Is Part Of: Journal of composite materials. Volume 50:Number 7(2016)
• Page Start: 885
• Page End: 897
• Publication Date: 2016-03
• Subjects: Hybrid composite -- fatigue damage -- stress concentration -- damage tolerance; Composite materials -- Periodicals; Composites -- Périodiques; 620.118
• DOI: 10.1177/0021998315583318
• Languages: English
• ISSNs: 0021-9983

Abstract

Fiber metal laminates are hybrid materials consisting of alternating layers of thin metallic sheets and fiber reinforced epoxy prepregs. In this work, the fatigue damage effect on the residual strength, stiffness, and strain field in woven carbon-reinforced aluminum laminates with a circular open hole is studied. The strain fields were obtained by means of a noncontact optical deformation measuring system and then used to determine the normal stress distribution around the open hole. A squared pattern is observed in the strain mapping of the specimens with previous fatigue damage that disturbed the stress profile. The experimental stress profiles were compared with finite element modeling and an analytic solution; clear agreement is observed on this comparison for fatigue damage free specimens, except near the hole edge due to stress redistribution. Previous fatigue damage reduces residual strength and stiffness of notched woven composite samples and fiber metal laminates; it was also observed that notched fiber laminates are more fatigue tolerant than the base composite material. It is important to note that the fatigue loading caused not only damage such as matrix cracking and delamination, but also a weave style strain/stress redistribution along the warp direction.