Fatigue characterization of Poly Vinyl Chloride (PVC) foam core sandwich composite using the G-control method. (May 2016)

• Record Type: Journal Article
• Authors: Manca, Marcello; Berggreen, Christian; Carlsson, Leif A; Bortolotti, Pietro
• Is Part Of: Journal of sandwich structures & materials. Volume 18:Number 3(2016:May)
• Page Start: 374
• Page End: 394
• Publication Date: 2016-05
• Subjects: Sandwich -- interface -- fracture characterization -- energy release rate -- crack propagation; Sandwich construction -- Periodicals; 624.177905
• DOI: 10.1177/1099636215603049
• Languages: English
• ISSNs: 1099-6362

Abstract

This paper presents experimental results from cyclic crack propagation tests performed on sandwich specimens with glass/epoxy face sheets and Poly Vinyl Chloride (PVC) foam cores using the G-controlled cyclic energy release rate (ΔG) test procedure. The face material was tested in tension, compression and shear to determine in-plane and out-of-plane mechanical properties, such as Young's modulus, Poisson's ratio and shear modulus. These properties were then used in an analytical model of the mixed-mode bending sandwich specimen to calculate compliance and energy release rate. Finite element analysis was used to determine the mode-mixity of the crack loading. Experimental crack growth cyclic tests were carried out on pre-cracked mixed-mode bending sandwich specimens with H45, H100 and H160 PVC foam cores under two mode-mixities (mode I and mode II dominant). Post-mortem analysis was performed on tested specimens, highlighting the influence of mode mixity and foam density on the crack path. Crack propagation diagrams showing da/dN versus ΔG curves were obtained to establish the Paris-Erdogan relation for each material combination tested at the two mode-mixities. Results showed constant crack growth rates for all the materials tested and revealed the influence on mode-mixity on crack propagation speed and foam density (higher foam density, slower crack propagation).