Morphology and compression‐after‐impact strength relationship in interleaved toughened composites

Abstract

Morphology and compression after impact (CAI) strength relationships in interleaved toughened high performance composites are investigated using a quantitative two‐dimensional image analysis approach. A group of six quasi‐isotropic carbon fiber‐epoxy composites with identical compositions, but having variations in CAI strengths, were analyzed to study how the interleaf particle size, particle size distribution, and location of particles in the interlaminar region affect the CAI strength values and the corresponding damage mechanisms. It is found that the CAI strength of interleaved‐toughened composites is significantly affected by the size and size distribution of toughener particles in the interlaminar regions of the composite. In general, high CAI strength composites exhibit more uniform particle size distribution throughout the interlaminar regions. Whereas, for low CAI strength composites, the interleaf particles tend to cluster together and have varied size distribution.

B‐staged epoxy/single‐walled carbon nanotube nanocomposite thin films for composite reinforcement

“…These imperfections can significantly compromise the nanocomposite properties, especially the mechanical properties. A high degree of dispersion of SWCNTs in thin‐film interleaves is needed to achieve high compression after impact strength in composites 26…”

“…A high degree of dispersion of SWCNTs in thin-film interleaves is needed to achieve high compression after impact strength in composites. 26 The oxidation of SWCNTs and the following reaction with the PAMAM G0 dendrimer has been shown to be an effective approach to functionalize SWCNTs, especially for the preparation of epoxy-based nanocomposites. 35 The dispersion and distribution of SWCNTs in the polymer matrix have been mainly characterized by scanning electron microscopy and transmission electron microscopy.…”

“…Specifically, B‐staged thin films are to be used as interleaves to enhance the conductivity, interlaminar strength, and toughness of laminated VARTM composites 22–27. The increase in the interlaminar strength and toughness can, in turn, improve the compression after impact strength of the composites 22, 26. Thus, thin films containing well‐dispersed SWCNTs, which usually exhibit improved modulus and toughness,11 appear to be ideal candidates for the reinforcement of laminated composites.…”

“…[22][23][24][25][26][27] The increase in the interlaminar strength and toughness can, in turn, improve the compression after impact strength of the composites. 22,26 Thus, thin films containing well-dispersed SWCNTs, which usually exhibit improved modulus and toughness, 11 appear to be ideal candidates for the reinforcement of laminated composites. As described in the literature, a number of approaches have been developed to incorporate nanotubes into laminated composites and have been shown to be effective.…”

Compression–After–Impact Strength and Surface Morphology in Toughened Composite Materials

“…toughened particle morphology relationships in toughened composites have been reported in the literature (Derkowski and Sue, 2003). Past studies have typically been conducted by using Optical Microscopy or Scanning Electron Microscopy for observation of localized microstructures of toughened particles.…”